158 changed files with 4661 additions and 1486 deletions
--- a/.gitea/workflows/job.yaml
+++ b/.gitea/workflows/job.yaml
@ -0,0 +1,46 @@
+name: Build and Upload APK
+
+on:
+  push:
+    branches:
+      - notevault-3  # Trigger für den Hauptbranch
+  pull_request:
+    branches:
+      - notevault-3  # Trigger für Pull Requests in den Hauptbranch
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      # Schritt 1: Checkout des Repositories
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      # Schritt 2: Setup JDK
+      - name: Set up JDK 11
+        uses: actions/setup-java@v2
+        with:
+          java-version: '11'
+
+      # Schritt 3: Installiere Gradle und Baue die APK
+      - name: Build APK
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y wget unzip
+          wget https://services.gradle.org/distributions/gradle-7.4-bin.zip
+          unzip gradle-7.4-bin.zip
+          export PATH=$PWD/gradle-7.4/bin:$PATH
+          ./gradlew clean assembleRelease
+
+      # Schritt 4: Upload der APK
+      - name: Upload APK to Gitea Releases
+        uses: pappasam/gitea-release-action@v1
+        with:
+          gitea_token: ${{ secrets.REGISTRY_PASSWORD }}  # Dein Gitea API-Token
+          gitea_url: 'https://git.fawkes100.de'   # Deine Gitea-URL
+          owner: ${{ secrets.REGISTRY_USER }}             # Dein Gitea-Benutzername
+          repo: 'NoteVault'                  # Dein Repository-Name
+          tag_name: 'v${{ github.sha }}'           # Der Tag für die Version
+          file: 'app/build/outputs/apk/release/app-release.apk'  # Pfad zur APK-Datei
+
--- a/.gitignore
+++ b/.gitignore
@ -16,6 +16,3 @@ local.properties
 /music_database
 /music_database-shm
 /music_database-wal
-/note_database
-/note_database-shm
-/note_database-wal
--- a/.idea/.gitignore
+++ b/.idea/.gitignore
@ -6,4 +6,3 @@
 # Datasource local storage ignored files
 /dataSources/
 /dataSources.local.xml
-/AndroidProjectSystem.xml
--- a/.idea/AndroidProjectSystem.xml
+++ b/.idea/AndroidProjectSystem.xml
@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="AndroidProjectSystem">
-    <option name="providerId" value="com.android.tools.idea.GradleProjectSystem" />
-  </component>
-</project>
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@ -1,10 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <code_scheme name="Project" version="173">
-    <JetCodeStyleSettings>
-      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
-    </JetCodeStyleSettings>
-    <codeStyleSettings language="kotlin">
-      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
-    </codeStyleSettings>
-  </code_scheme>
-</component>
--- a/.idea/codeStyles/codeStyleConfig.xml
+++ b/.idea/codeStyles/codeStyleConfig.xml
@ -1,5 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <state>
-    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
-  </state>
-</component>
--- a/.idea/dataSources.xml
+++ b/.idea/dataSources.xml
@ -1,11 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
  <component name="DataSourceManagerImpl" format="xml" multifile-model="true">
-    <data-source source="LOCAL" name="music_database" uuid="95a3c2ec-2c29-4336-900a-3993de90ae66">
+    <data-source source="LOCAL" name="music_database" uuid="eb23f694-6586-450b-8f6f-a75731d36b96">
      <driver-ref>sqlite.xerial</driver-ref>
      <synchronize>true</synchronize>
      <jdbc-driver>org.sqlite.JDBC</jdbc-driver>
-      <jdbc-url>jdbc:sqlite:$USER_HOME$/.cache/JetBrains/IntelliJIdea2025.1/device-explorer/samsung SM-P610/_/data/data/com.stormtales.notevault/databases/music_database</jdbc-url>
+      <jdbc-url>jdbc:sqlite:$PROJECT_DIR$/music_database</jdbc-url>
      <jdbc-additional-properties>
        <property name="com.intellij.clouds.kubernetes.db.enabled" value="false" />
      </jdbc-additional-properties>
@ -19,53 +19,5 @@
        </library>
      </libraries>
    </data-source>
-    <data-source source="LOCAL" name="note_database" uuid="b3770d7c-0a73-40c6-aab8-010effaa19b6">
-      <driver-ref>sqlite.xerial</driver-ref>
-      <synchronize>true</synchronize>
-      <jdbc-driver>org.sqlite.JDBC</jdbc-driver>
-      <jdbc-url>jdbc:sqlite:$USER_HOME$/.cache/JetBrains/IntelliJIdea2025.1/device-explorer/samsung SM-P610/_/data/data/come.stormborntales.notevault/databases/note_database</jdbc-url>
-      <jdbc-additional-properties>
-        <property name="com.intellij.clouds.kubernetes.db.enabled" value="false" />
-      </jdbc-additional-properties>
-      <working-dir>$ProjectFileDir$</working-dir>
-      <libraries>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/xerial/sqlite-jdbc/3.45.1.0/sqlite-jdbc-3.45.1.0.jar</url>
-        </library>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar</url>
-        </library>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/xerial/sqlite-jdbc/3.45.1.0/sqlite-jdbc-3.45.1.0.jar</url>
-        </library>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar</url>
-        </library>
-      </libraries>
-    </data-source>
-    <data-source source="LOCAL" name="note_database [2]" uuid="ad94cfd9-e485-4151-8bf4-a080c51fa27c">
-      <driver-ref>sqlite.xerial</driver-ref>
-      <synchronize>true</synchronize>
-      <jdbc-driver>org.sqlite.JDBC</jdbc-driver>
-      <jdbc-url>jdbc:sqlite:$PROJECT_DIR$/note_database</jdbc-url>
-      <jdbc-additional-properties>
-        <property name="com.intellij.clouds.kubernetes.db.enabled" value="false" />
-      </jdbc-additional-properties>
-      <working-dir>$ProjectFileDir$</working-dir>
-      <libraries>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/xerial/sqlite-jdbc/3.45.1.0/sqlite-jdbc-3.45.1.0.jar</url>
-        </library>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar</url>
-        </library>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/xerial/sqlite-jdbc/3.45.1.0/sqlite-jdbc-3.45.1.0.jar</url>
-        </library>
-        <library>
-          <url>file://$APPLICATION_CONFIG_DIR$/jdbc-drivers/Xerial SQLiteJDBC/3.45.1/org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar</url>
-        </library>
-      </libraries>
-    </data-source>
  </component>
 </project>
--- a/.idea/deploymentTargetSelector.xml
+++ b/.idea/deploymentTargetSelector.xml
@ -4,7 +4,7 @@
    <selectionStates>
      <SelectionState runConfigName="app">
        <option name="selectionMode" value="DROPDOWN" />
-        <DropdownSelection timestamp="2025-05-03T08:34:29.354537334Z">
+        <DropdownSelection timestamp="2025-04-10T18:07:32.446414465Z">
          <Target type="DEFAULT_BOOT">
            <handle>
              <DeviceId pluginId="PhysicalDevice" identifier="serial=R52N50NLGRT" />
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@ -5,6 +5,7 @@
    <option name="linkedExternalProjectsSettings">
      <GradleProjectSettings>
        <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="gradleJvm" value="#GRADLE_LOCAL_JAVA_HOME" />
        <option name="modules">
          <set>
            <option value="$PROJECT_DIR$" />
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@ -1,50 +0,0 @@
-<component name="InspectionProjectProfileManager">
-  <profile version="1.0">
-    <option name="myName" value="Project Default" />
-    <inspection_tool class="ComposePreviewDimensionRespectsLimit" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="ComposePreviewMustBeTopLevelFunction" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="ComposePreviewNeedsComposableAnnotation" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="ComposePreviewNotSupportedInUnitTestFiles" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="GlancePreviewDimensionRespectsLimit" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="GlancePreviewMustBeTopLevelFunction" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="GlancePreviewNeedsComposableAnnotation" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="GlancePreviewNotSupportedInUnitTestFiles" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewAnnotationInFunctionWithParameters" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewApiLevelMustBeValid" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewDeviceShouldUseNewSpec" enabled="true" level="WEAK WARNING" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewFontScaleMustBeGreaterThanZero" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewMultipleParameterProviders" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewParameterProviderOnFirstParameter" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-    <inspection_tool class="PreviewPickerAnnotation" enabled="true" level="ERROR" enabled_by_default="true">
-      <option name="composableFile" value="true" />
-    </inspection_tool>
-  </profile>
-</component>
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="KotlinJpsPluginSettings">
-    <option name="version" value="2.0.0" />
-  </component>
-</project>
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@ -3,5 +3,10 @@
  <component name="FrameworkDetectionExcludesConfiguration">
    <file type="web" url="file://$PROJECT_DIR$" />
  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="21" project-jdk-type="JavaSDK" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="21" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/build/classes" />
+  </component>
+  <component name="ProjectType">
+    <option name="id" value="Android" />
+  </component>
 </project>
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@ -1,17 +1,14 @@
 plugins {
    alias(libs.plugins.android.application)
-    alias(libs.plugins.kotlin.android)
-    alias(libs.plugins.kotlin.compose)
-    alias(libs.plugins.ksp) // NEU
 }

 android {
-    namespace = "come.stormborntales.notevault"
+    namespace = "com.stormtales.notevault"
    compileSdk = 34

    defaultConfig {
-        applicationId = "come.stormborntales.notevault"
-        minSdk = 24
+        applicationId = "com.stormtales.notevault"
+        minSdk = 29
        targetSdk = 34
        versionCode = 1
        versionName = "1.0"
@ -29,38 +26,28 @@ android {
        sourceCompatibility = JavaVersion.VERSION_11
        targetCompatibility = JavaVersion.VERSION_11
    }
-    kotlinOptions {
-        jvmTarget = "11"
-    }
    buildFeatures {
-        compose = true
+        viewBinding = true
    }
 }

 dependencies {

-    implementation(libs.androidx.core.ktx)
-    implementation(libs.androidx.lifecycle.runtime.ktx)
-    implementation(libs.androidx.activity.compose)
-    implementation(platform(libs.androidx.compose.bom))
-    implementation(libs.androidx.ui)
-    implementation(libs.androidx.ui.graphics)
-    implementation(libs.androidx.ui.tooling.preview)
-    implementation(libs.androidx.material3)
-    implementation(libs.androidx.navigation.compose)
-    implementation(libs.androidx.lifecycle.viewmodel.compose)
-    testImplementation(libs.junit)
-    androidTestImplementation(libs.androidx.junit)
-    androidTestImplementation(libs.androidx.espresso.core)
-    androidTestImplementation(platform(libs.androidx.compose.bom))
-    androidTestImplementation(libs.androidx.ui.test.junit4)
-    debugImplementation(libs.androidx.ui.tooling)
-    debugImplementation(libs.androidx.ui.test.manifest)
-    implementation(libs.androidx.foundation)
-    implementation(libs.androidx.room.runtime)
-    implementation(libs.androidx.room.ktx)
+    implementation(libs.appcompat)
+    implementation(libs.material)
+    implementation(libs.constraintlayout)
    implementation(libs.lifecycle.livedata.ktx)
-    implementation(libs.compose.runtime.livedata)
-    implementation(libs.coil.compose)
-    ksp(libs.androidx.room.compiler)
+    implementation(libs.lifecycle.viewmodel.ktx)
+    implementation(libs.navigation.fragment)
+    implementation(libs.navigation.ui)
+    implementation(libs.room.runtime)
+    implementation(libs.annotation)
+    testImplementation(libs.junit)
+    androidTestImplementation(libs.ext.junit)
+    androidTestImplementation(libs.espresso.core)
+    annotationProcessor(libs.room.compiler)
+    implementation("com.github.chrisbanes:PhotoView:2.3.0")
+    implementation("com.squareup.retrofit2:retrofit:2.9.0")
+    implementation("com.squareup.retrofit2:converter-gson:2.9.0")
+    implementation("com.squareup.okhttp3:logging-interceptor:4.9.1")
 }
--- a/app/src/androidTest/java/com/stormtales/notevault/ExampleInstrumentedTest.java
+++ b/app/src/androidTest/java/com/stormtales/notevault/ExampleInstrumentedTest.java
@ -0,0 +1,25 @@
+package com.stormtales.notevault;
+
+import android.content.Context;
+import androidx.test.platform.app.InstrumentationRegistry;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        assertEquals("com.stormtales.notevault", appContext.getPackageName());
+    }
+}
--- a/app/src/androidTest/java/come/stormborntales/notevault/ExampleInstrumentedTest.kt
+++ b/app/src/androidTest/java/come/stormborntales/notevault/ExampleInstrumentedTest.kt
@ -1,24 +0,0 @@
-package come.stormborntales.notevault
-
-import androidx.test.platform.app.InstrumentationRegistry
-import androidx.test.ext.junit.runners.AndroidJUnit4
-
-import org.junit.Test
-import org.junit.runner.RunWith
-
-import org.junit.Assert.*
-
-/**
- * Instrumented test, which will execute on an Android device.
- *
- * See [testing documentation](http://d.android.com/tools/testing).
- */
-@RunWith(AndroidJUnit4::class)
-class ExampleInstrumentedTest {
-    @Test
-    fun useAppContext() {
-        // Context of the app under test.
-        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
-        assertEquals("come.stormborntales.notevault", appContext.packageName)
-    }
-}
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools">
-
+    <uses-permission android:name="android.permission.INTERNET" />
    <application
            android:allowBackup="true"
            android:dataExtractionRules="@xml/data_extraction_rules"
            android:fullBackupContent="@xml/backup_rules"
+            android:networkSecurityConfig="@xml/network_security_config"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
@ -16,15 +17,18 @@
                android:name=".MainActivity"
                android:exported="true"
                android:label="@string/app_name"
-                android:theme="@style/Theme.NoteVault">
+                android:theme="@style/Theme.NoteVault.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
-        <activity android:name=".FullscreenImageViewerActivity" />

+        <activity android:name=".ui.sheetdisplay.NoteSheetDisplayActivity"
+                  android:theme="@style/Theme.AppCompat.NoActionBar">
+            <!-- Intent Filter hinzufügen, wenn Activity vom Launcher oder externen Apps aufgerufen werden soll -->
+        </activity>
    </application>

 </manifest>
--- a/app/src/main/ic_launcher-playstore.png
+++ b/app/src/main/ic_launcher-playstore.png
--- a/app/src/main/java/com/stormtales/notevault/MainActivity.java
+++ b/app/src/main/java/com/stormtales/notevault/MainActivity.java
@ -0,0 +1,90 @@
+package com.stormtales.notevault;
+
+import android.os.Bundle;
+import android.view.MenuItem;
+import android.view.Menu;
+import android.widget.Toast;
+import androidx.lifecycle.ViewModelProvider;
+import com.google.android.material.navigation.NavigationView;
+import androidx.navigation.NavController;
+import androidx.navigation.Navigation;
+import androidx.navigation.ui.AppBarConfiguration;
+import androidx.navigation.ui.NavigationUI;
+import androidx.drawerlayout.widget.DrawerLayout;
+import androidx.appcompat.app.AppCompatActivity;
+import com.stormtales.notevault.databinding.ActivityMainBinding;
+import com.stormtales.notevault.network.APICallback;
+import com.stormtales.notevault.network.auth.AuthService;
+import com.stormtales.notevault.ui.login.LoginDialog;
+import com.stormtales.notevault.ui.login.LoginViewModel;
+
+public class MainActivity extends AppCompatActivity {
+
+    private AppBarConfiguration mAppBarConfiguration;
+    private ActivityMainBinding binding;
+    private LoginViewModel loginViewModel;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        binding = ActivityMainBinding.inflate(getLayoutInflater());
+        setContentView(binding.getRoot());
+
+        setSupportActionBar(binding.appBarMain.toolbar);
+        binding.appBarMain.toolbar.setOnMenuItemClickListener(item -> {
+            if (item.getItemId() == R.id.auth_action) {
+                showLoginDialog();
+                return true;
+            }
+            return false;
+        });
+        DrawerLayout drawer = binding.drawerLayout;
+        NavigationView navigationView = binding.navView;
+        // Passing each menu ID as a set of Ids because each
+        // menu should be considered as top level destinations.
+        mAppBarConfiguration = new AppBarConfiguration.Builder(
+                R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow)
+                .setOpenableLayout(drawer)
+                .build();
+        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
+        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
+        NavigationUI.setupWithNavController(navigationView, navController);
+
+        loginViewModel = new ViewModelProvider(this).get(LoginViewModel.class);
+        loginViewModel.setAuthService(new AuthService(getApplicationContext()));
+        loginViewModel.getIsLoggedIn().observe(this, isLoggedIn -> {
+            this.invalidateOptionsMenu();
+        });
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        // Inflate the menu; this adds items to the action bar if it is present.
+        getMenuInflater().inflate(R.menu.main, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onSupportNavigateUp() {
+        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
+        return NavigationUI.navigateUp(navController, mAppBarConfiguration)
+                || super.onSupportNavigateUp();
+    }
+
+    @Override
+    public boolean onPrepareOptionsMenu(Menu menu) {
+        MenuItem loginItem = menu.findItem(R.id.auth_action);
+        if (Boolean.TRUE.equals(loginViewModel.getIsLoggedIn().getValue())) {
+            loginItem.setIcon(R.drawable.logout); // Setze das Logout-Symbol
+        } else {
+            loginItem.setIcon(R.drawable.login); // Setze das Login-Symbol
+        }
+        return super.onPrepareOptionsMenu(menu);
+    }
+
+    public void showLoginDialog() {
+        LoginDialog loginDialog = new LoginDialog(loginViewModel);
+        loginDialog.show(getSupportFragmentManager(), "login");
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/MusicDatabase.java
+++ b/app/src/main/java/com/stormtales/notevault/data/MusicDatabase.java
@ -0,0 +1,33 @@
+package com.stormtales.notevault.data;
+
+import android.content.Context;
+import androidx.room.Database;
+import androidx.room.Room;
+import androidx.room.RoomDatabase;
+import androidx.room.TypeConverters;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.dao.SongDao;
+import com.stormtales.notevault.data.sync.DateConverter;
+import com.stormtales.notevault.data.sync.SyncStatusConverter;
+
+@Database(entities = {Song.class, NoteSheet.class}, version = 1, exportSchema = false)
+@TypeConverters({SyncStatusConverter.class, DateConverter.class})
+public abstract class MusicDatabase extends RoomDatabase {
+    public abstract SongDao getSongTable();
+
+    private static volatile MusicDatabase INSTANCE;
+
+    public static MusicDatabase getDatabase(final Context context) {
+        if (INSTANCE == null) {
+            synchronized (MusicDatabase.class) {
+                if (INSTANCE == null) {
+                    INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
+                                    MusicDatabase.class, "music_database")
+                            .build();
+                }
+            }
+        }
+        return INSTANCE;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/dao/SongDao.java
+++ b/app/src/main/java/com/stormtales/notevault/data/dao/SongDao.java
@ -0,0 +1,87 @@
+package com.stormtales.notevault.data.dao;
+
+import androidx.lifecycle.LiveData;
+import androidx.room.*;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.sync.SyncStatus;
+
+import java.util.List;
+
+@Dao
+public interface SongDao {
+    @Insert
+    long insert(Song song);
+
+    @Query("SELECT * FROM song WHERE syncStatus != 1")
+    List<Song> getAllSongs();
+
+    @Update
+    void update(Song song);
+
+    @Insert
+    void insert(List<NoteSheet> noteSheets);
+
+    @Delete
+    void deleteNoteSheets(List<NoteSheet> noteSheets);
+
+    @Query("SELECT * FROM NoteSheet WHERE songID = :songID")
+    List<NoteSheet> getNoteSheetsBySong(int songID);
+
+    @Query("SELECT localFileName FROM NoteSheet WHERE songID = :songID")
+    List<String> getNoteSheetFilesBySongID(int songID);
+
+    @Query("SELECT * FROM Song WHERE syncStatus = :syncStatus")
+    List<Song> getSongsBySyncStatus(SyncStatus syncStatus);
+
+    @Update
+    void updateSongs(List<Song> songs);
+
+    @Query("SELECT * FROM Song WHERE localID IN (:localIDs)")
+    List<Song> getSongsByLocalIDs(List<Integer> localIDs);
+
+    @Query("SELECT * FROM Song WHERE serverID IN (:serverIDs)")
+    List<Song> getSongsByServerIDs(List<String> serverIDs);
+
+    @Query("DELETE FROM Song WHERE serverID IN (:serverIDs)")
+    void deleteSongsByServerIDs(List<String> serverIDs);
+
+    @Query("DELETE FROM SONG WHERE localID IN (:localIDs)")
+    void deleteSongsByLocalIDs(List<Integer> localIDs);
+
+    @Query("SELECT * FROM NoteSheet WHERE songID IN (:localSongIDs)")
+    List<NoteSheet> getNoteSheetsBySongIDs(List<Integer> localSongIDs);
+
+    @Query("SELECT * FROM NoteSheet WHERE songID IN (:songIDs)")
+    List<NoteSheet> getNoteSheetsByLocalFiles(List<Integer> songIDs);
+
+    @Update
+    void updateNoteSheets(List<NoteSheet> uploadedNoteSheets);
+
+    @Query("SELECT localID FROM Song WHERE serverID IN (:serverIDs)")
+    List<Integer> getLocalSongIDsByServerIDs(List<String> serverIDs);
+
+    @Query("SELECT * FROM NoteSheet WHERE serverFileName IN (:serverFileNames)")
+    List<NoteSheet> getNoteSheetsByServerFileNames(List<String> serverFileNames);
+
+    @Query("SELECT * FROM NoteSheet WHERE syncStatus = :status")
+    List<NoteSheet> getNoteSheetsBySyncStatus(SyncStatus status);
+
+    @Query("SELECT * FROM NoteSheet WHERE songID IN (:localSongIDs)")
+    List<NoteSheet> getNoteSheetFilesBySongIDs(List<Integer> localSongIDs);
+
+    @Insert
+    void insertSongs(List<Song> onlyRemoteExistingSongs);
+
+    @Delete
+    void deleteSong(Song song);
+
+    @Query("DELETE FROM NoteSheet WHERE songID = :localID")
+    void deleteNoteSheetsByLocalSongID(int localID);
+
+    @Update
+    void updateNoteSheet(NoteSheet noteSheet);
+
+    @Query("SELECT * FROM NoteSheet WHERE serverFileName =:serverFileName")
+    NoteSheet getNoteSheetByServerFileName(String serverFileName);
+}
--- a/app/src/main/java/com/stormtales/notevault/data/entities/NoteSheet.java
+++ b/app/src/main/java/com/stormtales/notevault/data/entities/NoteSheet.java
@ -0,0 +1,101 @@
+package com.stormtales.notevault.data.entities;
+
+import androidx.room.Entity;
+import androidx.room.Ignore;
+import androidx.room.PrimaryKey;
+import com.stormtales.notevault.data.sync.SyncStatus;
+
+import java.util.Objects;
+
+@Entity
+public class NoteSheet {
+    @PrimaryKey(autoGenerate = true)
+    private int localID;
+    private int songID;
+    private String localFileName;
+    private String serverFileName;
+    private String hash;
+
+    private SyncStatus syncStatus;
+
+    @Ignore
+    public NoteSheet(String localFileName, String hash) {
+        this.localFileName = localFileName;
+        this.hash = hash;
+        this.syncStatus = SyncStatus.CREATED;
+    }
+
+    @Ignore
+    public NoteSheet(int songID, String localFileName, String serverFileName, String hash) {
+        this.songID = songID;
+        this.localFileName = localFileName;
+        this.serverFileName = serverFileName;
+        this.hash = hash;
+        this.syncStatus = SyncStatus.REMOTE_MODIFIED;
+    }
+
+
+    public NoteSheet() {
+
+    }
+
+    public int getLocalID() {
+        return localID;
+    }
+
+    public void setLocalID(int localID) {
+        this.localID = localID;
+    }
+
+    public String getLocalFileName() {
+        return localFileName;
+    }
+
+    public void setLocalFileName(String localFileName) {
+        this.localFileName = localFileName;
+    }
+
+    public String getHash() {
+        return hash;
+    }
+
+    public void setHash(String hash) {
+        this.hash = hash;
+    }
+
+    public String getServerFileName() {
+        return serverFileName;
+    }
+
+    public void setServerFileName(String serverFileName) {
+        this.serverFileName = serverFileName;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) return false;
+        NoteSheet noteSheet = (NoteSheet) o;
+        return localID == noteSheet.localID && Objects.equals(localFileName, noteSheet.localFileName) && Objects.equals(hash, noteSheet.hash);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(localID, localFileName, hash);
+    }
+
+    public int getSongID() {
+        return songID;
+    }
+
+    public void setSongID(int songID) {
+        this.songID = songID;
+    }
+
+    public SyncStatus getSyncStatus() {
+        return syncStatus;
+    }
+
+    public void setSyncStatus(SyncStatus syncStatus) {
+        this.syncStatus = syncStatus;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/entities/Song.java
+++ b/app/src/main/java/com/stormtales/notevault/data/entities/Song.java
@ -0,0 +1,131 @@
+package com.stormtales.notevault.data.entities;
+
+import androidx.room.Entity;
+import androidx.room.Ignore;
+import androidx.room.PrimaryKey;
+import com.stormtales.notevault.data.sync.SyncStatus;
+import com.stormtales.notevault.network.sync.models.SongModel;
+
+import java.time.LocalDateTime;
+import java.util.Objects;
+
+@Entity
+public class Song {
+    @PrimaryKey(autoGenerate = true)
+    private int localID;
+
+    private String serverID;
+    private SyncStatus syncStatus;
+    private LocalDateTime syncTime;
+
+    /**Meta Data of Song*/
+    private String title;
+    private String composer;
+    private String genre;
+    private int year;
+
+    @Ignore
+    public Song(String title, String composer, String genre, int year) {
+        this.title = title;
+        this.composer = composer;
+        this.genre = genre;
+        this.year = year;
+        this.syncStatus = SyncStatus.CREATED;
+    }
+
+    @Ignore
+    public Song(SongModel songModel) {
+        this.serverID = songModel.getServerID();
+        this.title = songModel.getTitle();
+        this.composer = songModel.getComposer();
+        this.genre = songModel.getGenre();
+        this.year = songModel.getYear();
+        this.syncStatus = SyncStatus.SYNCED;
+        this.syncTime = LocalDateTime.now();
+    }
+
+    public Song() {
+    }
+
+    @Ignore
+    public Song(String serverID) {
+        this.serverID = serverID;
+        this.syncStatus = SyncStatus.REMOTE_MODIFIED;
+    }
+
+    public int getLocalID() {
+        return localID;
+    }
+
+    public void setLocalID(int localID) {
+        this.localID = localID;
+    }
+
+    public String getServerID() {
+        return serverID;
+    }
+
+    public void setServerID(String serverID) {
+        this.serverID = serverID;
+    }
+
+    public SyncStatus getSyncStatus() {
+        return syncStatus;
+    }
+
+    public void setSyncStatus(SyncStatus syncStatus) {
+        this.syncStatus = syncStatus;
+    }
+
+    public LocalDateTime getSyncTime() {
+        return syncTime;
+    }
+
+    public void setSyncTime(LocalDateTime syncTime) {
+        this.syncTime = syncTime;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getComposer() {
+        return composer;
+    }
+
+    public void setComposer(String composer) {
+        this.composer = composer;
+    }
+
+    public String getGenre() {
+        return genre;
+    }
+
+    public void setGenre(String genre) {
+        this.genre = genre;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) return false;
+        Song song = (Song) o;
+        return localID == song.localID && Objects.equals(serverID, song.serverID);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(localID, serverID);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/entities/SongNoteSheet.java
+++ b/app/src/main/java/com/stormtales/notevault/data/entities/SongNoteSheet.java
@ -0,0 +1,15 @@
+package com.stormtales.notevault.data.entities;
+
+import androidx.room.Embedded;
+import androidx.room.Relation;
+
+import java.util.List;
+
+public class SongNoteSheet {
+    @Embedded public Song song;
+    @Relation(
+            parentColumn = "localID",
+            entityColumn = "songID"
+    )
+    public List<NoteSheet> noteSheets;
+}
--- a/app/src/main/java/com/stormtales/notevault/data/model/LoggedInUser.java
+++ b/app/src/main/java/com/stormtales/notevault/data/model/LoggedInUser.java
@ -0,0 +1,23 @@
+package com.stormtales.notevault.data.model;
+
+/**
+ * Data class that captures user information for logged in users retrieved from LoginRepository
+ */
+public class LoggedInUser {
+
+    private String userId;
+    private String displayName;
+
+    public LoggedInUser(String userId, String displayName) {
+        this.userId = userId;
+        this.displayName = displayName;
+    }
+
+    public String getUserId() {
+        return userId;
+    }
+
+    public String getDisplayName() {
+        return displayName;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/repositories/SongRepository.java
+++ b/app/src/main/java/com/stormtales/notevault/data/repositories/SongRepository.java
@ -0,0 +1,86 @@
+package com.stormtales.notevault.data.repositories;
+
+import android.app.Application;
+import android.content.Context;
+import android.os.Handler;
+import android.os.Looper;
+import androidx.lifecycle.LiveData;
+import com.stormtales.notevault.data.MusicDatabase;
+import com.stormtales.notevault.data.dao.SongDao;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.sync.SyncStatus;
+import com.stormtales.notevault.utils.NoteSheetsUtil;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class SongRepository {
+    private SongDao songDao;
+    public SongRepository(Context context) {
+        MusicDatabase database = MusicDatabase.getDatabase(context);
+        songDao = database.getSongTable();
+    }
+    public void insert(Song song, Callback<Long> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            long result = songDao.insert(song);
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(result));
+        });
+    }
+
+    public interface LoadHomeViewModelCallback<T> {
+        void onResult(T result);
+    }
+
+    public void getAllSongs(LoadHomeViewModelCallback<List<Song>> callback) {
+        ExecutorService executorService = Executors.newSingleThreadExecutor();
+        executorService.execute(() -> {
+            List<Song> songs = songDao.getAllSongs();
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(songs));
+        });
+    }
+
+    public void updateSong(Song song) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            songDao.update(song);
+        });
+    }
+
+    public void insertNoteSheets(List<NoteSheet> noteSheets) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            songDao.insert(noteSheets);
+        });
+    }
+
+    public interface Callback<T> {
+        void onResult(T result);
+    }
+
+    public void deleteSong(Song song) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            song.setSyncStatus(SyncStatus.DELETED);
+            songDao.update(song);
+
+            List<NoteSheet> noteSheets = songDao.getNoteSheetsBySong(song.getLocalID());
+            for(NoteSheet noteSheet : noteSheets) {
+                try {
+                    NoteSheetsUtil.deleteNoteSheet(noteSheet.getLocalFileName());
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+            songDao.deleteNoteSheets(noteSheets);
+        });
+    }
+
+    public void getNoteSheetFilesBySongID(int songID, Callback<List<String>> callback) {
+        Executors.newSingleThreadExecutor().execute(()-> {
+            List<String> noteSheetFiles = songDao.getNoteSheetFilesBySongID(songID);
+            callback.onResult(noteSheetFiles);
+        });
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/repositories/SongSyncRepository.java
+++ b/app/src/main/java/com/stormtales/notevault/data/repositories/SongSyncRepository.java
@ -0,0 +1,303 @@
+package com.stormtales.notevault.data.repositories;
+
+import android.content.Context;
+import android.os.Handler;
+import android.os.Looper;
+import androidx.recyclerview.widget.AsyncListUtil;
+import com.stormtales.notevault.data.MusicDatabase;
+import com.stormtales.notevault.data.dao.SongDao;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.sync.SyncStatus;
+import com.stormtales.notevault.network.sync.models.*;
+import com.stormtales.notevault.utils.NoteSheetsUtil;
+
+import java.io.File;
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+public class SongSyncRepository {
+    private SongDao songDao;
+    public SongSyncRepository(Context context) {
+        MusicDatabase database = MusicDatabase.getDatabase(context);
+        songDao = database.getSongTable();
+    }
+
+    public void loadCreatedSongs(LoadDataCallback<List<Song>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<Song> createdSongs = songDao.getSongsBySyncStatus(SyncStatus.CREATED);
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(createdSongs));
+        });
+    }
+
+    public void loadModifiedSongs(LoadDataCallback<Map<Song, List<NoteSheet>>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            Map<Song, List<NoteSheet>> result = new HashMap<>();
+            List<Song> modifiedSongs = songDao.getSongsBySyncStatus(SyncStatus.MODIFIED);
+            for(Song song : modifiedSongs) {
+                List<NoteSheet> noteSheets = songDao.getNoteSheetsBySong(song.getLocalID());
+                result.put(song, noteSheets);
+            }
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(result));
+        });
+    }
+
+    public void loadDeletedSongs(LoadDataCallback<List<Song>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<Song> deletedSongs = songDao.getSongsBySyncStatus(SyncStatus.DELETED);
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(deletedSongs));
+        });
+    }
+
+    public void markCreatedSongsAsSynced(BatchCreateResponse createdSongs) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<Integer> localIDs = createdSongs.getCreateResponses().stream().map(CreateResponse::getLocalID).collect(Collectors.toList());
+            List<Song> requestedSongs = songDao.getSongsByLocalIDs(localIDs);
+
+            for(Song song : requestedSongs) {
+                song.setSyncTime(LocalDateTime.now());
+                song.setSyncStatus(SyncStatus.SYNCED);
+
+                for(CreateResponse createResponse : createdSongs.getCreateResponses()) {
+                    if(createResponse.getLocalID() == song.getLocalID()) {
+                        song.setServerID(createResponse.getServerID());
+                        break;
+                    }
+                }
+            }
+            songDao.updateSongs(requestedSongs);
+        });
+    }
+
+    public void markSongsAsSynced(List<Song> songs) {
+        for(Song song : songs) {
+            song.setSyncStatus(SyncStatus.SYNCED);
+        }
+    }
+
+    public void markModifiedSongsAsSynced(SongModifyBatchResponse modifyBatchResponse) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<String> serverIDs = modifyBatchResponse.getModifiedServerObjects().stream().map(SongModifyResponse::getServerID).collect(Collectors.toList());
+            List<Song> requestedSongs = songDao.getSongsByServerIDs(serverIDs);
+            for(Song song : requestedSongs) {
+                song.setSyncStatus(SyncStatus.SYNCED);
+                song.setSyncTime(LocalDateTime.now());
+
+
+                for(SongModifyResponse modifyResponse : modifyBatchResponse.getModifiedServerObjects()) {
+                    if(modifyResponse.getServerID().equals(song.getServerID())) {
+                        List<NoteSheet> outdatedNoteSheets = songDao.getNoteSheetsByServerFileNames(modifyResponse.getOutdated_note_sheets());
+                        for(NoteSheet noteSheet : outdatedNoteSheets) {
+                            noteSheet.setSyncStatus(SyncStatus.MODIFIED);
+                        }
+                        songDao.updateNoteSheets(outdatedNoteSheets);
+                    }
+                }
+            }
+
+
+            songDao.updateSongs(requestedSongs);
+        });
+    }
+
+    public void markDeletedSongsAsSynced(List<String> remoteDeletedSongs, List<Integer> localDeletedSongs) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            songDao.deleteSongsByServerIDs(remoteDeletedSongs);
+            songDao.deleteSongsByLocalIDs(localDeletedSongs);
+        });
+    }
+
+    public void getNoteSheetFilesBySongIDs(LoadDataCallback<List<NoteSheet>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<NoteSheet> noteSheets = songDao.getNoteSheetsBySyncStatus(SyncStatus.CREATED);
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(noteSheets));
+        });
+    }
+
+    public void markCreatedNoteSheetsAsSynced(List<UploadResponse> uploadResponses) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<String> serverSongIDs = uploadResponses.stream().map(UploadResponse::getServerID).collect(Collectors.toList());
+            List<Integer> localSongIDs = songDao.getLocalSongIDsByServerIDs(serverSongIDs);
+
+            List<NoteSheet> uploadedNoteSheets = songDao.getNoteSheetsBySongIDs(localSongIDs);
+            for(UploadResponse uploadResponse : uploadResponses) {
+                for(NoteSheet noteSheet : uploadedNoteSheets) {
+                    if(new File(noteSheet.getLocalFileName()).getName().equals(uploadResponse.getLocalFile())) {
+                        noteSheet.setServerFileName(uploadResponse.getServerFile());
+                        noteSheet.setSyncStatus(SyncStatus.SYNCED);
+                        break;
+                    }
+                }
+            }
+            songDao.updateNoteSheets(uploadedNoteSheets);
+        });
+    }
+
+    public void loadModifiedNoteSheets(LoadDataCallback<List<NoteSheet>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<NoteSheet> noteSheets = songDao.getNoteSheetsBySyncStatus(SyncStatus.MODIFIED);
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(noteSheets));
+        });
+    }
+
+    public void markModifiedNoteSheetsAsSynced(List<UploadResponse> uploadResponses) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<String> serverFileNames = uploadResponses.stream().map(UploadResponse::getServerFile).collect(Collectors.toList());
+
+
+            List<NoteSheet> noteSheets = songDao.getNoteSheetsByServerFileNames(serverFileNames);
+            for(NoteSheet noteSheet : noteSheets) {
+                noteSheet.setSyncStatus(SyncStatus.SYNCED);
+            }
+            songDao.updateNoteSheets(noteSheets);
+        });
+    }
+
+    public void markSongsAsRemotelyModified(List<String> serverIDs, LoadDataCallback<List<Song>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<Song> songs = songDao.getSongsByServerIDs(serverIDs);
+            List<Song> createdSongs = new ArrayList<>();
+            for(Song song : songs) {
+                song.setSyncStatus(SyncStatus.REMOTE_MODIFIED);
+            }
+
+            for(String serverID : serverIDs) {
+                boolean foundServerSong = false;
+                for(Song song : songs) {
+                    if(song.getServerID().equals(serverID)) {
+                        foundServerSong = true;
+                        break;
+                    }
+                }
+
+                if(!foundServerSong) {
+                    Song song = new Song(serverID);
+                    createdSongs.add(song);
+                }
+            }
+            songDao.updateSongs(songs);
+            songDao.insertSongs(createdSongs);
+            callback.onResult(createdSongs);
+        });
+    }
+
+    public void loadRemotelyModifiedSongs(LoadDataCallback<List<Song>> callback) {
+        Executors.newSingleThreadExecutor().execute(() -> {
+            List<Song> songs = songDao.getSongsBySyncStatus(SyncStatus.REMOTE_MODIFIED);
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(songs));
+        });
+    }
+
+    public void saveRemoteSongs(List<SongModel> remoteSongs, LoadDataCallback<List<NoteSheet>> callback) {
+        Executors.newSingleThreadExecutor().execute(() ->{
+            List<String> serverIDs = remoteSongs.stream().map(SongModel::getServerID).collect(Collectors.toList());
+            List<Song> songs = songDao.getSongsByServerIDs(serverIDs);
+            List<Integer> localSongIDs = songDao.getLocalSongIDsByServerIDs(serverIDs);
+            List<NoteSheet> noteSheets = songDao.getNoteSheetsBySongIDs(localSongIDs);
+
+            List<Song> onlyRemoteExistingSongs = new ArrayList<>();
+            List<NoteSheet> outdatedNoteSheets = new ArrayList<>();
+            List<NoteSheet> onlyRemoteNoteSheets = new ArrayList<>();
+            for(SongModel songModel : remoteSongs) {
+                boolean found = false;
+                for(Song song : songs) {
+                    if(song.getServerID().equals(songModel.getServerID())) {
+                        found = true;
+                        if(!songModel.isDeleted()) {
+                           song.setSyncStatus(SyncStatus.SYNCED);
+                           song.setSyncTime(LocalDateTime.now());
+
+                           song.setTitle(songModel.getTitle());
+                           song.setComposer(songModel.getComposer());
+                           song.setGenre(songModel.getGenre());
+                           song.setYear(songModel.getYear());
+
+                            for(RemotelyModifiedNoteSheetModel remoteNoteSheet : songModel.getNote_sheets()) {
+                                if(noteSheets.isEmpty()) {
+                                    NoteSheet noteSheet = new NoteSheet(song.getLocalID(), remoteNoteSheet.getFilename(), remoteNoteSheet.getServer_filename(), null);
+                                    onlyRemoteNoteSheets.add(noteSheet);
+                                    outdatedNoteSheets.add(noteSheet);
+                                } else {
+                                    boolean foundNoteSheet = false;
+                                    for(NoteSheet noteSheet : noteSheets) {
+                                        if(remoteNoteSheet.getServer_filename().equals(noteSheet.getServerFileName())) {
+                                            foundNoteSheet = true;
+                                            if(!remoteNoteSheet.getHash().equals(noteSheet.getHash())) {
+                                                outdatedNoteSheets.add(noteSheet);
+                                                break;
+                                            }
+                                        }
+                                    }
+
+                                    if(!foundNoteSheet) {
+                                        NoteSheet noteSheet = new NoteSheet(song.getLocalID(), remoteNoteSheet.getFilename(), remoteNoteSheet.getServer_filename(), null);
+                                        onlyRemoteNoteSheets.add(noteSheet);
+                                        outdatedNoteSheets.add(noteSheet);
+                                    }
+                                }
+
+                            }
+
+                        } else {
+                            removeSong(song);
+                        }
+                    }
+                }
+
+                if(!found) {
+                    Song song = new Song(songModel);
+                    onlyRemoteExistingSongs.add(song);
+                }
+            }
+
+            songDao.updateSongs(songs);
+            songDao.insertSongs(onlyRemoteExistingSongs);
+            songDao.insert(onlyRemoteNoteSheets);
+
+            Handler mainHandler = new Handler(Looper.getMainLooper());
+            mainHandler.post(()-> callback.onResult(outdatedNoteSheets));
+        });
+    }
+
+    private void removeSong(Song song) {
+        List<NoteSheet> noteSheets = songDao.getNoteSheetsBySong(song.getLocalID());
+        for(NoteSheet noteSheet : noteSheets) {
+            try {
+                NoteSheetsUtil.deleteNoteSheet(noteSheet.getLocalFileName());
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }
+        songDao.deleteNoteSheets(noteSheets);
+        songDao.deleteSong(song);
+
+    }
+
+
+
+    public void saveUpdatedNoteSheet(String serverFileName, String localFileName, String hash) {
+        Executors.newSingleThreadExecutor().execute(()-> {
+            NoteSheet noteSheet = songDao.getNoteSheetByServerFileName(serverFileName);
+            noteSheet.setHash(hash);
+            noteSheet.setLocalFileName(localFileName);
+            songDao.updateNoteSheet(noteSheet);
+        });
+    }
+
+    public interface LoadDataCallback<T> {
+        void onResult(T result);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/sync/DateConverter.java
+++ b/app/src/main/java/com/stormtales/notevault/data/sync/DateConverter.java
@ -0,0 +1,20 @@
+package com.stormtales.notevault.data.sync;
+
+import androidx.room.TypeConverter;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class DateConverter {
+    // Konvertiere LocalDateTime in String
+    @TypeConverter
+    public static String fromLocalDateTime(LocalDateTime localDateTime) {
+        return localDateTime == null ? null : localDateTime.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+    }
+
+    // Konvertiere String zurück in LocalDateTime
+    @TypeConverter
+    public static LocalDateTime toLocalDateTime(String dateTimeString) {
+        return dateTimeString == null ? null : LocalDateTime.parse(dateTimeString, DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/data/sync/SyncStatus.java
+++ b/app/src/main/java/com/stormtales/notevault/data/sync/SyncStatus.java
@ -0,0 +1,9 @@
+package com.stormtales.notevault.data.sync;
+
+public enum SyncStatus {
+    CREATED,
+    DELETED,
+    MODIFIED,
+    REMOTE_MODIFIED,
+    SYNCED;
+}
--- a/app/src/main/java/com/stormtales/notevault/data/sync/SyncStatusConverter.java
+++ b/app/src/main/java/com/stormtales/notevault/data/sync/SyncStatusConverter.java
@ -0,0 +1,15 @@
+package com.stormtales.notevault.data.sync;
+
+import androidx.room.TypeConverter;
+
+public class SyncStatusConverter {
+    @TypeConverter
+    public static SyncStatus fromInt(int value) {
+        return SyncStatus.values()[value];
+    }
+
+    @TypeConverter
+    public static int toInt(SyncStatus syncStatus) {
+        return syncStatus.ordinal();
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/APICallback.java
+++ b/app/src/main/java/com/stormtales/notevault/network/APICallback.java
@ -0,0 +1,6 @@
+package com.stormtales.notevault.network;
+
+public interface APICallback {
+    void onSuccess();
+    void onError(String error);
+}
--- a/app/src/main/java/com/stormtales/notevault/network/NetworkModule.java
+++ b/app/src/main/java/com/stormtales/notevault/network/NetworkModule.java
@ -0,0 +1,36 @@
+package com.stormtales.notevault.network;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import com.stormtales.notevault.network.auth.AuthInterceptor;
+import com.stormtales.notevault.network.auth.TokenManager;
+import okhttp3.OkHttpClient;
+import okhttp3.logging.HttpLoggingInterceptor;
+import retrofit2.Retrofit;
+import retrofit2.converter.gson.GsonConverterFactory;
+
+public class NetworkModule {
+    private static final String BASE_URL = "https://notevault.fawkes100.de/";
+    private static Retrofit retrofit;
+
+    public static Retrofit getRetrofitInstance(Context context) {
+        if (retrofit == null) {
+            HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
+            loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
+
+            TokenManager tokenManager = new TokenManager(context);
+            OkHttpClient client = new OkHttpClient.Builder()
+                    .addInterceptor(new AuthInterceptor(tokenManager))
+                    .addInterceptor(loggingInterceptor)
+                    .build();
+
+            retrofit = new Retrofit.Builder()
+                    .baseUrl(BASE_URL)
+                    .client(client)
+                    .addConverterFactory(GsonConverterFactory.create())
+                    .build();
+        }
+        return retrofit;
+    }
+
+}
--- a/app/src/main/java/com/stormtales/notevault/network/StatusResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/StatusResponse.java
@ -0,0 +1,14 @@
+package com.stormtales.notevault.network;
+
+public class StatusResponse {
+
+    private String status;
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/AuthAPI.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/AuthAPI.java
@ -0,0 +1,17 @@
+package com.stormtales.notevault.network.auth;
+
+import com.stormtales.notevault.network.StatusResponse;
+import retrofit2.Call;
+import retrofit2.http.Body;
+import retrofit2.http.Headers;
+import retrofit2.http.POST;
+
+public interface AuthAPI {
+
+    @POST("/login/")
+    Call<LoginResponse> login(@Body LoginRequest loginRequest);
+
+    @POST("/register/")
+    @Headers("Content-Type: application/json")
+    Call<StatusResponse> registration(@Body RegisterRequest registerRequest);
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/AuthInterceptor.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/AuthInterceptor.java
@ -0,0 +1,29 @@
+package com.stormtales.notevault.network.auth;
+
+import okhttp3.Interceptor;
+import okhttp3.Request;
+import okhttp3.Response;
+
+import java.io.IOException;
+
+public class AuthInterceptor implements Interceptor {
+    private TokenManager tokenManager;
+
+    public AuthInterceptor(TokenManager tokenManager) {
+        this.tokenManager = tokenManager;
+    }
+
+    @Override
+    public Response intercept(Chain chain) throws IOException {
+        Request originalRequest = chain.request();
+
+        String token = tokenManager.getToken();
+        if (token == null) {
+            return chain.proceed(originalRequest);
+        }
+
+        Request authenticatedRequest = originalRequest.newBuilder()
+                .header("Authorization", "Bearer " + token).build();
+        return chain.proceed(authenticatedRequest);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/AuthService.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/AuthService.java
@ -0,0 +1,87 @@
+package com.stormtales.notevault.network.auth;
+
+import android.content.Context;
+import android.text.TextUtils;
+import com.stormtales.notevault.network.APICallback;
+import com.stormtales.notevault.network.NetworkModule;
+import com.stormtales.notevault.network.StatusResponse;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+public class AuthService {
+
+    private final AuthAPI authAPI;
+    private final TokenManager tokenManager;
+
+    public AuthService(Context context) {
+        this.authAPI = NetworkModule.getRetrofitInstance(context).create(AuthAPI.class);
+        this.tokenManager = new TokenManager(context);
+    }
+
+    public void performLogin(String email, String password, LoginCallback callback) {
+        LoginRequest loginRequest = new LoginRequest(email, password);
+
+        authAPI.login(loginRequest).enqueue(new Callback<LoginResponse>() {
+            @Override
+            public void onResponse(Call<LoginResponse> call, Response<LoginResponse> response) {
+                if (response.isSuccessful() && response.body() != null) {
+                    String token = response.body().getToken();
+                    saveToken(token);
+                    // Erfolgsrückmeldung an den Callback senden
+                    callback.onSuccess(response.body());
+                } else {
+                    // Fehlermeldung an den Callback senden
+                    callback.onError("Login fehlgeschlagen. Überprüfe Benutzername und Passwort.");
+                }
+            }
+
+            @Override
+            public void onFailure(Call<LoginResponse> call, Throwable t) {
+                // Netzwerkfehler an den Callback senden
+                callback.onError("Netzwerkfehler: " + t.getMessage());
+            }
+        });
+    }
+
+    public void performRegistration(String email, String username, String password, APICallback callback) {
+        RegisterRequest registerRequest = new RegisterRequest(username, password, email);
+        authAPI.registration(registerRequest).enqueue(new Callback<StatusResponse>() {
+
+            @Override
+            public void onResponse(Call<StatusResponse> call, Response<StatusResponse> response) {
+                if(response.isSuccessful() && response.body() != null) {
+                    callback.onSuccess();
+                } else {
+                    callback.onError("Registration fehlgeschlagen. Überprüfe Benutzername und Passwort.");
+                }
+            }
+
+            @Override
+            public void onFailure(Call<StatusResponse> call, Throwable throwable) {
+                callback.onError("Netzwerkfehler: " + throwable.getMessage());
+            }
+        });
+    }
+
+    private void saveToken(String token) {
+        tokenManager.saveToken(token);
+    }
+
+    public String getToken() {
+        return tokenManager.getToken();
+    }
+
+    public void logout() {
+        tokenManager.clearToken();
+    }
+
+    public boolean isLoggedIn() {
+        return !TextUtils.isEmpty(tokenManager.getToken());
+    }
+
+    public interface LoginCallback {
+        void onSuccess(LoginResponse loginResponse);
+        void onError(String error);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/LoginRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/LoginRequest.java
@ -0,0 +1,11 @@
+package com.stormtales.notevault.network.auth;
+
+public class LoginRequest {
+    private String email;
+    private String password;
+
+    public LoginRequest(String email, String password) {
+        this.email = email;
+        this.password = password;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/LoginResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/LoginResponse.java
@ -0,0 +1,22 @@
+package com.stormtales.notevault.network.auth;
+
+public class LoginResponse {
+    private String token;
+    private String username;
+
+    public String getToken() {
+        return token;
+    }
+
+    public void setToken(String token) {
+        this.token = token;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/RegisterRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/RegisterRequest.java
@ -0,0 +1,14 @@
+package com.stormtales.notevault.network.auth;
+
+public class RegisterRequest {
+    private String username;
+    private String email;
+    private String password;
+
+    public RegisterRequest(String username, String password, String email) {
+        this.username = username;
+        this.password = password;
+        this.email = email;
+    }
+
+}
--- a/app/src/main/java/com/stormtales/notevault/network/auth/TokenManager.java
+++ b/app/src/main/java/com/stormtales/notevault/network/auth/TokenManager.java
@ -0,0 +1,31 @@
+package com.stormtales.notevault.network.auth;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+public class TokenManager {
+    private static final String PREF_NAME = "app_preferences";
+    private static final String KEY_TOKEN = "jwt_token";
+
+    private SharedPreferences sharedPreferences;
+
+    public TokenManager(Context context) {
+        sharedPreferences = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+    }
+
+    public void saveToken(String token) {
+        SharedPreferences.Editor editor = sharedPreferences.edit();
+        editor.putString(KEY_TOKEN, token);
+        editor.apply();
+    }
+
+    public String getToken() {
+        return sharedPreferences.getString(KEY_TOKEN, null);
+    }
+
+    public void clearToken() {
+        SharedPreferences.Editor editor = sharedPreferences.edit();
+        editor.remove(KEY_TOKEN);
+        editor.apply();
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/SongSyncAPI.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/SongSyncAPI.java
@ -0,0 +1,45 @@
+package com.stormtales.notevault.network.sync;
+
+import com.stormtales.notevault.network.auth.LoginRequest;
+import com.stormtales.notevault.network.auth.LoginResponse;
+import com.stormtales.notevault.network.sync.models.*;
+import okhttp3.MultipartBody;
+import okhttp3.RequestBody;
+import okhttp3.ResponseBody;
+import retrofit2.Call;
+import retrofit2.http.*;
+
+import java.time.LocalDateTime;
+
+public interface SongSyncAPI {
+
+    @POST("/sync/songs/create")
+    Call<BatchCreateResponse> syncCreatedSongs(@Body SongCreateBatchRequest songCreateBatchRequest);
+
+    @POST("/sync/songs/modify")
+    Call<SongModifyBatchResponse> syncModifiedSongs(@Body SongModifyBatchRequest songModifyBatchRequest);
+
+    @POST("/sync/songs/delete")
+    Call<BatchModifyResponse> syncDeletedSongs(@Body SongBatchDeleteRequest songBatchDeleteRequest);
+
+    @Multipart
+    @POST("/sync/songs/note_sheet/upload")
+    Call<UploadResponse> uploadNoteSheet(@Part("serverID")RequestBody serverID, @Part("fileName") RequestBody fileName, @Part MultipartBody.Part image);
+
+    @Multipart
+    @POST("/sync/songs/note_sheet/update")
+    Call<UploadResponse> updateNoteSheet(@Part("server_filename") RequestBody server_filename, @Part MultipartBody.Part image);
+
+    @GET("/sync/songs/fetch")
+    Call<FetchResponse> fetchRemoteModifiedSongs(@Query(value = "last_client_sync") String last_client_sync);
+
+    @GET("/sync/songs/get/")
+    Call<SongModel> fetchRemotelyModifiedSongData(@Query(value = "songID") String songID);
+
+    @GET("/sync/songs/get/notesheet/")
+    Call<ResponseBody> downloadNotesheet(@Query("server_filename") String server_filename);
+
+    @Multipart
+    @POST("/ai/regognize/title")
+    Call<AIRecognizedSong> recognizeTitle(@Part MultipartBody.Part image);
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/SongSyncModule.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/SongSyncModule.java
@ -0,0 +1,154 @@
+package com.stormtales.notevault.network.sync;
+
+import android.content.Context;
+import android.net.Uri;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.repositories.SongRepository;
+import com.stormtales.notevault.data.repositories.SongSyncRepository;
+import com.stormtales.notevault.network.sync.models.*;
+import com.stormtales.notevault.ui.gallery.GalleryViewModel;
+import com.stormtales.notevault.utils.NoteSheetsUtil;
+import com.stormtales.notevault.utils.Tupel;
+
+import java.io.File;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class SongSyncModule {
+    private SongRepository songRepository;
+    private SongSyncRepository songSyncRepository;
+    private SongSyncService songSyncService;
+    private GalleryViewModel syncViewModel;
+    private Context context;
+
+    public SongSyncModule(Context context, GalleryViewModel syncViewModel) {
+        this.songRepository = new SongRepository(context);
+        this.songSyncRepository = new SongSyncRepository(context);
+        this.songSyncService = new SongSyncService(context);
+        this.syncViewModel = syncViewModel;
+        this.context = context;
+    }
+
+    public void syncCreatedSongs() {
+        songSyncRepository.loadCreatedSongs(result -> {
+            songSyncService.syncCreatedSongs(result, response -> {
+                songSyncRepository.markCreatedSongsAsSynced(response);
+                if(response.getCreateResponses().isEmpty()) {
+                    syncViewModel.finishCreateSongSyncing();
+                } else {
+                    uploadCreatedNoteSheets(result, response);
+                }
+            });
+        });
+    }
+
+    public void uploadCreatedNoteSheets(List<Song> result, BatchCreateResponse response) {
+        List<Integer> songIDs = result.stream().map(Song::getLocalID).collect(Collectors.toList());
+        songSyncRepository.getNoteSheetFilesBySongIDs(noteSheets -> {
+            songSyncService.uploadNoteSheetsOfCreatedSongs(noteSheets, response, uploadResponses -> {
+                songSyncRepository.markCreatedNoteSheetsAsSynced(uploadResponses);
+                syncViewModel.finishCreateSongSyncing();
+            });
+        });
+    }
+
+    public void syncModifiedSongs() {
+        songSyncRepository.loadModifiedSongs(result -> {
+            songSyncService.syncModifiedSongs(result, (FinishSongSyncingCallback<SongModifyBatchResponse>) response -> {
+                songSyncRepository.markModifiedSongsAsSynced(response);
+                uploadModifiedNoteSheets();
+            });
+        });
+    }
+
+    public void uploadModifiedNoteSheets() {
+        songSyncRepository.loadModifiedNoteSheets(modifiedNoteSheets -> {
+            if(modifiedNoteSheets.isEmpty()) {
+                syncViewModel.finishModifiedSongSyncinc();
+            } else {
+                songSyncService.uploadModifiedNoteSheets(modifiedNoteSheets, new SongSyncService.UploadNoteSheetCallback() {
+                    @Override
+                    public void finishUploadNoteSheets(List<UploadResponse> uploadResponses) {
+                        songSyncRepository.markModifiedNoteSheetsAsSynced(uploadResponses);
+                        syncViewModel.finishModifiedSongSyncinc();
+                    }
+                });
+            }
+        });
+    }
+
+    public void syncDeletedSongs() {
+        songSyncRepository.loadDeletedSongs(result -> {
+            songSyncService.syncDeletedSong(result, (remoteDeletedSongs, localDeletedSongs) -> {
+                songSyncRepository.markDeletedSongsAsSynced(remoteDeletedSongs, localDeletedSongs);
+                syncViewModel.finishDeleteSongSyncinc();
+            });
+        });
+    }
+
+    public void fetchRemoteModifiedSongs() {
+        //Todo: Determine Last Client Sync; for testing use LocalDateTime.MIN
+        songSyncService.fetchRemoteModifiedSongs(LocalDateTime.now().minusDays(35), new SongSyncRepository.LoadDataCallback<FetchResponse>() {
+            @Override
+            public void onResult(FetchResponse result) {
+                songSyncRepository.markSongsAsRemotelyModified(result.getServerIDs(), createdSongs -> {
+                    getRemotelyModifiedSongData(createdSongs);
+                });
+
+            }
+        });
+    }
+
+    public void getRemotelyModifiedSongData(List<Song> freshlyCreatedSongs) {
+        songSyncRepository.loadRemotelyModifiedSongs(songs -> {
+            for(Song song : freshlyCreatedSongs) {
+                boolean freshlyCreatedSongFound = false;
+                for(Song s : songs) {
+                    if(s.getServerID().equals(song.getServerID())) {
+                        freshlyCreatedSongFound = true;
+                        break;
+                    }
+                }
+                if(!freshlyCreatedSongFound) {
+                    songs.add(song);
+                }
+
+            }
+            if(songs.isEmpty()) {
+                syncViewModel.finishFetching();
+            } else {
+                songSyncService.getRemotelyModifiedSongData(songs, remoteSongs -> {
+                    if(remoteSongs.isEmpty()) {
+                        syncViewModel.finishFetching();
+                    } else {
+                        songSyncRepository.saveRemoteSongs(remoteSongs, this::downloadNoteSheets);
+                    }
+                });
+            }
+
+        });
+    }
+
+    public void downloadNoteSheets(List<NoteSheet> noteSheets) {
+        for(NoteSheet noteSheet : noteSheets) {
+            songSyncService.downloadNoteSheet(noteSheet, responseBody -> {
+                String localFilename = noteSheet.getServerFileName().substring(36);
+
+                Tupel<String, String> result = NoteSheetsUtil.saveImageFromServer(responseBody, context.getFilesDir());
+                songSyncRepository.saveUpdatedNoteSheet(noteSheet.getServerFileName(), result.getValue00(), result.getValue01());
+            });
+        }
+        syncViewModel.finishFetching();
+    }
+
+    public interface FinishSongCreateSyncingCallback {
+        void finishSongSyncing(BatchCreateResponse response);
+    }
+
+    public interface FinishSongSyncingCallback<T> {
+        void finishSongSyncing(T response);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/SongSyncService.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/SongSyncService.java
@ -0,0 +1,246 @@
+package com.stormtales.notevault.network.sync;
+
+import android.content.Context;
+import android.util.Log;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.repositories.SongSyncRepository;
+import com.stormtales.notevault.network.NetworkModule;
+import com.stormtales.notevault.network.auth.AuthAPI;
+import com.stormtales.notevault.network.sync.models.*;
+import com.stormtales.notevault.ui.gallery.GalleryViewModel;
+import okhttp3.MediaType;
+import okhttp3.MultipartBody;
+import okhttp3.RequestBody;
+import okhttp3.ResponseBody;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+import java.io.File;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class SongSyncService {
+    private final SongSyncAPI songSyncAPI;
+    private GalleryViewModel syncStatusViewModel;
+
+    public SongSyncService(Context context) {
+        songSyncAPI = NetworkModule.getRetrofitInstance(context).create(SongSyncAPI.class);
+    }
+
+    public void syncCreatedSongs(List<Song> songs, SongSyncModule.FinishSongCreateSyncingCallback callback) {
+        List<SongCreateRequest> createRequests = new ArrayList<>();
+        for(Song song : songs) {
+            createRequests.add(new SongCreateRequest(song));
+        }
+        SongCreateBatchRequest songCreateBatchRequest = new SongCreateBatchRequest(createRequests);
+        songSyncAPI.syncCreatedSongs(songCreateBatchRequest).enqueue(new Callback<BatchCreateResponse>() {
+            @Override
+            public void onResponse(Call<BatchCreateResponse> call, Response<BatchCreateResponse> response) {
+                callback.finishSongSyncing(response.body());
+            }
+
+            @Override
+            public void onFailure(Call<BatchCreateResponse> call, Throwable throwable) {
+
+            }
+        });
+    }
+
+    public void uploadNoteSheetsOfCreatedSongs(List<NoteSheet> noteSheets, BatchCreateResponse batchCreateResponse, UploadNoteSheetCallback callback) {
+        List<UploadResponse> uploadResponses = new ArrayList<>();
+        for(CreateResponse createResponse : batchCreateResponse.getCreateResponses()) {
+            for(NoteSheet noteSheet : noteSheets) {
+                if(noteSheet.getSongID() == createResponse.getLocalID()) {
+                    File imageFile = new File(noteSheet.getLocalFileName());
+
+                    RequestBody serverID = RequestBody.create(MediaType.parse("text/plain"), createResponse.getServerID());
+                    RequestBody fileName = RequestBody.create(MediaType.parse("text/plain"), imageFile.getName());
+
+                    RequestBody requestFile = RequestBody.create(MediaType.parse("image/**"), new File(noteSheet.getLocalFileName()));
+                    MultipartBody.Part image = MultipartBody.Part.createFormData("image", noteSheet.getLocalFileName(), requestFile);
+
+                    songSyncAPI.uploadNoteSheet(serverID, fileName, image).enqueue(new Callback<UploadResponse>() {
+                        @Override
+                        public void onResponse(Call<UploadResponse> call, Response<UploadResponse> response) {
+                            if(response.isSuccessful() && response.body() != null) {
+                                uploadResponses.add(response.body());
+                                if(uploadResponses.size() == noteSheets.size()) {
+                                    callback.finishUploadNoteSheets(uploadResponses);
+                                }
+                            }
+                        }
+
+                        @Override
+                        public void onFailure(Call<UploadResponse> call, Throwable throwable) {
+
+                        }
+                    });
+                }
+            }
+        }
+    }
+
+    public void syncModifiedSongs(Map<Song, List<NoteSheet>> songs, SongSyncModule.FinishSongSyncingCallback<SongModifyBatchResponse> callback) {
+        List<SongModifyRequest> modifyRequests = new ArrayList<>();
+        for(Map.Entry<Song, List<NoteSheet>> entry: songs.entrySet()) {
+            modifyRequests.add(new SongModifyRequest(entry.getKey(), entry.getValue()));
+        }
+        SongModifyBatchRequest songModifyBatchRequest = new SongModifyBatchRequest(modifyRequests);
+        songSyncAPI.syncModifiedSongs(songModifyBatchRequest).enqueue(new Callback<SongModifyBatchResponse>() {
+            @Override
+            public void onResponse(Call<SongModifyBatchResponse> call, Response<SongModifyBatchResponse> response) {
+                callback.finishSongSyncing(response.body());
+            }
+
+            @Override
+            public void onFailure(Call<SongModifyBatchResponse> call, Throwable throwable) {
+
+            }
+        });
+    }
+
+    public void syncDeletedSong(List<Song> songs, SyncDeletedSongsCallback callback) {
+        List<String> deleteRequests = new ArrayList<>();
+        List<Integer> deletedNotSyncedSongs = new ArrayList<>();
+        for(Song song : songs) {
+            if(song.getServerID() == null) {
+                deletedNotSyncedSongs.add(song.getLocalID());
+            } else {
+                deleteRequests.add(song.getServerID());
+            }
+        }
+
+        SongBatchDeleteRequest songBatchDeleteRequest = new SongBatchDeleteRequest(deleteRequests);
+        songSyncAPI.syncDeletedSongs(songBatchDeleteRequest).enqueue(new Callback<BatchModifyResponse>() {
+            @Override
+            public void onResponse(Call<BatchModifyResponse> call, Response<BatchModifyResponse> response) {
+                if(response.isSuccessful() && response.body() != null) {
+                    callback.finishSongSyncing(response.body().getModifiedServerObjects(), deletedNotSyncedSongs);
+                }
+            }
+
+            @Override
+            public void onFailure(Call<BatchModifyResponse> call, Throwable throwable) {
+
+            }
+        });
+    }
+
+    public void uploadModifiedNoteSheets(List<NoteSheet> modifiedNoteSheets, UploadNoteSheetCallback callback) {
+        List<UploadResponse> uploadResponses = new ArrayList<>();
+        for(NoteSheet noteSheet : modifiedNoteSheets) {
+            RequestBody server_filename = RequestBody.create(MediaType.parse("text/plain"), noteSheet.getServerFileName());
+
+            RequestBody requestFile = RequestBody.create(MediaType.parse("image/**"), new File(noteSheet.getLocalFileName()));
+            MultipartBody.Part image = MultipartBody.Part.createFormData("image", noteSheet.getLocalFileName(), requestFile);
+
+            songSyncAPI.updateNoteSheet(server_filename, image).enqueue(new Callback<UploadResponse>() {
+                @Override
+                public void onResponse(Call<UploadResponse> call, Response<UploadResponse> response) {
+                    if(response.isSuccessful() && response.body() != null) {
+                        uploadResponses.add(response.body());
+                        if(uploadResponses.size() == modifiedNoteSheets.size()) {
+                            callback.finishUploadNoteSheets(uploadResponses);
+                        }
+                    } else {
+                        Log.d("SongSyncService", "Something went wrong");
+                    }
+                }
+
+                @Override
+                public void onFailure(Call<UploadResponse> call, Throwable throwable) {
+                    Log.e("SongSyncService", "Upload failed: " + throwable.getMessage(), throwable);
+                }
+            });
+        }
+    }
+
+    public void fetchRemoteModifiedSongs(LocalDateTime lastClientSync, SongSyncRepository.LoadDataCallback<FetchResponse> callback) {
+        String formattedTime = lastClientSync.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME);
+        songSyncAPI.fetchRemoteModifiedSongs(formattedTime).enqueue(new Callback<FetchResponse>() {
+            @Override
+            public void onResponse(Call<FetchResponse> call, Response<FetchResponse> response) {
+                if(response.isSuccessful() && response.body() != null) {
+                    callback.onResult(response.body());
+                }
+            }
+
+            @Override
+            public void onFailure(Call<FetchResponse> call, Throwable throwable) {
+                Log.d("SongSyncService", "Fetch failed: " + throwable.getMessage(), throwable);
+            }
+        });
+    }
+
+    public void getRemotelyModifiedSongData(List<Song> remotelyModifiedSongs, SongSyncRepository.LoadDataCallback<List<SongModel>> callback) {
+        List<SongModel> songModels = new ArrayList<>();
+        for(Song song : remotelyModifiedSongs) {
+            songSyncAPI.fetchRemotelyModifiedSongData(song.getServerID()).enqueue(new Callback<SongModel>() {
+                @Override
+                public void onResponse(Call<SongModel> call, Response<SongModel> response) {
+                    if(response.isSuccessful() && response.body() != null) {
+                        songModels.add(response.body());
+                        if(songModels.size() == remotelyModifiedSongs.size()) {
+                            callback.onResult(songModels);
+                        }
+                    }
+                }
+
+                @Override
+                public void onFailure(Call<SongModel> call, Throwable throwable) {
+                    Log.d("SongSyncService", "Fetch failed: " + throwable.getMessage(), throwable);
+                }
+            });
+        }
+    }
+
+    public void downloadNoteSheet(NoteSheet noteSheet, SongSyncRepository.LoadDataCallback<ResponseBody> callback) {
+        songSyncAPI.downloadNotesheet(noteSheet.getServerFileName()).enqueue(new Callback<ResponseBody>() {
+            @Override
+            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
+                if(response.isSuccessful() && response.body() != null) {
+                    callback.onResult(response.body());
+                }
+            }
+
+            @Override
+            public void onFailure(Call<ResponseBody> call, Throwable throwable) {
+                Log.d("SongSyncService", "Download failed: " + throwable.getMessage(), throwable);
+            }
+        });
+    }
+
+    public void recognizeTitle(String firstNoteSheet, RecognizedSongCallback callback) {
+        RequestBody requestFile = RequestBody.create(MediaType.parse("image/jpeg"), new File(firstNoteSheet));
+        MultipartBody.Part image = MultipartBody.Part.createFormData("image", firstNoteSheet, requestFile);
+        songSyncAPI.recognizeTitle(image).enqueue(new Callback<AIRecognizedSong>() {
+            @Override
+            public void onResponse(Call<AIRecognizedSong> call, Response<AIRecognizedSong> response) {
+                callback.onRecognizedSong(response.body());
+            }
+
+            @Override
+            public void onFailure(Call<AIRecognizedSong> call, Throwable throwable) {
+                Log.d("SongSyncService", "Recognition failed: " + throwable.getMessage(), throwable);
+            }
+        });
+    }
+
+
+    public interface SyncDeletedSongsCallback {
+        void finishSongSyncing(List<String> remoteDeletedSongs, List<Integer> localDeletedSongs);
+    }
+
+    public interface UploadNoteSheetCallback {
+        void finishUploadNoteSheets(List<UploadResponse> uploadResponses);
+    }
+
+    public interface RecognizedSongCallback {
+        void onRecognizedSong(AIRecognizedSong aiRecognizedSong);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/AIRecognizedSong.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/AIRecognizedSong.java
@ -0,0 +1,40 @@
+package com.stormtales.notevault.network.sync.models;
+
+public class AIRecognizedSong {
+    private String title;
+    private int year;
+    private String composer;
+    private String description;
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+
+    public String getComposer() {
+        return composer;
+    }
+
+    public void setComposer(String composer) {
+        this.composer = composer;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/BatchCreateResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/BatchCreateResponse.java
@ -0,0 +1,15 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class BatchCreateResponse {
+    private List<CreateResponse> createResponses;
+
+    public List<CreateResponse> getCreateResponses() {
+        return createResponses;
+    }
+
+    public void setCreateResponses(List<CreateResponse> createResponses) {
+        this.createResponses = createResponses;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/BatchModifyResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/BatchModifyResponse.java
@ -0,0 +1,15 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class BatchModifyResponse {
+    private List<String> modifiedServerObjects;
+
+    public List<String> getModifiedServerObjects() {
+        return modifiedServerObjects;
+    }
+
+    public void setModifiedServerObjects(List<String> modifiedServerObjects) {
+        this.modifiedServerObjects = modifiedServerObjects;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/CreateResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/CreateResponse.java
@ -0,0 +1,22 @@
+package com.stormtales.notevault.network.sync.models;
+
+public class CreateResponse {
+    private int localID;
+    private String serverID;
+
+    public int getLocalID() {
+        return localID;
+    }
+
+    public void setLocalID(int localID) {
+        this.localID = localID;
+    }
+
+    public String getServerID() {
+        return serverID;
+    }
+
+    public void setServerID(String serverID) {
+        this.serverID = serverID;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/FetchResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/FetchResponse.java
@ -0,0 +1,15 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class FetchResponse {
+    private List<String> serverIDs;
+
+    public List<String> getServerIDs() {
+        return serverIDs;
+    }
+
+    public void setServerIDs(List<String> serverIDs) {
+        this.serverIDs = serverIDs;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/NoteSheetModifyRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/NoteSheetModifyRequest.java
@ -0,0 +1,27 @@
+package com.stormtales.notevault.network.sync.models;
+
+public class NoteSheetModifyRequest {
+    private String serverFileName;
+    private String clientHash;
+
+    public NoteSheetModifyRequest(String serverFileName, String clientHash) {
+        this.serverFileName = serverFileName;
+        this.clientHash = clientHash;
+    }
+
+    public String getServerFileName() {
+        return serverFileName;
+    }
+
+    public void setServerFileName(String serverFileName) {
+        this.serverFileName = serverFileName;
+    }
+
+    public String getClientHash() {
+        return clientHash;
+    }
+
+    public void setClientHash(String clientHash) {
+        this.clientHash = clientHash;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/RemotelyModifiedNoteSheetModel.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/RemotelyModifiedNoteSheetModel.java
@ -0,0 +1,31 @@
+package com.stormtales.notevault.network.sync.models;
+
+public class RemotelyModifiedNoteSheetModel {
+    private String filename;
+    private String server_filename;
+    private String hash;
+
+    public String getFilename() {
+        return filename;
+    }
+
+    public void setFilename(String filename) {
+        this.filename = filename;
+    }
+
+    public String getServer_filename() {
+        return server_filename;
+    }
+
+    public void setServer_filename(String server_filename) {
+        this.server_filename = server_filename;
+    }
+
+    public String getHash() {
+        return hash;
+    }
+
+    public void setHash(String hash) {
+        this.hash = hash;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongBatchDeleteRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongBatchDeleteRequest.java
@ -0,0 +1,19 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class SongBatchDeleteRequest {
+    private List<String> songs;
+
+    public SongBatchDeleteRequest(List<String> songs) {
+        this.songs = songs;
+    }
+
+    public List<String> getSongs() {
+        return songs;
+    }
+
+    public void setSongs(List<String> songs) {
+        this.songs = songs;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongCreateBatchRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongCreateBatchRequest.java
@ -0,0 +1,20 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class SongCreateBatchRequest {
+
+    private List<SongCreateRequest> songs;
+
+    public SongCreateBatchRequest(List<SongCreateRequest> songs) {
+        this.songs = songs;
+    }
+
+    public List<SongCreateRequest> getSongs() {
+        return songs;
+    }
+
+    public void setSongs(List<SongCreateRequest> songs) {
+        this.songs = songs;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongCreateRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongCreateRequest.java
@ -0,0 +1,67 @@
+package com.stormtales.notevault.network.sync.models;
+
+import com.stormtales.notevault.data.entities.Song;
+
+public class SongCreateRequest {
+    private int localID;
+    private String title;
+    private String composer;
+    private String genre;
+    private int year;
+
+    public SongCreateRequest(int localID, String title, String composer, String genre, int year) {
+        this.localID = localID;
+        this.title = title;
+        this.composer = composer;
+        this.genre = genre;
+        this.year = year;
+    }
+
+    public SongCreateRequest(Song song) {
+        this.localID = song.getLocalID();
+        this.title = song.getTitle();
+        this.composer = song.getComposer();
+        this.genre = song.getGenre();
+        this.year = song.getYear();
+    }
+
+    public int getLocalID() {
+        return localID;
+    }
+
+    public void setLocalID(int localID) {
+        this.localID = localID;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getComposer() {
+        return composer;
+    }
+
+    public void setComposer(String composer) {
+        this.composer = composer;
+    }
+
+    public String getGenre() {
+        return genre;
+    }
+
+    public void setGenre(String genre) {
+        this.genre = genre;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModel.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModel.java
@ -0,0 +1,69 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class SongModel {
+    private String serverID;
+    private String title;
+    private String composer;
+    private String genre;
+    private int year;
+    private List<RemotelyModifiedNoteSheetModel> note_sheets;
+    private boolean deleted;
+
+    public String getServerID() {
+        return serverID;
+    }
+
+    public void setServerID(String serverID) {
+        this.serverID = serverID;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getComposer() {
+        return composer;
+    }
+
+    public void setComposer(String composer) {
+        this.composer = composer;
+    }
+
+    public String getGenre() {
+        return genre;
+    }
+
+    public void setGenre(String genre) {
+        this.genre = genre;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+
+    public List<RemotelyModifiedNoteSheetModel> getNote_sheets() {
+        return note_sheets;
+    }
+
+    public void setNote_sheets(List<RemotelyModifiedNoteSheetModel> note_sheets) {
+        this.note_sheets = note_sheets;
+    }
+
+    public boolean isDeleted() {
+        return deleted;
+    }
+
+    public void setDeleted(boolean deleted) {
+        this.deleted = deleted;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyBatchRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyBatchRequest.java
@ -0,0 +1,19 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class SongModifyBatchRequest {
+    private List<SongModifyRequest> songs;
+
+    public SongModifyBatchRequest(List<SongModifyRequest> songs) {
+        this.songs = songs;
+    }
+
+    public List<SongModifyRequest> getSongs() {
+        return songs;
+    }
+
+    public void setSongs(List<SongModifyRequest> songs) {
+        this.songs = songs;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyBatchResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyBatchResponse.java
@ -0,0 +1,16 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class SongModifyBatchResponse {
+
+    private List<SongModifyResponse> modifiedServerObjects;
+
+    public List<SongModifyResponse> getModifiedServerObjects() {
+        return modifiedServerObjects;
+    }
+
+    public void setModifiedServerObjects(List<SongModifyResponse> modifiedServerObjects) {
+        this.modifiedServerObjects = modifiedServerObjects;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyRequest.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyRequest.java
@ -0,0 +1,82 @@
+package com.stormtales.notevault.network.sync.models;
+
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class SongModifyRequest {
+
+    private String serverID;
+    private String title;
+    private String composer;
+    private String genre;
+    private int year;
+    private List<NoteSheetModifyRequest> noteSheets;
+
+    public SongModifyRequest(String serverID, String title, String composer, String genre, int year) {
+        this.serverID = serverID;
+        this.title = title;
+        this.composer = composer;
+        this.genre = genre;
+        this.year = year;
+    }
+
+    public SongModifyRequest(Song song, List<NoteSheet> noteSheets) {
+        this.serverID = song.getServerID();
+        this.title = song.getTitle();
+        this.composer = song.getComposer();
+        this.genre = song.getGenre();
+        this.year = song.getYear();
+        this.noteSheets = noteSheets.stream().map(noteSheet -> new NoteSheetModifyRequest(noteSheet.getServerFileName(), noteSheet.getHash())).collect(Collectors.toList());
+    }
+
+    public String getServerID() {
+        return serverID;
+    }
+
+    public void setServerID(String serverID) {
+        this.serverID = serverID;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getComposer() {
+        return composer;
+    }
+
+    public void setComposer(String composer) {
+        this.composer = composer;
+    }
+
+    public String getGenre() {
+        return genre;
+    }
+
+    public void setGenre(String genre) {
+        this.genre = genre;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+
+    public List<NoteSheetModifyRequest> getNoteSheets() {
+        return noteSheets;
+    }
+
+    public void setNoteSheets(List<NoteSheetModifyRequest> noteSheets) {
+        this.noteSheets = noteSheets;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/SongModifyResponse.java
@ -0,0 +1,25 @@
+package com.stormtales.notevault.network.sync.models;
+
+import java.util.List;
+
+public class SongModifyResponse {
+
+    private String serverID;
+    private List<String> outdated_note_sheets;
+
+    public List<String> getOutdated_note_sheets() {
+        return outdated_note_sheets;
+    }
+
+    public void setOutdated_note_sheets(List<String> outdated_note_sheets) {
+        this.outdated_note_sheets = outdated_note_sheets;
+    }
+
+    public String getServerID() {
+        return serverID;
+    }
+
+    public void setServerID(String serverID) {
+        this.serverID = serverID;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/network/sync/models/UploadResponse.java
+++ b/app/src/main/java/com/stormtales/notevault/network/sync/models/UploadResponse.java
@ -0,0 +1,31 @@
+package com.stormtales.notevault.network.sync.models;
+
+public class UploadResponse {
+    private String serverID;
+    private String localFile;
+    private String serverFile;
+
+    public String getServerID() {
+        return serverID;
+    }
+
+    public void setServerID(String serverID) {
+        this.serverID = serverID;
+    }
+
+    public String getLocalFile() {
+        return localFile;
+    }
+
+    public void setLocalFile(String localFile) {
+        this.localFile = localFile;
+    }
+
+    public String getServerFile() {
+        return serverFile;
+    }
+
+    public void setServerFile(String serverFile) {
+        this.serverFile = serverFile;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/gallery/GalleryFragment.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/gallery/GalleryFragment.java
@ -0,0 +1,124 @@
+package com.stormtales.notevault.ui.gallery;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Button;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
+import com.stormtales.notevault.data.repositories.SongRepository;
+import com.stormtales.notevault.databinding.FragmentGalleryBinding;
+import com.stormtales.notevault.network.sync.SongSyncModule;
+import com.stormtales.notevault.network.sync.SongSyncService;
+
+
+public class GalleryFragment extends Fragment {
+
+    GalleryViewModel galleryViewModel;
+    private FragmentGalleryBinding binding;
+    private ProgressBar progress_sync_created_songs;
+    private Button sync_created_songs_btn;
+    private ProgressBar progress_sync_modified_songs;
+    private Button sync_modified_songs_btn;
+    private ProgressBar progress_sync_deleted_songs;
+    private Button sync_deleted_songs_btn;
+
+    private ProgressBar progress_fetching_songs;
+    private Button sync_fetching_songs_btn;
+
+
+    public View onCreateView(@NonNull LayoutInflater inflater,
+                             ViewGroup container, Bundle savedInstanceState) {
+        galleryViewModel = new ViewModelProvider(this).get(GalleryViewModel.class);
+
+        binding = FragmentGalleryBinding.inflate(inflater, container, false);
+        View root = binding.getRoot();
+
+        progress_sync_created_songs = binding.progressSyncCreatedSongs;
+        sync_created_songs_btn = binding.syncCreatedBtn;
+        sync_created_songs_btn.setOnClickListener(v -> onSyncCreatedSongs());
+
+        progress_sync_modified_songs = binding.progressSyncModifiedSongs;
+        sync_modified_songs_btn = binding.syncModifiedBtn;
+        sync_modified_songs_btn.setOnClickListener(v -> onSyncModifiedSogs());
+
+        progress_sync_deleted_songs = binding.progressSyncDeletedSongs;
+        sync_deleted_songs_btn = binding.syncDeletedBtn;
+        sync_deleted_songs_btn.setOnClickListener(v -> onSyncDeletedSongs());
+
+        progress_fetching_songs = binding.progressFetchSongs;
+        sync_fetching_songs_btn = binding.fetchSongsBtn;
+        sync_fetching_songs_btn.setOnClickListener(v -> onFetchRemoteModifiedSongs());
+
+        galleryViewModel.setSongSyncModule(new SongSyncModule(getContext(), galleryViewModel));
+
+        galleryViewModel.getIsCreatedSongSyncing().observe(getViewLifecycleOwner(), isCreatedSyncinc -> {
+            if(isCreatedSyncinc) {
+                progress_sync_created_songs.setIndeterminate(true);
+                sync_created_songs_btn.setEnabled(false);
+            } else {
+                progress_sync_created_songs.setIndeterminate(false);
+                sync_created_songs_btn.setEnabled(true);
+            }
+        });
+
+        galleryViewModel.getIsModifiedSongSyncing().observe(getViewLifecycleOwner(), isModifiedSyncinc -> {
+            if(isModifiedSyncinc) {
+                progress_sync_modified_songs.setIndeterminate(true);
+                sync_modified_songs_btn.setEnabled(false);
+            } else {
+                progress_sync_modified_songs.setIndeterminate(false);
+                sync_modified_songs_btn.setEnabled(true);
+            }
+        });
+
+        galleryViewModel.getIsDeletedSongSyncing().observe(getViewLifecycleOwner(), isDeletedSyncinc -> {
+            if(isDeletedSyncinc) {
+                progress_sync_deleted_songs.setIndeterminate(true);
+                sync_deleted_songs_btn.setEnabled(false);
+            } else {
+                progress_sync_deleted_songs.setIndeterminate(false);
+                sync_deleted_songs_btn.setEnabled(true);
+            }
+        });
+
+        galleryViewModel.getIsFetchingActive().observe(getViewLifecycleOwner(), isFetchingActiveSyncinc -> {
+            if(isFetchingActiveSyncinc) {
+                progress_fetching_songs.setIndeterminate(true);
+                sync_fetching_songs_btn.setEnabled(false);
+            } else {
+                progress_fetching_songs.setIndeterminate(false);
+                sync_fetching_songs_btn.setEnabled(true);
+            }
+        });
+        return root;
+    }
+
+    private void onFetchRemoteModifiedSongs() {
+        galleryViewModel.startFetchingActive();
+    }
+
+    private void onSyncDeletedSongs() {
+        galleryViewModel.startDeletedSongSyncing();
+    }
+
+
+    @Override
+    public void onDestroyView() {
+        super.onDestroyView();
+        binding = null;
+    }
+
+    private void onSyncCreatedSongs() {
+        galleryViewModel.startCreateSongSyncing();
+    }
+
+
+    private void onSyncModifiedSogs() {
+        galleryViewModel.startModifiedSongSyncinc();
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/gallery/GalleryViewModel.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/gallery/GalleryViewModel.java
@ -0,0 +1,92 @@
+package com.stormtales.notevault.ui.gallery;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+import com.stormtales.notevault.data.repositories.SongRepository;
+import com.stormtales.notevault.network.sync.SongSyncModule;
+
+public class GalleryViewModel extends ViewModel {
+
+    private final MutableLiveData<Boolean> isCreatedSongSyncing;
+    private final MutableLiveData<Boolean> isModifiedSongSyncing;
+    private final MutableLiveData<Boolean> isDeletedSongSyncing;
+    private final MutableLiveData<Boolean> isFetchingActive;
+    private SongSyncModule songSyncModule;
+
+    public GalleryViewModel() {
+
+        isCreatedSongSyncing = new MutableLiveData<>();
+        isCreatedSongSyncing.setValue(false);
+
+        isModifiedSongSyncing = new MutableLiveData<>();
+        isModifiedSongSyncing.setValue(false);
+
+        isDeletedSongSyncing = new MutableLiveData<>();
+        isDeletedSongSyncing.setValue(false);
+
+        isFetchingActive = new MutableLiveData<>();
+        isFetchingActive.setValue(false);
+    }
+
+    public MutableLiveData<Boolean> getIsCreatedSongSyncing() {
+        return isCreatedSongSyncing;
+    }
+
+    public void startCreateSongSyncing() {
+        if(this.songSyncModule == null) throw new RuntimeException("SongSyncModule is not initialized");
+        this.isCreatedSongSyncing.setValue(true);
+
+        this.songSyncModule.syncCreatedSongs();
+    }
+
+    public void finishCreateSongSyncing() {
+        this.isCreatedSongSyncing.setValue(false);
+    }
+
+    public void setSongSyncModule(SongSyncModule songSyncModule) {
+        this.songSyncModule = songSyncModule;
+    }
+
+    public void startModifiedSongSyncinc() {
+        if(this.songSyncModule == null) throw new RuntimeException("SongSyncModule is not initialized");
+        this.isModifiedSongSyncing.setValue(true);
+        this.songSyncModule.syncModifiedSongs();
+    }
+
+    public MutableLiveData<Boolean> getIsModifiedSongSyncing() {
+        return isModifiedSongSyncing;
+    }
+
+    public void finishModifiedSongSyncinc() {
+        this.isModifiedSongSyncing.setValue(false);
+    }
+
+    public MutableLiveData<Boolean> getIsDeletedSongSyncing() {
+        return isDeletedSongSyncing;
+    }
+
+    public void startDeletedSongSyncing() {
+        if(this.songSyncModule == null) throw new RuntimeException("SongSyncModule is not initialized");
+        this.isDeletedSongSyncing.setValue(true);
+        this.songSyncModule.syncDeletedSongs();
+    }
+
+    public void finishDeleteSongSyncinc() {
+        this.isDeletedSongSyncing.setValue(false);
+    }
+
+    public void startFetchingActive() {
+        if(this.songSyncModule == null) throw new RuntimeException("SongSyncModule is not initialized");
+        this.isFetchingActive.setValue(true);
+        this.songSyncModule.fetchRemoteModifiedSongs();
+    }
+
+    public void finishFetching() {
+        this.isFetchingActive.setValue(false);
+    }
+
+    public MutableLiveData<Boolean> getIsFetchingActive() {
+        return isFetchingActive;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/home/HomeFragment.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/home/HomeFragment.java
@ -0,0 +1,138 @@
+package com.stormtales.notevault.ui.home;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+import android.widget.Toast;
+import androidx.activity.result.ActivityResult;
+import androidx.activity.result.ActivityResultCallback;
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.recyclerview.widget.DividerItemDecoration;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
+import com.stormtales.notevault.R;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.repositories.SongRepository;
+import com.stormtales.notevault.databinding.FragmentHomeBinding;
+import com.stormtales.notevault.ui.sheetdisplay.NoteSheetDisplayActivity;
+import com.stormtales.notevault.ui.songeditor.SongEditorDialog;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class HomeFragment extends Fragment {
+
+    private FragmentHomeBinding binding;
+    private RecyclerView recyclerView;
+    private SongAdapter songAdapter;
+    private HomeViewModel homeViewModel;
+    private static final int PICK_FILE_REQUEST_CODE = 1;
+
+    public View onCreateView(@NonNull LayoutInflater inflater,
+                             ViewGroup container, Bundle savedInstanceState) {
+        homeViewModel = new ViewModelProvider(this).get(HomeViewModel.class);
+        homeViewModel.setSongRepository(new SongRepository(this.getContext()));
+
+        binding = FragmentHomeBinding.inflate(inflater, container, false);
+        View root = binding.getRoot();
+        recyclerView = root.findViewById(R.id.recycler_view_songs);
+
+        ActivityResultLauncher<Intent> launcher = registerForActivityResult(
+                new ActivityResultContracts.StartActivityForResult(),
+                activityResult -> {
+                    getActivity();
+                    if(activityResult.getResultCode() == Activity.RESULT_OK && activityResult.getData() != null) {
+                        if(activityResult.getData().getClipData() != null) {
+                            int fileNumber = activityResult.getData().getClipData().getItemCount();
+                            Uri[] files = new Uri[fileNumber];
+                            for(int i = 0; i < fileNumber; i++) {
+                                files[i] = activityResult.getData().getClipData().getItemAt(i).getUri();
+                                Toast.makeText(requireContext(), "Uri: " + files[i].toString(), Toast.LENGTH_SHORT).show();
+                            }
+                            handleSelectedNoteSheets(files);
+                        } else {
+                            Uri uri = activityResult.getData().getData();
+                            Toast.makeText(requireContext(), "Uri: " + uri.toString(), Toast.LENGTH_SHORT).show();
+                            handleSelectedNoteSheets(uri);
+                        }
+                    }
+                }
+        );
+
+        FloatingActionButton importBtn = root.findViewById(R.id.addSongBtn);
+        importBtn.setOnClickListener(v -> {
+            Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
+            intent.setType("*/*"); // Alle Dateitypen
+
+            String[] mimeTypes = {"application/pdf", "image/png", "image/jpeg"};
+            intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes);
+            intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
+
+            intent.addCategory(Intent.CATEGORY_OPENABLE);
+
+
+            launcher.launch(intent);
+        });
+
+        // RecyclerView einrichten
+        songAdapter = new SongAdapter(new ArrayList<>(), this::onEditSong, this::onDeleteSong, this::onOpenSong);
+        recyclerView.setAdapter(songAdapter);
+        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
+        DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), LinearLayoutManager.VERTICAL);
+        recyclerView.addItemDecoration(dividerItemDecoration);
+
+        // Beobachte Änderungen in der Song-Liste
+        homeViewModel.getAllSongsLive().observe(getViewLifecycleOwner(), songs -> {
+            songAdapter.updateData(songs);
+        });
+
+        return root;
+    }
+
+    @Override
+    public void onDestroyView() {
+        super.onDestroyView();
+        binding = null;
+    }
+
+    private void handleSelectedNoteSheets(Uri... files) {
+        SongEditorDialog songEditorDialog = new SongEditorDialog();
+        songEditorDialog.setNoteSheetFiles(files);
+        songEditorDialog.setHomeViewModel(homeViewModel);
+        songEditorDialog.show(getParentFragmentManager(), "songEditorDialog");
+    }
+
+    public void onEditSong(Song song) {
+        SongEditorDialog songEditorDialog = new SongEditorDialog();
+        songEditorDialog.setEditedSong(song);
+        songEditorDialog.setHomeViewModel(homeViewModel);
+        songEditorDialog.show(getParentFragmentManager(), "songEditorDialog");
+    }
+
+    public void onDeleteSong(Song song) {
+        this.homeViewModel.deleteSong(song);
+    }
+
+    public void onOpenSong(Song song) {
+        homeViewModel.getSongRepository().getNoteSheetFilesBySongID(song.getLocalID(), result -> {
+            String[] noteSheetFiles = new String[result.size()];
+            for(int i = 0; i < result.size(); i++) {
+                noteSheetFiles[i] = result.get(i);
+            }
+            Intent intent = new Intent(getContext(), NoteSheetDisplayActivity.class);
+            intent.putExtra("imageUris", noteSheetFiles);
+            getContext().startActivity(intent);
+
+        });
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/home/HomeViewModel.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/home/HomeViewModel.java
@ -0,0 +1,88 @@
+package com.stormtales.notevault.ui.home;
+
+import android.util.Log;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.repositories.SongRepository;
+import com.stormtales.notevault.data.sync.SyncStatus;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class HomeViewModel extends ViewModel {
+
+    private MutableLiveData<List<Song>> allSongs;
+    private SongRepository songRepository;
+
+    public HomeViewModel() {
+        List<Song> currentSongs = new ArrayList<>();
+        this.allSongs = new MutableLiveData<>(currentSongs);
+        /*this.allSongs.setValue(songRepository.getAllSongs());*/
+    }
+
+    public void addSong(Song song, List<NoteSheet> noteSheetList) {
+        songRepository.insert(song, internalSongID -> {
+            for(NoteSheet noteSheet : noteSheetList) {
+                noteSheet.setSongID(Math.toIntExact(internalSongID));
+            }
+            songRepository.insertNoteSheets(noteSheetList);
+        });
+
+
+        List<Song> currentSongs = allSongs.getValue();
+        if(currentSongs == null) {
+            currentSongs = new ArrayList<>();
+        }
+
+        // Neue Liste erstellen und den Song hinzufügen
+        List<Song> updatedSongs = new ArrayList<>(currentSongs);
+        updatedSongs.add(song);
+        // Neue Liste in MutableLiveData setzen
+        allSongs.setValue(updatedSongs);
+        Log.d("HomeViewModel", "Song added. Total songs: " + updatedSongs.size());
+    }
+
+    public LiveData<List<Song>> getAllSongsLive() {
+        return allSongs;
+    }
+
+    public void setSongRepository(SongRepository songRepository) {
+        this.songRepository = songRepository;
+        loadAllSongs();
+    }
+
+    public void loadAllSongs() {
+        songRepository.getAllSongs(songs->allSongs.setValue(songs));
+    }
+
+    public void deleteSong(Song song) {
+        songRepository.deleteSong(song);
+
+        List<Song> currentSongs = allSongs.getValue();
+        if(currentSongs != null) {
+            currentSongs.remove(song);
+            allSongs.setValue(currentSongs);
+        }
+    }
+
+    public void updateSong(Song editedSong) {
+        List<Song> currentSongs = allSongs.getValue();
+        if(currentSongs != null) {
+            for(int i = 0; i < currentSongs.size(); i++) {
+                if(currentSongs.get(i).getLocalID() == editedSong.getLocalID()) {
+                    currentSongs.set(i, editedSong);
+                    break;
+                }
+            }
+            songRepository.updateSong(editedSong);
+            allSongs.setValue(currentSongs);
+        }
+    }
+
+    public SongRepository getSongRepository() {
+        return songRepository;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/home/SongAdapter.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/home/SongAdapter.java
@ -0,0 +1,99 @@
+package com.stormtales.notevault.ui.home;
+
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageButton;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+import com.stormtales.notevault.R;
+import com.stormtales.notevault.data.entities.Song;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class SongAdapter extends RecyclerView.Adapter<SongAdapter.SongViewHolder> {
+
+    private List<Song> songList;
+    private OnEditSongListener onEditSongListener;
+    private OnDeleteSongListener onDeleteSongListener;
+    private OnOpenSongListener onOpenSongListener;
+
+    public SongAdapter(List<Song> songList, OnEditSongListener onEditSongListener, OnDeleteSongListener onDeleteSongListener, OnOpenSongListener onOpenSongListener) {
+        this.songList = songList;
+        this.onEditSongListener = onEditSongListener;
+        this.onDeleteSongListener = onDeleteSongListener;
+        this.onOpenSongListener = onOpenSongListener;
+    }
+
+    public void updateData(List<Song> songs) {
+        if (songs == null) {
+            this.songList = new ArrayList<>();
+        } else {
+            this.songList = new ArrayList<>(songs);
+        }
+        notifyDataSetChanged();
+        Log.d("SongAdapter", "Data updated: " + this.songList.size());
+    }
+
+    public class SongViewHolder extends RecyclerView.ViewHolder {
+        TextView textYear, textComposition, textTitle;
+        ImageButton editButton, deleteButton;
+
+        public SongViewHolder(View itemView) {
+            super(itemView);
+            textYear = itemView.findViewById(R.id.text_year);
+            textComposition = itemView.findViewById(R.id.text_composition);
+            textTitle = itemView.findViewById(R.id.text_title);
+            editButton = itemView.findViewById(R.id.edit_song_button);
+            deleteButton = itemView.findViewById(R.id.delete_song_button);
+
+            textTitle.setOnClickListener(v -> {
+                int position = getAdapterPosition();
+                if (position != RecyclerView.NO_POSITION) {
+                    Song song = songList.get(position);
+                    onOpenSongListener.onOpenSong(song);
+                }
+            });
+        }
+    }
+
+    @NonNull
+    @Override
+    public @NotNull SongViewHolder onCreateViewHolder(@NonNull @NotNull ViewGroup parent, int i) {
+        View itemView = LayoutInflater.from(parent.getContext())
+                .inflate(R.layout.item_song, parent, false);
+        return new SongViewHolder(itemView);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull @NotNull SongAdapter.SongViewHolder holder, int position) {
+        Song song = songList.get(position);
+        holder.textYear.setText(String.valueOf(song.getYear()));
+        holder.textComposition.setText(song.getComposer());
+        holder.textTitle.setText(song.getTitle());
+
+        holder.editButton.setOnClickListener(v -> onEditSongListener.onEditSong(song));
+        holder.deleteButton.setOnClickListener(v -> onDeleteSongListener.onDeleteSong(song));
+    }
+
+    @Override
+    public int getItemCount() {
+        return songList.size();
+    }
+
+    public interface OnEditSongListener {
+        void onEditSong(Song song);
+    }
+
+    public interface OnDeleteSongListener {
+        void onDeleteSong(Song song);
+    }
+
+    public interface OnOpenSongListener {
+        void onOpenSong(Song song);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/login/LoginDialog.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/login/LoginDialog.java
@ -0,0 +1,156 @@
+package com.stormtales.notevault.ui.login;
+
+import android.app.AlertDialog;
+import android.app.Dialog;
+import android.content.Context;
+import android.os.Bundle;
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.util.Log;
+import android.view.KeyEvent;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.inputmethod.EditorInfo;
+import android.widget.*;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.DialogFragment;
+import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
+import com.stormtales.notevault.R;
+import com.stormtales.notevault.network.APICallback;
+import com.stormtales.notevault.network.auth.AuthService;
+import org.jetbrains.annotations.NotNull;
+
+public class LoginDialog extends DialogFragment {
+
+    private LoginViewModel loginViewModel;
+    private boolean isLoginMode = true;
+    private Dialog dialog;
+
+    private Button loginButton;
+    private ProgressBar loadingProgressBar;
+    private EditText editTextUsername;
+    private EditText editTextPassword;
+    private EditText editTextEmail;
+    private TextView textViewTitle;
+    private TextView textViewSwitch;
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+
+    }
+
+    public LoginDialog(LoginViewModel loginViewModel) {
+        this.loginViewModel = loginViewModel;
+    }
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(requireContext());
+        LayoutInflater inflater = requireActivity().getLayoutInflater();
+        View view = inflater.inflate(R.layout.fragment_login_dialog, null);
+
+        textViewTitle = view.findViewById(R.id.textViewTitle);
+        editTextUsername = view.findViewById(R.id.editTextUsername);
+        editTextEmail = view.findViewById(R.id.editTextEmail);
+        editTextPassword = view.findViewById(R.id.editTextPassword);
+        loginButton = view.findViewById(R.id.buttonAction);
+        textViewSwitch = view.findViewById(R.id.textViewSwitch);
+        loadingProgressBar = view.findViewById(R.id.loading);
+        // Handle action button click
+
+
+        // Toggle between Login and Registration
+        textViewSwitch.setOnClickListener(v -> {
+            isLoginMode = !isLoginMode;
+            textViewTitle.setText(isLoginMode ? "Login" : "Register");
+            editTextUsername.setVisibility(isLoginMode ? View.GONE : View.VISIBLE);
+            loginButton.setText(isLoginMode ? "Login" : "Register");
+            textViewSwitch.setText(isLoginMode ? "Don't have an account? Register" : "Already have an account? Login");
+        });
+
+        builder.setView(view);
+        dialog = builder.create();
+
+
+
+        TextWatcher afterTextChangedListener = new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                loginViewModel.updateLoginData(editTextUsername.getText().toString(), editTextPassword.getText().toString());
+            }
+        };
+
+        editTextUsername.addTextChangedListener(afterTextChangedListener);
+        editTextPassword.addTextChangedListener(afterTextChangedListener);
+        editTextPassword.setOnEditorActionListener(new TextView.OnEditorActionListener() {
+            @Override
+            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
+                if(actionId == EditorInfo.IME_ACTION_DONE) {
+                    loginViewModel.performLogin(editTextUsername.getText().toString(), editTextPassword.getText().toString(), LoginDialog.this::onSuccessFullLogin);
+                }
+                return false;
+            }
+        });
+
+        loginButton.setOnClickListener(v -> {
+            loadingProgressBar.setVisibility(View.VISIBLE);
+            String email = editTextEmail.getText().toString();
+            String password = editTextPassword.getText().toString();
+            if (isLoginMode) {
+                // Handle login logic
+                this.loginViewModel.performLogin(email, password, this::onSuccessFullLogin);
+            } else {
+                // Handle registration logic
+                String username = editTextUsername.getText().toString();
+                this.loginViewModel.performRegistration(email, password, username, this::onSuccessFullRegistration);
+            }
+        });
+        return dialog;
+    }
+
+    private void onSuccessFullRegistration() {
+        Toast.makeText(getContext(), "Successfully registered", Toast.LENGTH_LONG).show();
+        this.isLoginMode = true;
+        textViewTitle.setText(isLoginMode ? "Login" : "Register");
+        editTextUsername.setVisibility(isLoginMode ? View.GONE : View.VISIBLE);
+        loginButton.setText(isLoginMode ? "Login" : "Register");
+        textViewSwitch.setText(isLoginMode ? "Don't have an account? Register" : "Already have an account? Login");
+    }
+
+    @Override
+    public void onViewCreated(@NonNull @NotNull View view, @Nullable @org.jetbrains.annotations.Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        loginViewModel.getLoginFormState().observe(getViewLifecycleOwner(), new Observer<LoginFormState>() {
+            @Override
+            public void onChanged(LoginFormState loginFormState) {
+                if(loginFormState == null) return;
+                loginButton.setEnabled(loginFormState.isDataValid());
+                if(loginFormState.getUsernameError() != null) {
+                    editTextUsername.setError(getString(loginFormState.getUsernameError()));
+                }
+                if(loginFormState.getPasswordError() != null) {
+                    editTextPassword.setError(getString(loginFormState.getPasswordError()));
+                }
+            }
+        });
+    }
+
+    void onSuccessFullLogin() {
+        this.dialog.dismiss();
+    }
+
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/login/LoginFormState.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/login/LoginFormState.java
@ -0,0 +1,37 @@
+package com.stormtales.notevault.ui.login;
+
+import androidx.annotation.Nullable;
+
+public class LoginFormState {
+    @Nullable
+    private Integer usernameError;
+    @Nullable
+    private Integer passwordError;
+    private boolean isDataValid;
+
+    LoginFormState(@Nullable Integer usernameError, @Nullable Integer passwordError) {
+        this.usernameError = usernameError;
+        this.passwordError = passwordError;
+        this.isDataValid = false;
+    }
+
+    LoginFormState(boolean isDataValid) {
+        this.usernameError = null;
+        this.passwordError = null;
+        this.isDataValid = isDataValid;
+    }
+
+    @Nullable
+    Integer getUsernameError() {
+        return usernameError;
+    }
+
+    @Nullable
+    Integer getPasswordError() {
+        return passwordError;
+    }
+
+    boolean isDataValid() {
+        return isDataValid;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/login/LoginViewModel.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/login/LoginViewModel.java
@ -0,0 +1,116 @@
+package com.stormtales.notevault.ui.login;
+
+import android.util.Log;
+import android.util.Patterns;
+import android.widget.Toast;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+import com.stormtales.notevault.R;
+import com.stormtales.notevault.network.APICallback;
+import com.stormtales.notevault.network.auth.AuthService;
+import com.stormtales.notevault.network.auth.LoginResponse;
+
+public class LoginViewModel extends ViewModel {
+
+    private final MutableLiveData<String> username;
+    private final MutableLiveData<Boolean> isLoggedIn;
+    private MutableLiveData<LoginFormState> loginFormState = new MutableLiveData<>();
+    private AuthService authService;
+
+    public LoginViewModel() {
+        username = new MutableLiveData<>("Not Logged In");
+        isLoggedIn = new MutableLiveData<>(false);
+    }
+
+    public void performLogin(String email, String password, SuccessFullLoginCallback successFullLoginCallback) {
+        if(authService != null) {
+            authService.performLogin(email, password, new LoginCallBackImpl(successFullLoginCallback));
+        } else {
+            throw new RuntimeException("AuthService is not provided to LoginViewModel");
+        }
+    }
+
+    public void performRegistration(String email, String password, String username, SuccessFullLoginCallback successFullLoginCallback) {
+        if(authService != null) {
+            authService.performRegistration(email, username, password, new APICallback() {
+                @Override
+                public void onSuccess() {
+                    successFullLoginCallback.onSuccess();
+                }
+
+                @Override
+                public void onError(String error) {
+                    Log.d("LoginService", error);
+                }
+            });
+        }
+    }
+
+    public void setAuthService(AuthService authService) {
+        this.authService = authService;
+    }
+
+    public MutableLiveData<Boolean> getIsLoggedIn() {
+        return isLoggedIn;
+    }
+
+    public MutableLiveData<String> getUsername() {
+        return username;
+    }
+
+    public void updateLoginData(String username, String password) {
+        if(!isUserNameValid(username)) {
+            loginFormState.setValue(new LoginFormState(R.string.invalid_username, null));
+        } else if(!isPasswordValid(password)) {
+            loginFormState.setValue(new LoginFormState(null, R.string.invalid_password));
+        } else {
+            loginFormState.setValue(new LoginFormState(true));
+        }
+    }
+
+    public class LoginCallBackImpl implements AuthService.LoginCallback {
+
+        private final SuccessFullLoginCallback successFullLoginCallback;
+
+        public LoginCallBackImpl(SuccessFullLoginCallback successFullLoginCallback) {
+            this.successFullLoginCallback = successFullLoginCallback;
+        }
+
+        @Override
+        public void onSuccess(LoginResponse loginResponse) {
+            username.setValue(loginResponse.getUsername());
+            isLoggedIn.setValue(true);
+            successFullLoginCallback.onSuccess();
+        }
+
+        @Override
+        public void onError(String error) {
+            Log.d("LoginService", error);
+        }
+    }
+
+    public interface SuccessFullLoginCallback {
+        void onSuccess();
+    }
+
+    public MutableLiveData<LoginFormState> getLoginFormState() {
+        return loginFormState;
+    }
+
+    // A placeholder username validation check
+    private boolean isUserNameValid(String username) {
+        if (username == null) {
+            return false;
+        }
+        if (username.contains("@")) {
+            return Patterns.EMAIL_ADDRESS.matcher(username).matches();
+        } else {
+            return !username.trim().isEmpty();
+        }
+    }
+
+    // A placeholder password validation check
+    private boolean isPasswordValid(String password) {
+        return password != null && password.trim().length() > 5;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/sheetdisplay/ImagePagerAdapter.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/sheetdisplay/ImagePagerAdapter.java
@ -0,0 +1,51 @@
+package com.stormtales.notevault.ui.sheetdisplay;
+
+
+import android.content.Context;
+import android.net.Uri;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+import com.github.chrisbanes.photoview.PhotoView;
+import com.stormtales.notevault.R;
+
+import java.util.List;
+
+public class ImagePagerAdapter extends RecyclerView.Adapter<ImagePagerAdapter.ImageViewHolder> {
+    private final List<String> imageUris;
+    private final Context context;
+
+    public ImagePagerAdapter(Context context, List<String> imageUris) {
+        this.context = context;
+        this.imageUris = imageUris;
+    }
+
+    @NonNull
+    @Override
+    public ImageViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        View view = LayoutInflater.from(context).inflate(R.layout.item_image, parent, false);
+        return new ImageViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ImageViewHolder holder, int position) {
+        Uri uri = Uri.parse(imageUris.get(position));
+        holder.photoView.setImageURI(uri);
+    }
+
+    @Override
+    public int getItemCount() {
+        return imageUris.size();
+    }
+
+    static class ImageViewHolder extends RecyclerView.ViewHolder {
+        PhotoView photoView;
+
+        ImageViewHolder(View itemView) {
+            super(itemView);
+            photoView = itemView.findViewById(R.id.photoView);
+        }
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/sheetdisplay/NoteSheetDisplayActivity.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/sheetdisplay/NoteSheetDisplayActivity.java
@ -0,0 +1,40 @@
+package com.stormtales.notevault.ui.sheetdisplay;
+
+import android.content.Intent;
+import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.viewpager2.widget.ViewPager2;
+import com.google.android.material.tabs.TabLayout;
+import com.google.android.material.tabs.TabLayoutMediator;
+import com.stormtales.notevault.R;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class NoteSheetDisplayActivity extends AppCompatActivity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_note_sheet_viewer); // Erstelle eine Layout-Datei
+
+        ViewPager2 imageView = findViewById(R.id.viewPager); // Angenommen, du hast ein ImageView
+        TabLayout tabLayout = findViewById(R.id.tabLayout);
+
+
+
+        // Die URI aus dem Intent erhalten
+        Intent intent = getIntent();
+        String[] imageUris = intent.getStringArrayExtra("imageUris");
+        if (imageUris != null) {
+            List<String> uriList = Arrays.asList(imageUris);
+            ImagePagerAdapter adapter = new ImagePagerAdapter(this, uriList);
+            imageView.setAdapter(adapter); // Setze die URI in das ImageView
+
+            new TabLayoutMediator(tabLayout, imageView,
+                    (tab, position) -> tab.setText("Sheet " + (position + 1)) // Hier kannst du auch andere Labels verwenden
+            ).attach();
+        } else {
+            throw new NullPointerException();
+        }
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/slideshow/SlideshowFragment.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/slideshow/SlideshowFragment.java
@ -0,0 +1,35 @@
+package com.stormtales.notevault.ui.slideshow;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.fragment.app.Fragment;
+import androidx.lifecycle.ViewModelProvider;
+import com.stormtales.notevault.databinding.FragmentSlideshowBinding;
+
+public class SlideshowFragment extends Fragment {
+
+    private FragmentSlideshowBinding binding;
+
+    public View onCreateView(@NonNull LayoutInflater inflater,
+                             ViewGroup container, Bundle savedInstanceState) {
+        SlideshowViewModel slideshowViewModel =
+                new ViewModelProvider(this).get(SlideshowViewModel.class);
+
+        binding = FragmentSlideshowBinding.inflate(inflater, container, false);
+        View root = binding.getRoot();
+
+        final TextView textView = binding.textSlideshow;
+        slideshowViewModel.getText().observe(getViewLifecycleOwner(), textView::setText);
+        return root;
+    }
+
+    @Override
+    public void onDestroyView() {
+        super.onDestroyView();
+        binding = null;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/slideshow/SlideshowViewModel.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/slideshow/SlideshowViewModel.java
@ -0,0 +1,19 @@
+package com.stormtales.notevault.ui.slideshow;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+public class SlideshowViewModel extends ViewModel {
+
+    private final MutableLiveData<String> mText;
+
+    public SlideshowViewModel() {
+        mText = new MutableLiveData<>();
+        mText.setValue("This is slideshow fragment");
+    }
+
+    public LiveData<String> getText() {
+        return mText;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/ui/songeditor/SongEditorDialog.java
+++ b/app/src/main/java/com/stormtales/notevault/ui/songeditor/SongEditorDialog.java
@ -0,0 +1,193 @@
+package com.stormtales.notevault.ui.songeditor;
+
+import android.app.AlertDialog;
+import android.app.Dialog;
+import android.content.Context;
+import android.net.Uri;
+import android.os.Bundle;
+import android.text.Layout;
+import android.util.Log;
+import android.widget.Button;
+import android.widget.EditText;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.DialogFragment;
+import androidx.fragment.app.Fragment;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.lifecycle.ViewModelProvider;
+import com.stormtales.notevault.R;
+import com.stormtales.notevault.data.entities.NoteSheet;
+import com.stormtales.notevault.data.entities.Song;
+import com.stormtales.notevault.data.sync.SyncStatus;
+import com.stormtales.notevault.network.sync.SongSyncService;
+import com.stormtales.notevault.network.sync.models.AIRecognizedSong;
+import com.stormtales.notevault.ui.home.HomeViewModel;
+import com.stormtales.notevault.utils.NoteSheetsUtil;
+import com.stormtales.notevault.utils.Tupel;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+
+public class SongEditorDialog extends DialogFragment {
+
+    Dialog dialog;
+    private Uri[] noteSheetFiles;
+    private HomeViewModel homeViewModel;
+
+    private Song editedSong;
+    private SongSyncService songSyncService;
+
+    private View progressbar;
+    public SongEditorDialog() {
+        // Required empty public constructor
+        this.songSyncService = new SongSyncService(this.getContext());
+    }
+
+
+    @NonNull
+    @Override
+    public @NotNull Dialog onCreateDialog(@Nullable @org.jetbrains.annotations.Nullable Bundle savedInstanceState) {
+        LayoutInflater inflater = LayoutInflater.from(getContext());
+        View dialogView = inflater.inflate(R.layout.fragment_song_editor_dialog, null);
+
+
+        dialogView.findViewById(R.id.btnCancel).setOnClickListener(v-> onCancel());
+        dialogView.findViewById(R.id.btnSave).setOnClickListener(v -> onSave());
+
+        if(this.noteSheetFiles == null || noteSheetFiles.length == 0) {
+            dialogView.findViewById(R.id.btnAutoDetect).setEnabled(false);
+        } else {
+            progressbar = dialogView.findViewById(R.id.spinnerAutoDetect);
+
+        }
+
+        dialogView.findViewById(R.id.btnAutoDetect).setOnClickListener(v -> {
+            progressbar.setVisibility(ViewGroup.VISIBLE);
+            extractTitleFromFirstPage();
+        });
+
+        AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
+        builder.setCancelable(false);
+        builder.setView(dialogView);
+
+        dialog = builder.create();
+        dialog.setCanceledOnTouchOutside(false);
+        return dialog;
+    }
+
+    private File createTemporaryFileForRecognition(Uri noteSheetUri) {
+        try {
+            // Hole den InputStream des Bildes
+            InputStream inputStream = getContext().getContentResolver().openInputStream(noteSheetUri);
+            if (inputStream != null) {
+                // Erstelle eine temporäre Datei
+                File tempFile = File.createTempFile("temp_note_sheet", ".jpg", getContext().getCacheDir());
+
+                // Inhalt des InputStreams in die temporäre Datei schreiben
+                try (OutputStream outputStream = new FileOutputStream(tempFile)) {
+                    byte[] buffer = new byte[8192];
+                    int bytesRead;
+                    while ((bytesRead = inputStream.read(buffer)) != -1) {
+                        outputStream.write(buffer, 0, bytesRead);
+                    }
+                }
+
+                // Schließe den InputStream
+                inputStream.close();
+
+                return tempFile;
+            }
+        } catch (Exception e) {
+            Log.e("SongEditorDialog", "Fehler beim Erstellen der temporären Datei: " + e.getMessage());
+        }
+
+        return null;
+    }
+    private void extractTitleFromFirstPage() {
+        if(noteSheetFiles != null && noteSheetFiles.length > 0) {
+            Uri firstPageUri = noteSheetFiles[0];
+
+            // Temporäre Datei erstellen
+            File tempFile = createTemporaryFileForRecognition(firstPageUri);
+            if(tempFile != null) {
+                songSyncService.recognizeTitle(tempFile.getAbsolutePath(), new SongSyncService.RecognizedSongCallback() {
+                    @Override
+                    public void onRecognizedSong(AIRecognizedSong aiRecognizedSong) {
+                        progressbar.setVisibility(ViewGroup.GONE);
+                        ((EditText) dialog.findViewById(R.id.etTitle)).setText(aiRecognizedSong.getTitle());
+                        ((EditText) dialog.findViewById(R.id.etComposer)).setText(aiRecognizedSong.getComposer());
+                        ((EditText) dialog.findViewById(R.id.etYear)).setText(String.valueOf(aiRecognizedSong.getYear()));
+                        ((EditText) dialog.findViewById(R.id.etGenre)).setText(aiRecognizedSong.getDescription());
+                    }
+                });
+            }
+        }
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        if(editedSong != null) {
+            ((EditText) dialog.findViewById(R.id.etTitle)).setText(editedSong.getTitle());
+            ((EditText) dialog.findViewById(R.id.etComposer)).setText(editedSong.getComposer());
+            ((EditText) dialog.findViewById(R.id.etGenre)).setText(editedSong.getGenre());
+            ((EditText) dialog.findViewById(R.id.etYear)).setText(String.valueOf(editedSong.getYear()));
+        }
+    }
+
+    private void onCancel() {
+        dialog.dismiss();
+    }
+
+    private void onSave() {
+        String title = ((EditText) dialog.findViewById(R.id.etTitle)).getText().toString();
+        String composer = ((EditText) dialog.findViewById(R.id.etComposer)).getText().toString();
+
+        String year_string = ((EditText) dialog.findViewById(R.id.etYear)).getText().toString();
+        int releaseYear = year_string.isBlank()? 0 : Integer.parseInt(year_string);
+        String genre = ((EditText) dialog.findViewById(R.id.etGenre)).getText().toString();
+
+        if(editedSong != null) {
+            editedSong.setTitle(title);
+            editedSong.setComposer(composer);
+            editedSong.setYear(releaseYear);
+            editedSong.setGenre(genre);
+            editedSong.setSyncStatus(SyncStatus.MODIFIED);
+            homeViewModel.updateSong(editedSong);
+        } else {
+            Song song = new Song(title, composer, genre, releaseYear);
+
+            Context context = this.getContext();
+            List<NoteSheet> noteSheetList = new ArrayList<>();
+            for(Uri uri : noteSheetFiles) {
+                Tupel<String, String> result = NoteSheetsUtil.saveImageInternally(context.getContentResolver(), uri, context.getFilesDir());
+                noteSheetList.add(new NoteSheet(result.getValue00(), result.getValue01()));
+            }
+            homeViewModel.addSong(song, noteSheetList);
+        }
+
+
+        dialog.dismiss();
+
+    }
+
+    public void setNoteSheetFiles(Uri[] noteSheetFiles) {
+        this.noteSheetFiles = noteSheetFiles;
+    }
+
+    public void setHomeViewModel(HomeViewModel homeViewModel) {
+        this.homeViewModel = homeViewModel;
+    }
+
+    public void setEditedSong(Song editedSong) {
+        this.editedSong = editedSong;
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/utils/NoteSheetsUtil.java
+++ b/app/src/main/java/com/stormtales/notevault/utils/NoteSheetsUtil.java
@ -0,0 +1,117 @@
+package com.stormtales.notevault.utils;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.media.ExifInterface;
+import android.net.Uri;
+import okhttp3.ResponseBody;
+
+import java.io.*;
+import java.nio.file.Files;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.*;
+
+public class NoteSheetsUtil {
+    private static long getImageTimestamp(Context context, Uri imageUri) {
+        try  {
+            InputStream inputStream = context.getContentResolver().openInputStream(imageUri);
+            ExifInterface exif = new ExifInterface(inputStream);
+
+            String dateTime = exif.getAttribute(ExifInterface.TAG_DATETIME);
+            if(dateTime != null) {
+                SimpleDateFormat format = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss", Locale.getDefault());
+                Date date = format.parse(dateTime);
+                return date != null ? date.getTime() : 0;
+            } else {
+                File file = new File(imageUri.getPath());
+                return file.lastModified();
+            }
+        } catch (IOException | ParseException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static void sortNoteSheetsByTimestamp(Context context, Uri[] uris) {
+        ArrayList<UriTimestamp> uriTimestamps = new ArrayList<>();
+
+        for(Uri uri : uris) {
+            long timestamp = getImageTimestamp(context, uri);
+            uriTimestamps.add(new UriTimestamp(uri, timestamp));
+        }
+
+        Collections.sort(uriTimestamps, Comparator.comparingLong(UriTimestamp::getTimestamp));
+
+        for(int i=0; i<uriTimestamps.size(); i++) {
+            uris[i] = uriTimestamps.get(i).getUri();
+        }
+    }
+
+    public static Tupel<String, String> saveImageInternally(ContentResolver contentResolver, Uri uri, File filesDir) {
+        try (InputStream inputStream = contentResolver.openInputStream(uri)) {
+            // Datei erstellen
+            File imageFile = new File(filesDir, "saved_image_" + System.currentTimeMillis() + ".jpg");
+            try (OutputStream outputStream = Files.newOutputStream(imageFile.toPath())) {
+                // SHA-256 Hash-Funktion initialisieren
+                MessageDigest digest = MessageDigest.getInstance("SHA-256");
+
+                // Daten blockweise lesen und gleichzeitig schreiben und hashen
+                byte[] buffer = new byte[4096];
+                int bytesRead;
+                while ((bytesRead = inputStream.read(buffer)) != -1) {
+                    outputStream.write(buffer, 0, bytesRead);
+                    digest.update(buffer, 0, bytesRead); // Hash aktualisieren
+                }
+
+                // Hash berechnen
+                byte[] hashBytes = digest.digest();
+                StringBuilder hashString = new StringBuilder();
+                for (byte b : hashBytes) {
+                    hashString.append(String.format("%02x", b)); // Bytes in Hexadezimal umwandeln
+                }
+
+                // Hashwert zurückgeben (kann auch zusammen mit dem Pfad gespeichert werden)
+                return new Tupel<>(imageFile.getAbsolutePath(), hashString.toString());
+            } catch (NoSuchAlgorithmException e) {
+                throw new RuntimeException(e);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public static Tupel<String, String> saveImageFromServer(ResponseBody body, File filesDir) {
+        File imageFile = new File(filesDir, "saved_image_" + System.currentTimeMillis() + ".jpg");
+        try (InputStream inputStream = body.byteStream();
+             FileOutputStream outputStream = new FileOutputStream(imageFile)) {
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+
+            // Daten blockweise lesen und gleichzeitig schreiben und hashen
+            byte[] buffer = new byte[4096];
+            int bytesRead;
+            while ((bytesRead = inputStream.read(buffer)) != -1) {
+                outputStream.write(buffer, 0, bytesRead);
+                digest.update(buffer, 0, bytesRead); // Hash aktualisieren
+            }
+
+            // Hash berechnen
+            byte[] hashBytes = digest.digest();
+            StringBuilder hashString = new StringBuilder();
+            for (byte b : hashBytes) {
+                hashString.append(String.format("%02x", b)); // Bytes in Hexadezimal umwandeln
+            }
+
+            // Hashwert zurückgeben (kann auch zusammen mit dem Pfad gespeichert werden)
+            return new Tupel<>(imageFile.getAbsolutePath(), hashString.toString());
+        } catch (IOException | NoSuchAlgorithmException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static void deleteNoteSheet(String filePath) throws IOException {
+        Files.delete(new File(filePath).toPath());
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/utils/Tupel.java
+++ b/app/src/main/java/com/stormtales/notevault/utils/Tupel.java
@ -0,0 +1,33 @@
+package com.stormtales.notevault.utils;
+
+import java.util.Objects;
+
+public class Tupel<A,B> {
+    private final A value00;
+    private final B value01;
+
+    public Tupel(A value00, B value01) {
+        this.value00 = value00;
+        this.value01 = value01;
+    }
+
+    public A getValue00() {
+        return value00;
+    }
+
+    public B getValue01() {
+        return value01;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) return false;
+        Tupel<?, ?> tupel = (Tupel<?, ?>) o;
+        return Objects.equals(value00, tupel.value00) && Objects.equals(value01, tupel.value01);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(value00, value01);
+    }
+}
--- a/app/src/main/java/com/stormtales/notevault/utils/UriTimestamp.java
+++ b/app/src/main/java/com/stormtales/notevault/utils/UriTimestamp.java
@ -0,0 +1,21 @@
+package com.stormtales.notevault.utils;
+
+import android.net.Uri;
+
+public class UriTimestamp {
+    private final Uri uri;
+    private final long timestamp;
+
+    public UriTimestamp(Uri uri, long timestamp) {
+        this.uri = uri;
+        this.timestamp = timestamp;
+    }
+
+    public Uri getUri() {
+        return uri;
+    }
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+}
--- a/app/src/main/java/come/stormborntales/notevault/FullScreenActivity.kt
+++ b/app/src/main/java/come/stormborntales/notevault/FullScreenActivity.kt
@ -1,26 +0,0 @@
-package come.stormborntales.notevault
-
-import android.net.Uri
-import android.os.Bundle
-import androidx.activity.ComponentActivity
-import androidx.activity.compose.setContent
-import come.stormborntales.notevault.ui.screens.FullscreenImageViewer
-import come.stormborntales.notevault.ui.theme.NoteVaultTheme
-
-// FullscreenImageViewerActivity.kt
-class FullscreenImageViewerActivity : ComponentActivity() {
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-
-        val imageUris = intent.getParcelableArrayListExtra<Uri>("imageUris") ?: emptyList()
-
-        setContent {
-            NoteVaultTheme {
-                FullscreenImageViewer(
-                    images = imageUris,
-                    onClose = { finish() }
-                )
-            }
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/MainActivity.kt
+++ b/app/src/main/java/come/stormborntales/notevault/MainActivity.kt
@ -1,253 +0,0 @@
-package come.stormborntales.notevault
-
-import android.net.Uri
-import android.os.Bundle
-import android.util.Log
-import androidx.activity.ComponentActivity
-import androidx.activity.compose.rememberLauncherForActivityResult
-import androidx.activity.compose.setContent
-import androidx.activity.result.contract.ActivityResultContracts
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.AccountCircle
-import androidx.compose.material.icons.filled.Menu
-import androidx.compose.material3.DrawerValue
-import androidx.compose.material3.DropdownMenu
-import androidx.compose.material3.DropdownMenuItem
-import androidx.compose.material3.ExperimentalMaterial3Api
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.ModalDrawerSheet
-import androidx.compose.material3.ModalNavigationDrawer
-import androidx.compose.material3.NavigationDrawerItem
-import androidx.compose.material3.NavigationDrawerItemDefaults
-import androidx.compose.material3.Scaffold
-import androidx.compose.material3.Text
-import androidx.compose.material3.TextField
-import androidx.compose.material3.TextFieldDefaults
-import androidx.compose.material3.TopAppBar
-import androidx.compose.material3.rememberDrawerState
-import androidx.compose.runtime.*
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.unit.dp
-import androidx.lifecycle.viewmodel.compose.viewModel
-import androidx.navigation.compose.NavHost
-import androidx.navigation.compose.composable
-import androidx.navigation.compose.currentBackStackEntryAsState
-import androidx.navigation.compose.rememberNavController
-import come.stormborntales.notevault.data.local.AppDatabase
-import come.stormborntales.notevault.data.local.entity.NoteEntity
-import come.stormborntales.notevault.data.repository.NoteRepository
-import come.stormborntales.notevault.ui.screens.AddNoteDialog
-import come.stormborntales.notevault.ui.screens.MainScreen
-import come.stormborntales.notevault.ui.screens.NotesScreen
-import come.stormborntales.notevault.ui.screens.SettingsScreen
-import come.stormborntales.notevault.ui.theme.NoteVaultTheme
-import come.stormborntales.notevault.ui.viewmodel.NoteViewModel
-import come.stormborntales.notevault.ui.viewmodel.NoteViewModelFactory
-import kotlinx.coroutines.launch
-
-
-class MainActivity : ComponentActivity() {
-    @OptIn(ExperimentalMaterial3Api::class)
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        val applicationContext = applicationContext
-        val database = AppDatabase.getDatabase(applicationContext)
-        val repository = NoteRepository(database.noteDao())
-        val viewModelFactory = NoteViewModelFactory(repository)
-
-        setContent {
-            NoteVaultTheme {
-                val navController = rememberNavController()
-                val viewModel: NoteViewModel = viewModel(factory = viewModelFactory)
-
-                var selectedUris by remember { mutableStateOf<List<Uri>>(emptyList()) }
-                var showDialog by remember { mutableStateOf(false) }
-                var noteToEdit by remember { mutableStateOf<NoteEntity?>(null) }
-                val drawerState = rememberDrawerState(DrawerValue.Closed)
-                val scope = rememberCoroutineScope()
-
-                val imagePickerLauncher = rememberLauncherForActivityResult(
-                    contract = ActivityResultContracts.OpenMultipleDocuments(),
-                    onResult = { uris ->
-                        if (uris.isNotEmpty()) {
-                            selectedUris = uris
-                            showDialog = true
-                        }
-                    }
-                )
-
-                val openDialog: (NoteEntity?) -> Unit = { note ->
-                    Log.d("EditNote", "NoteEntity: ${note?.title}")
-                    noteToEdit = note
-                    showDialog = true
-                }
-
-                val navItems = listOf(
-                    "Home" to "main",
-                    "Notes" to "notes",
-                    "Einstellungen" to "settings"
-                )
-
-                ModalNavigationDrawer(
-                    drawerState = drawerState,
-                    drawerContent = {
-                        ModalDrawerSheet {
-                            Text("Navigation", modifier = Modifier.padding(16.dp), style = MaterialTheme.typography.titleMedium)
-                            navItems.forEach { (label, route) ->
-                                NavigationDrawerItem(
-                                    label = { Text(label) },
-                                    selected = false,
-                                    onClick = {
-                                        navController.navigate(route) {
-                                            popUpTo(navController.graph.startDestinationId) { saveState = true }
-                                            launchSingleTop = true
-                                            restoreState = true
-                                        }
-                                        scope.launch { drawerState.close() }
-                                    },
-                                    modifier = Modifier.padding(NavigationDrawerItemDefaults.ItemPadding)
-                                )
-                            }
-                        }
-                    }
-                ) {
-                    Scaffold(
-                        topBar = {
-                            var searchQuery by remember { mutableStateOf("") }
-                            var isMenuExpanded by remember { mutableStateOf(false) }
-
-                            val navBackStackEntry by navController.currentBackStackEntryAsState()
-                            val currentRoute = navBackStackEntry?.destination?.route
-
-                            TopAppBar(
-                                title = {
-                                    if(currentRoute == "main") {
-                                        TextField(
-                                            value = searchQuery,
-                                            onValueChange = {
-                                                searchQuery = it
-                                                viewModel.searchQuery.value = it
-                                            },
-                                            placeholder = { Text("Suche...") },
-                                            singleLine = true,
-                                            modifier = Modifier
-                                                .fillMaxWidth()
-                                                .padding(end = 48.dp), // Platz für Avatar
-                                            textStyle = MaterialTheme.typography.bodyLarge,
-                                            colors = TextFieldDefaults.textFieldColors(
-                                                containerColor = Color.Transparent,
-                                                unfocusedIndicatorColor = Color.Transparent,
-                                                focusedIndicatorColor = Color.Transparent
-                                            )
-                                        )
-                                    } else {
-                                        Text("NoteVault")
-                                    }
-                                },
-                                navigationIcon = {
-                                    IconButton(onClick = { scope.launch { drawerState.open() } }) {
-                                        Icon(Icons.Default.Menu, contentDescription = "Menü öffnen")
-                                    }
-                                },
-                                actions = {
-                                    Box {
-                                        IconButton(onClick = { isMenuExpanded = true }) {
-                                            Icon(
-                                                imageVector = Icons.Default.AccountCircle, // Avatar-Icon
-                                                contentDescription = "Benutzerprofil"
-                                            )
-                                        }
-                                        DropdownMenu(
-                                            expanded = isMenuExpanded,
-                                            onDismissRequest = { isMenuExpanded = false }
-                                        ) {
-                                            DropdownMenuItem(
-                                                text = { Text("Profil") },
-                                                onClick = {
-                                                    isMenuExpanded = false
-                                                    // TODO: Navigiere ggf. zu Profilscreen
-                                                }
-                                            )
-                                            DropdownMenuItem(
-                                                text = { Text("Abmelden") },
-                                                onClick = {
-                                                    isMenuExpanded = false
-                                                    // TODO: Logout-Logik
-                                                }
-                                            )
-                                        }
-                                    }
-                                }
-                            )
-                        }
-                    ) { innerPadding ->
-                        NavHost(
-                            navController = navController,
-                            startDestination = "main",
-                            modifier = Modifier.padding(innerPadding)
-                        ) {
-                            composable("main") {
-                                MainScreen(
-                                    viewModel = viewModel,
-                                    onAddNoteClicked = {
-                                        imagePickerLauncher.launch(arrayOf("image/*"))
-                                    },
-                                    onEditNote = openDialog
-                                )
-                            }
-                            composable("settings") {
-                                SettingsScreen()
-                            }
-                            composable("notes") {
-                                NotesScreen()
-                            }
-                        }
-
-                        if (showDialog) {
-                            val context = LocalContext.current
-                            AddNoteDialog(
-                                onDismiss = { showDialog = false },
-                                onSave = { title, composer, year, genre, description ->
-                                    if (noteToEdit == null) {
-                                        viewModel.addNote(
-                                            context = context,
-                                            title = title,
-                                            composer = composer,
-                                            year = year,
-                                            genre = genre,
-                                            description = description,
-                                            selectedUris = selectedUris,
-                                            onDone = { showDialog = false }
-                                        )
-                                    } else {
-                                        viewModel.updateNote(
-                                            editedNote = noteToEdit!!,
-                                            updatedTitle = title,
-                                            updatedComposer = composer,
-                                            updatedYear = year,
-                                            updatedGenre = genre,
-                                            updatedDescription = description,
-                                            onDone = { showDialog = false }
-                                        )
-                                    }
-                                },
-                                initialTitle = noteToEdit?.title ?: "",
-                                initialComposer = noteToEdit?.composer,
-                                initialYear = noteToEdit?.year,
-                                initialGenre = noteToEdit?.genre,
-                                initialDescription = noteToEdit?.description
-                            )
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/data/local/AppDatabase.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/local/AppDatabase.kt
@ -1,35 +0,0 @@
-package come.stormborntales.notevault.data.local
-
-import android.content.Context
-import android.util.Log
-import androidx.room.Database
-import androidx.room.Room
-import androidx.room.RoomDatabase
-import androidx.room.TypeConverters
-import come.stormborntales.notevault.data.local.dao.NoteDao
-import come.stormborntales.notevault.data.local.entity.NoteCollection
-import come.stormborntales.notevault.data.local.entity.NoteEntity
-
-@Database(entities = [NoteEntity::class, NoteCollection::class], version = 1)
-@TypeConverters(UriListConverter::class)
-abstract class AppDatabase : RoomDatabase() {
-    abstract fun noteDao(): NoteDao
-
-    companion object {
-        @Volatile
-        private var INSTANCE: AppDatabase? = null
-
-        fun getDatabase(context: Context): AppDatabase {
-            return INSTANCE ?: synchronized(this) {
-                val instance = Room.databaseBuilder(
-                    context.applicationContext,
-                    AppDatabase::class.java,
-                    "note_database"
-                ).build()
-                INSTANCE = instance
-                Log.d("AppDatabase", "Datenbank erstellt: ${instance.openHelper.writableDatabase}")
-                instance
-            }
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/data/local/UriListConverter.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/local/UriListConverter.kt
@ -1,11 +0,0 @@
-package come.stormborntales.notevault.data.local
-
-import androidx.room.TypeConverter
-
-class UriListConverter {
-    @TypeConverter
-    fun fromList(list: List<String>): String = list.joinToString(",")
-
-    @TypeConverter
-    fun toList(data: String): List<String> = if (data.isBlank()) emptyList() else data.split(",")
-}
--- a/app/src/main/java/come/stormborntales/notevault/data/local/dao/NoteDao.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/local/dao/NoteDao.kt
@ -1,25 +0,0 @@
-package come.stormborntales.notevault.data.local.dao
-
-import androidx.room.Dao
-import androidx.room.Delete
-import androidx.room.Insert
-import androidx.room.OnConflictStrategy
-import androidx.room.Query
-import androidx.room.Update
-import come.stormborntales.notevault.data.local.entity.NoteEntity
-import kotlinx.coroutines.flow.Flow
-
-@Dao
-interface NoteDao {
-    @Query("SELECT * FROM notes")
-    fun getAll(): Flow<List<NoteEntity>>
-
-    @Insert(onConflict = OnConflictStrategy.REPLACE)
-    suspend fun insert(note: NoteEntity)
-
-    @Delete
-    suspend fun delete(note: NoteEntity)
-
-    @Update
-    suspend fun update(note: NoteEntity)
-}
--- a/app/src/main/java/come/stormborntales/notevault/data/local/entity/NoteCollection.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/local/entity/NoteCollection.kt
@ -1,11 +0,0 @@
-package come.stormborntales.notevault.data.local.entity
-
-import androidx.room.Entity
-import androidx.room.PrimaryKey
-
-@Entity("note_collections")
-data class NoteCollection(
-    @PrimaryKey(autoGenerate = true) var id: Int = 0,
-    var name: String,
-    var parentId: Int? = null
-)
--- a/app/src/main/java/come/stormborntales/notevault/data/local/entity/NoteEntity.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/local/entity/NoteEntity.kt
@ -1,24 +0,0 @@
-package come.stormborntales.notevault.data.local.entity
-
-import androidx.room.Entity
-import androidx.room.ForeignKey
-import androidx.room.PrimaryKey
-
-@Entity(tableName = "notes",
-    foreignKeys = [ForeignKey(
-        entity = NoteCollection::class,
-        parentColumns = ["id"],
-        childColumns = ["collectionId"],
-        onDelete = ForeignKey.CASCADE
-    )])
-data class NoteEntity(
-    @PrimaryKey(autoGenerate = true) val id: Int = 0,
-    var title: String,
-    val images: List<String>, // oder String + TypeConverter
-    var composer: String?,
-    var year: Int?,
-    var genre: String?,
-    var description: String?,
-    val imagePreview: String,
-    val collectionId: Int?
-)
--- a/app/src/main/java/come/stormborntales/notevault/data/model/NoteEntry.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/model/NoteEntry.kt
@ -1,10 +0,0 @@
-package come.stormborntales.notevault.data.model
-
-import android.net.Uri
-
-class NoteEntry(
-    val title: String, val images: List<Uri>, val composer: String?, val year: Int?,
-    val genre: String?, val description: String?
-) {
-
-}
--- a/app/src/main/java/come/stormborntales/notevault/data/repository/NoteRepository.kt
+++ b/app/src/main/java/come/stormborntales/notevault/data/repository/NoteRepository.kt
@ -1,14 +0,0 @@
-package come.stormborntales.notevault.data.repository
-
-import come.stormborntales.notevault.data.local.dao.NoteDao
-import come.stormborntales.notevault.data.local.entity.NoteEntity
-import kotlinx.coroutines.flow.Flow
-
-class NoteRepository(private val dao: NoteDao) {
-    val allNotes: Flow<List<NoteEntity>> = dao.getAll()
-
-    suspend fun insert(note: NoteEntity) = dao.insert(note)
-    suspend fun delete(note: NoteEntity) = dao.delete(note)
-
-    suspend fun update(note: NoteEntity) = dao.update(note);
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/screens/AddNoteDialog.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/screens/AddNoteDialog.kt
@ -1,126 +0,0 @@
-package come.stormborntales.notevault.ui.screens
-
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.runtime.*
-import androidx.compose.ui.Modifier
-import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.verticalScroll
-import androidx.compose.material3.*
-import androidx.compose.ui.unit.dp
-
-@Composable
-fun AddNoteDialog(
-    onDismiss: () -> Unit,
-    onSave: (title: String, composer: String?, year: Int?, genre: String?, description: String?) -> Unit,
-    initialTitle: String = "",
-    initialComposer: String? = null,
-    initialYear: Int? = null,
-    initialGenre: String? = null,
-    initialDescription: String? = null
-) {
-    var title by remember { mutableStateOf(initialTitle) }
-    var composer by remember { mutableStateOf(initialComposer ?: "") }
-    var yearText by remember { mutableStateOf(initialYear?.toString() ?: "") }
-    var genre by remember { mutableStateOf(initialGenre ?: "") }
-    var description by remember { mutableStateOf(initialDescription ?: "") }
-    var showTitleError by remember { mutableStateOf(false) }
-
-
-    AlertDialog(
-        onDismissRequest = onDismiss,
-        confirmButton = {
-            TextButton(onClick = {
-                if (title.isBlank()) {
-                    showTitleError = true
-                } else {
-                    val year = yearText.toIntOrNull()
-                    onSave(
-                        title.trim(),
-                        composer.takeIf { it.isNotBlank() },
-                        year,
-                        genre.takeIf { it.isNotBlank() },
-                        description.takeIf { it.isNotBlank() }
-                    )
-                }
-            }) {
-                Text("Speichern")
-            }
-        },
-        dismissButton = {
-            TextButton(onClick = onDismiss) {
-                Text("Abbrechen")
-            }
-        },
-        title = {
-            Text("Notenblatt hinzufügen", style = MaterialTheme.typography.titleLarge)
-        },
-        text = {
-            Column(modifier = Modifier.verticalScroll(rememberScrollState())) {
-                OutlinedTextField(
-                    value = title,
-                    onValueChange = {
-                        title = it
-                        if (it.isNotBlank()) showTitleError = false
-                    },
-                    label = { Text("Titel*") },
-                    isError = showTitleError,
-                    singleLine = true,
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(vertical = 4.dp)
-                )
-                if (showTitleError) {
-                    Text(
-                        "Titel darf nicht leer sein",
-                        color = MaterialTheme.colorScheme.error,
-                        style = MaterialTheme.typography.bodySmall,
-                        modifier = Modifier.padding(start = 16.dp, bottom = 4.dp)
-                    )
-                }
-
-                OutlinedTextField(
-                    value = composer,
-                    onValueChange = { composer = it },
-                    label = { Text("Komponist (optional)") },
-                    singleLine = true,
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(vertical = 4.dp)
-                )
-
-                OutlinedTextField(
-                    value = yearText,
-                    onValueChange = { yearText = it.filter { c -> c.isDigit() } },
-                    label = { Text("Erscheinungsjahr (optional)") },
-                    singleLine = true,
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(vertical = 4.dp)
-                )
-
-                OutlinedTextField(
-                    value = genre,
-                    onValueChange = { genre = it },
-                    label = { Text("Genre (optional)") },
-                    singleLine = true,
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(vertical = 4.dp)
-                )
-
-                OutlinedTextField(
-                    value = description,
-                    onValueChange = { description = it },
-                    label = { Text("Beschreibung (optional)") },
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(vertical = 4.dp),
-                    maxLines = 4
-                )
-            }
-        }
-    )
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/screens/FullScreenViewer.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/screens/FullScreenViewer.kt
@ -1,58 +0,0 @@
-package come.stormborntales.notevault.ui.screens
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.*
-import androidx.compose.foundation.pager.HorizontalPager
-import androidx.compose.foundation.pager.rememberPagerState
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.ArrowBack
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.unit.dp
-import android.net.Uri
-import androidx.compose.foundation.ExperimentalFoundationApi
-import androidx.compose.material.icons.filled.Close
-import androidx.compose.ui.layout.ContentScale
-import kotlinx.coroutines.launch
-
-@OptIn(ExperimentalFoundationApi::class)
-@Composable
-fun FullscreenImageViewer(
-    images: List<Uri>,
-    onClose: () -> Unit
-) {
-    val pagerState = rememberPagerState(pageCount = { images.size })
-
-    Box(modifier = Modifier.fillMaxSize()) {
-        HorizontalPager(state = pagerState) { page ->
-            val context = LocalContext.current
-            val imageBitmap = remember(images[page]) {
-                loadImageBitmap(context, images[page].toString())
-            }
-
-            imageBitmap?.let {
-                Image(
-                    bitmap = it,
-                    contentDescription = "Notenbild",
-                    modifier = Modifier
-                        .fillMaxSize()
-                        .background(Color.Black),
-                    contentScale = ContentScale.Fit
-                )
-            }
-        }
-
-        IconButton(
-            onClick = onClose,
-            modifier = Modifier
-                .align(Alignment.TopStart)
-                .padding(16.dp)
-        ) {
-            Icon(Icons.Default.Close, contentDescription = "Schließen", tint = Color.White)
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/screens/MainScreen.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/screens/MainScreen.kt
@ -1,269 +0,0 @@
-package come.stormborntales.notevault.ui.screens
-
-import android.content.Context
-import android.content.Intent
-import android.graphics.BitmapFactory
-import android.graphics.ImageDecoder
-import android.media.Image
-import android.net.Uri
-import android.util.Log
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.horizontalScroll
-import androidx.compose.foundation.layout.*
-import androidx.compose.foundation.lazy.LazyColumn
-import androidx.compose.foundation.lazy.items
-import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Add
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
-import androidx.compose.runtime.livedata.observeAsState
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.graphics.ImageBitmap
-import androidx.compose.ui.graphics.asImageBitmap
-import androidx.compose.ui.platform.LocalConfiguration
-import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.unit.dp
-import come.stormborntales.notevault.FullscreenImageViewerActivity
-import come.stormborntales.notevault.data.local.entity.NoteEntity
-import come.stormborntales.notevault.data.model.NoteEntry
-import come.stormborntales.notevault.ui.viewmodel.NoteViewModel
-import java.io.InputStream
-import androidx.core.net.toUri
-import androidx.lifecycle.viewmodel.compose.viewModel
-import coil.compose.AsyncImage
-
-fun loadImageBitmap(context: Context, uriString: String): ImageBitmap? {
-    return try {
-        val uri = uriString.toUri()
-        val inputStream: InputStream? = context.contentResolver.openInputStream(uri)
-        val bitmap = BitmapFactory.decodeStream(inputStream)
-        bitmap?.asImageBitmap()
-    } catch (e: Exception) {
-        e.printStackTrace()
-        null
-    }
-}@Composable
-fun NoteCard(note: NoteEntity, onDeleteNote: (NoteEntity) -> Unit, onEditNote: (NoteEntity) -> Unit) {
-    val context = LocalContext.current
-
-    val screenWidth = LocalConfiguration.current.screenWidthDp // Bildschirmbreite in dp
-
-    // Dynamische Bildgröße basierend auf der Bildschirmbreite
-    val imageSize = if (screenWidth < 400) 80.dp else 120.dp
-
-    Card(
-        modifier = Modifier
-            .fillMaxWidth()
-            .padding(vertical = 8.dp),
-        shape = RoundedCornerShape(16.dp),
-        elevation = CardDefaults.cardElevation(defaultElevation = 4.dp),
-    ) {
-        // Responsive Layout: Überprüfen, ob der Bildschirm schmaler als 360 dp ist
-        if (screenWidth < 400) {
-            // Wenn der Bildschirm schmal ist, arrangiere die Elemente vertikal
-            Row(modifier = Modifier.padding(16.dp)) {
-                AsyncImage(
-                    model = note.imagePreview,
-                    contentDescription = "Vorschaubild",
-                    modifier = Modifier
-                        .size(imageSize)
-                        .clip(RoundedCornerShape(12.dp))
-                )
-
-
-                Column(modifier = Modifier.padding(16.dp)) {
-                    Text(
-                        text = note.title,
-                        style = MaterialTheme.typography.titleMedium
-                    )
-
-                    note.composer?.let {
-                        Text("von $it", style = MaterialTheme.typography.labelMedium)
-                    }
-
-                    Spacer(modifier = Modifier.height(4.dp))
-
-                    note.year?.let {
-                        Text("Jahr: $it", style = MaterialTheme.typography.bodySmall)
-                    }
-
-                    note.genre?.let {
-                        Text("Genre: $it", style = MaterialTheme.typography.bodySmall)
-                    }
-
-                    note.description?.let {
-                        Text("Beschreibung: $it", style = MaterialTheme.typography.bodySmall, maxLines = 2)
-                    }
-
-                    Spacer(modifier = Modifier.height(16.dp)) // Abstand zwischen Text und Buttons
-                }
-            }
-            // Buttons unter dem Text
-            Row(
-                horizontalArrangement = Arrangement.spacedBy(8.dp),
-                modifier = Modifier.fillMaxWidth().padding(16.dp),
-            ) {
-                OutlinedButton(
-                    onClick = {
-                        val uris = ArrayList<Uri>()
-                        note.images.forEach { uris.add(it.toUri()) }
-
-                        val intent = Intent(context, FullscreenImageViewerActivity::class.java).apply {
-                            putParcelableArrayListExtra("imageUris", ArrayList(uris))
-                        }
-                        context.startActivity(intent)
-                    },
-                    contentPadding = PaddingValues(horizontal = 12.dp, vertical = 4.dp)
-                ) {
-                    Text("Anzeigen", style = MaterialTheme.typography.labelLarge)
-                }
-
-                OutlinedButton(
-                    onClick = {
-                        onEditNote(note)
-                    },
-                    contentPadding = PaddingValues(horizontal = 12.dp, vertical = 4.dp)
-                ) {
-                    Text("Bearbeiten", style = MaterialTheme.typography.labelLarge)
-                }
-
-                OutlinedButton(
-                    onClick = {
-                        onDeleteNote(note)
-                    },
-                    colors = ButtonDefaults.outlinedButtonColors(
-                        contentColor = MaterialTheme.colorScheme.error
-                    ),
-                    contentPadding = PaddingValues(horizontal = 12.dp, vertical = 4.dp)
-                ) {
-                    Text("Löschen", style = MaterialTheme.typography.labelLarge)
-                }
-            }
-        } else {
-            // Wenn der Bildschirm breiter als 360 dp ist, arrangiere die Elemente nebeneinander
-            Row(modifier = Modifier.padding(16.dp)) {
-                // Linkes Vorschaubild
-                AsyncImage(
-                    model = note.imagePreview,
-                    contentDescription = "Vorschaubild",
-                    modifier = Modifier
-                        .size(imageSize)
-                        .clip(RoundedCornerShape(12.dp))
-                )
-
-                // Rechte Info-Spalte
-                Column(
-                    modifier = Modifier
-                        .weight(1f) // Damit die Spalte den verfügbaren Platz nutzt
-                        .align(Alignment.CenterVertically)
-                        .padding(start = 16.dp)
-                ) {
-                    Text(
-                        text = note.title,
-                        style = MaterialTheme.typography.titleMedium
-                    )
-
-                    note.composer?.let {
-                        Text("von $it", style = MaterialTheme.typography.labelMedium)
-                    }
-
-                    Spacer(modifier = Modifier.height(4.dp))
-
-                    note.year?.let {
-                        Text("Jahr: $it", style = MaterialTheme.typography.bodySmall)
-                    }
-
-                    note.genre?.let {
-                        Text("Genre: $it", style = MaterialTheme.typography.bodySmall)
-                    }
-
-                    note.description?.let {
-                        Text("Beschreibung: $it", style = MaterialTheme.typography.bodySmall, maxLines = 2)
-                    }
-
-                    Spacer(modifier = Modifier.height(8.dp))
-
-                    // Buttons in einer Row anordnen
-                    Row(
-                        horizontalArrangement = Arrangement.spacedBy(8.dp),
-                        modifier = Modifier.fillMaxWidth() // Stellt sicher, dass die Row den gesamten verfügbaren Platz einnimmt
-                    ) {
-                        OutlinedButton(
-                            onClick = {
-                                val uris = ArrayList<Uri>()
-                                note.images.forEach { uris.add(it.toUri()) }
-
-                                val intent = Intent(context, FullscreenImageViewerActivity::class.java).apply {
-                                    putParcelableArrayListExtra("imageUris", ArrayList(uris))
-                                }
-                                context.startActivity(intent)
-                            },
-                            contentPadding = PaddingValues(horizontal = 12.dp, vertical = 4.dp)
-                        ) {
-                            Text("Anzeigen", style = MaterialTheme.typography.labelLarge)
-                        }
-
-                        OutlinedButton(
-                            onClick = {
-                                onEditNote(note)
-                            },
-                            contentPadding = PaddingValues(horizontal = 12.dp, vertical = 4.dp)
-                        ) {
-                            Text("Bearbeiten", style = MaterialTheme.typography.labelLarge)
-                        }
-
-                        OutlinedButton(
-                            onClick = {
-                                onDeleteNote(note)
-                            },
-                            colors = ButtonDefaults.outlinedButtonColors(
-                                contentColor = MaterialTheme.colorScheme.error
-                            ),
-                            contentPadding = PaddingValues(horizontal = 12.dp, vertical = 4.dp)
-                        ) {
-                            Text("Löschen", style = MaterialTheme.typography.labelLarge)
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
-
-
-@OptIn(ExperimentalMaterial3Api::class)
-@Composable
-fun MainScreen(
-    onAddNoteClicked: () -> Unit, // Übergib hier deine Logik für den Import
-    viewModel: NoteViewModel,
-    onEditNote: (NoteEntity) -> Unit
-) {
-    val notes by viewModel.filteredNotes.collectAsState(initial = emptyList())
-    Scaffold(
-        floatingActionButton = {
-            FloatingActionButton(
-                onClick = onAddNoteClicked
-            ) {
-                Icon(Icons.Default.Add, contentDescription = "Neue Noten hinzufügen")
-            }
-        },
-        floatingActionButtonPosition = FabPosition.End
-    ) { innerPadding ->
-        LazyColumn(
-            contentPadding = innerPadding,
-            modifier = Modifier
-                .fillMaxSize()
-                .padding(16.dp)
-        ) {
-            items(notes) { note ->
-                NoteCard(note = note, onDeleteNote = { noteEntity ->
-                    viewModel.deleteNote(noteEntity)
-                }, onEditNote = onEditNote)
-            }
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/screens/NotesBrowser.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/screens/NotesBrowser.kt
@ -1,24 +0,0 @@
-package come.stormborntales.notevault.ui.screens
-
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.Divider
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedButton
-import androidx.compose.material3.Switch
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.unit.dp
-
-
-@Composable
-fun NotesScreen() {
-
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/screens/SettingsScreen.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/screens/SettingsScreen.kt
@ -1,79 +0,0 @@
-package come.stormborntales.notevault.ui.screens
-
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.Divider
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedButton
-import androidx.compose.material3.Switch
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.unit.dp
-
-@Composable
-fun SettingsScreen() {
-    Column(
-        modifier = Modifier
-            .fillMaxSize()
-            .padding(16.dp)
-    ) {
-        Text(
-            text = "Einstellungen",
-            style = MaterialTheme.typography.headlineMedium,
-            modifier = Modifier.padding(bottom = 16.dp)
-        )
-
-        Divider()
-
-        Spacer(modifier = Modifier.height(16.dp))
-
-        // Beispielhafte Einstellung
-        Row(
-            verticalAlignment = Alignment.CenterVertically,
-            modifier = Modifier.fillMaxWidth()
-        ) {
-            Text(
-                text = "Dark Mode",
-                modifier = Modifier.weight(1f),
-                style = MaterialTheme.typography.bodyLarge
-            )
-            Switch(
-                checked = false,
-                onCheckedChange = { /* TODO: Dark Mode aktivieren */ }
-            )
-        }
-
-        Spacer(modifier = Modifier.height(16.dp))
-
-        Row(
-            verticalAlignment = Alignment.CenterVertically,
-            modifier = Modifier.fillMaxWidth()
-        ) {
-            Text(
-                text = "Benachrichtigungen",
-                modifier = Modifier.weight(1f),
-                style = MaterialTheme.typography.bodyLarge
-            )
-            Switch(
-                checked = true,
-                onCheckedChange = { /* TODO: Benachrichtigungseinstellungen */ }
-            )
-        }
-
-        Spacer(modifier = Modifier.height(32.dp))
-
-        OutlinedButton(
-            onClick = { /* TODO: Impressum anzeigen */ },
-            modifier = Modifier.fillMaxWidth()
-        ) {
-            Text("Impressum")
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/theme/Color.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/theme/Color.kt
@ -1,11 +0,0 @@
-package come.stormborntales.notevault.ui.theme
-
-import androidx.compose.ui.graphics.Color
-
-val Purple80 = Color(0xFFD0BCFF)
-val PurpleGrey80 = Color(0xFFCCC2DC)
-val Pink80 = Color(0xFFEFB8C8)
-
-val Purple40 = Color(0xFF6650a4)
-val PurpleGrey40 = Color(0xFF625b71)
-val Pink40 = Color(0xFF7D5260)
--- a/app/src/main/java/come/stormborntales/notevault/ui/theme/Theme.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/theme/Theme.kt
@ -1,58 +0,0 @@
-package come.stormborntales.notevault.ui.theme
-
-import android.app.Activity
-import android.os.Build
-import androidx.compose.foundation.isSystemInDarkTheme
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.darkColorScheme
-import androidx.compose.material3.dynamicDarkColorScheme
-import androidx.compose.material3.dynamicLightColorScheme
-import androidx.compose.material3.lightColorScheme
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.platform.LocalContext
-
-private val DarkColorScheme = darkColorScheme(
-    primary = Purple80,
-    secondary = PurpleGrey80,
-    tertiary = Pink80
-)
-
-private val LightColorScheme = lightColorScheme(
-    primary = Purple40,
-    secondary = PurpleGrey40,
-    tertiary = Pink40
-
-    /* Other default colors to override
-    background = Color(0xFFFFFBFE),
-    surface = Color(0xFFFFFBFE),
-    onPrimary = Color.White,
-    onSecondary = Color.White,
-    onTertiary = Color.White,
-    onBackground = Color(0xFF1C1B1F),
-    onSurface = Color(0xFF1C1B1F),
-    */
-)
-
-@Composable
-fun NoteVaultTheme(
-    darkTheme: Boolean = isSystemInDarkTheme(),
-    // Dynamic color is available on Android 12+
-    dynamicColor: Boolean = true,
-    content: @Composable () -> Unit
-) {
-    val colorScheme = when {
-        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
-            val context = LocalContext.current
-            if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
-        }
-
-        darkTheme -> DarkColorScheme
-        else -> LightColorScheme
-    }
-
-    MaterialTheme(
-        colorScheme = colorScheme,
-        typography = Typography,
-        content = content
-    )
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/theme/Type.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/theme/Type.kt
@ -1,34 +0,0 @@
-package come.stormborntales.notevault.ui.theme
-
-import androidx.compose.material3.Typography
-import androidx.compose.ui.text.TextStyle
-import androidx.compose.ui.text.font.FontFamily
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.unit.sp
-
-// Set of Material typography styles to start with
-val Typography = Typography(
-    bodyLarge = TextStyle(
-        fontFamily = FontFamily.Default,
-        fontWeight = FontWeight.Normal,
-        fontSize = 16.sp,
-        lineHeight = 24.sp,
-        letterSpacing = 0.5.sp
-    )
-    /* Other default text styles to override
-    titleLarge = TextStyle(
-        fontFamily = FontFamily.Default,
-        fontWeight = FontWeight.Normal,
-        fontSize = 22.sp,
-        lineHeight = 28.sp,
-        letterSpacing = 0.sp
-    ),
-    labelSmall = TextStyle(
-        fontFamily = FontFamily.Default,
-        fontWeight = FontWeight.Medium,
-        fontSize = 11.sp,
-        lineHeight = 16.sp,
-        letterSpacing = 0.5.sp
-    )
-    */
-)
--- a/app/src/main/java/come/stormborntales/notevault/ui/viewmodel/NoteViewModel.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/viewmodel/NoteViewModel.kt
@ -1,134 +0,0 @@
-package come.stormborntales.notevault.ui.viewmodel
-
-import android.content.Context
-import android.graphics.Bitmap
-import android.graphics.BitmapFactory
-import android.net.Uri
-import android.util.Log
-import android.webkit.MimeTypeMap
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.asLiveData
-import androidx.lifecycle.viewModelScope
-import come.stormborntales.notevault.data.local.entity.NoteEntity
-import come.stormborntales.notevault.data.repository.NoteRepository
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
-import java.io.File
-import androidx.core.graphics.scale
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
-import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.stateIn
-
-class NoteViewModel(
-    private val repository: NoteRepository,
-) : ViewModel() {
-    // Sucheingabe als StateFlow
-    val searchQuery = MutableStateFlow("")
-
-    // Alle Notizen als Flow aus der Datenbank (NICHT blockierend!)
-    private val allNotes: Flow<List<NoteEntity>> = repository.allNotes
-
-    // Gefilterte Notizen basierend auf Sucheingabe
-    val filteredNotes: StateFlow<List<NoteEntity>> = combine(searchQuery, allNotes) { query, notes ->
-        if (query.isBlank()) {
-            notes
-        } else {
-            notes.filter {
-                it.title.contains(query, ignoreCase = true) ||
-                        it.description?.contains(query, ignoreCase = true) == true
-            }
-        }
-    }.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), emptyList())
-
-
-    fun createPreviewImage(context: Context, uri: Uri): File? {
-       return try {
-           val inputStream = context.contentResolver.openInputStream(uri)
-           val originalBitmap = BitmapFactory.decodeStream(inputStream) ?: return null
-
-           val previewBitmap = originalBitmap.scale(128, 128, false)
-           val previewFile = File(context.filesDir, "preview_${System.currentTimeMillis()}.jpg")
-           previewFile.outputStream().use { out ->
-               previewBitmap.compress(Bitmap.CompressFormat.JPEG, 75, out)
-           }
-           previewFile
-       } catch (e: Exception) {
-           e.printStackTrace()
-           null
-       }
-    }
-
-    fun addNote(context: Context, title: String, composer: String?, year: Int?, genre: String?, description: String?, selectedUris: List<Uri>, onDone:() -> Unit) {
-        viewModelScope.launch(Dispatchers.IO) {
-            val copiedUris = selectedUris.mapNotNull { uri ->
-                try {
-                    val inputStream = context.contentResolver.openInputStream(uri)
-                    val extension = MimeTypeMap.getSingleton()
-                        .getExtensionFromMimeType(context.contentResolver.getType(uri)) ?: "jpg"
-
-                    val outputFile = File(context.filesDir, "note_${System.currentTimeMillis()}.$extension")
-                    inputStream?.use { input ->
-                        outputFile.outputStream().use { output ->
-                            input.copyTo(output)
-                        }
-                    }
-                    Log.d("NoteViewModel", "NoteEntityFile" + outputFile.absolutePath)
-                    Uri.fromFile(outputFile).toString() // speichern als String
-                } catch (e: Exception) {
-                    e.printStackTrace()
-                    null
-                }
-            }
-
-            if (copiedUris.isNotEmpty()) {
-                val preview_image_path = createPreviewImage(context, uri = selectedUris[0])
-
-                val note = NoteEntity(
-                    title = title,
-                    images = copiedUris, // muss als List<String> gespeichert sein
-                    composer = composer,
-                    year = year,
-                    genre = genre,
-                    description = description,
-                    imagePreview = preview_image_path.toString(),
-                    collectionId = null
-                )
-
-                repository.insert(note)
-            }
-
-            onDone()
-        }
-    }
-
-    fun deleteNote(note: NoteEntity) {
-        viewModelScope.launch {
-            repository.delete(note)
-        }
-    }
-
-    fun updateNote(
-        editedNote: NoteEntity,
-        updatedTitle: String,
-        updatedComposer: String?,
-        updatedYear: Int?,
-        updatedGenre: String?,
-        updatedDescription: String?,
-        onDone: () -> Unit
-    ) {
-        viewModelScope.launch {
-            editedNote.title = updatedTitle
-            editedNote.year = updatedYear;
-            editedNote.composer = updatedComposer
-            editedNote.genre = updatedGenre
-            editedNote.description = updatedDescription
-
-            repository.update(editedNote)
-
-            onDone()
-        }
-    }
-}
--- a/app/src/main/java/come/stormborntales/notevault/ui/viewmodel/NoteViewModelFactory.kt
+++ b/app/src/main/java/come/stormborntales/notevault/ui/viewmodel/NoteViewModelFactory.kt
@ -1,17 +0,0 @@
-package come.stormborntales.notevault.ui.viewmodel
-
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
-import come.stormborntales.notevault.data.repository.NoteRepository
-
-class NoteViewModelFactory(
-    private val repository: NoteRepository
-) : ViewModelProvider.Factory {
-    override fun <T : ViewModel> create(modelClass: Class<T>): T {
-        if (modelClass.isAssignableFrom(NoteViewModel::class.java)) {
-            @Suppress("UNCHECKED_CAST")
-            return NoteViewModel(repository) as T
-        }
-        throw IllegalArgumentException("Unknown ViewModel class")
-    }
-}
--- a/app/src/main/res/drawable/delete.xml
+++ b/app/src/main/res/drawable/delete.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="960"
+    android:viewportHeight="960">
+  <path
+      android:pathData="M280,840q-33,0 -56.5,-23.5T200,760v-520h-40v-80h200v-40h240v40h200v80h-40v520q0,33 -23.5,56.5T680,840L280,840ZM680,240L280,240v520h400v-520ZM360,680h80v-360h-80v360ZM520,680h80v-360h-80v360ZM280,240v520,-520Z"
+      android:fillColor="#e8eaed"/>
+</vector>
--- a/app/src/main/res/drawable/dialog_background.xml
+++ b/app/src/main/res/drawable/dialog_background.xml
@ -0,0 +1,6 @@
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <solid android:color="@android:color/white" />
+    <corners android:radius="16dp" />
+    <padding android:left="16dp" android:top="16dp" android:right="16dp" android:bottom="16dp" />
+    <elevation android:height="4dp" />
+</shape>
--- a/app/src/main/res/drawable/edit_24dp_e8eaed_fill0_wght400_grad0_opsz24.xml
+++ b/app/src/main/res/drawable/edit_24dp_e8eaed_fill0_wght400_grad0_opsz24.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="960"
+    android:viewportHeight="960">
+  <path
+      android:pathData="M200,760h57l391,-391 -57,-57 -391,391v57ZM120,840v-170l528,-527q12,-11 26.5,-17t30.5,-6q16,0 31,6t26,18l55,56q12,11 17.5,26t5.5,30q0,16 -5.5,30.5T817,313L290,840L120,840ZM760,256 L704,200 760,256ZM619,341 L591,312 648,369 619,341Z"
+      android:fillColor="#e8eaed"/>
+</vector>
--- a/app/src/main/res/drawable/ic_menu_camera.xml
+++ b/app/src/main/res/drawable/ic_menu_camera.xml
@ -0,0 +1,12 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+            android:fillColor="#FF000000"
+            android:pathData="M12,12m-3.2,0a3.2,3.2 0,1 1,6.4 0a3.2,3.2 0,1 1,-6.4 0"/>
+    <path
+            android:fillColor="#FF000000"
+            android:pathData="M9,2L7.17,4H4c-1.1,0 -2,0.9 -2,2v12c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2V6c0,-1.1 -0.9,-2 -2,-2h-3.17L15,2H9zm3,15c-2.76,0 -5,-2.24 -5,-5s2.24,-5 5,-5 5,2.24 5,5 -2.24,5 -5,5z"/>
+</vector>
--- a/app/src/main/res/drawable/ic_menu_gallery.xml
+++ b/app/src/main/res/drawable/ic_menu_gallery.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+            android:fillColor="#FF000000"
+            android:pathData="M22,16V4c0,-1.1 -0.9,-2 -2,-2H8c-1.1,0 -2,0.9 -2,2v12c0,1.1 0.9,2 2,2h12c1.1,0 2,-0.9 2,-2zm-11,-4l2.03,2.71L16,11l4,5H8l3,-4zM2,6v14c0,1.1 0.9,2 2,2h14v-2H4V6H2z"/>
+</vector>
--- a/app/src/main/res/drawable/ic_menu_slideshow.xml
+++ b/app/src/main/res/drawable/ic_menu_slideshow.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+            android:fillColor="#FF000000"
+            android:pathData="M4,6H2v14c0,1.1 0.9,2 2,2h14v-2H4V6zm16,-4H8c-1.1,0 -2,0.9 -2,2v12c0,1.1 0.9,2 2,2h12c1.1,0 2,-0.9 2,-2V4c0,-1.1 -0.9,-2 -2,-2zm-8,12.5v-9l6,4.5 -6,4.5z"/>
+</vector>
--- a/app/src/main/res/drawable/login.xml
+++ b/app/src/main/res/drawable/login.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="960"
+    android:viewportHeight="960">
+  <path
+      android:pathData="M480,840v-80h280v-560L480,200v-80h280q33,0 56.5,23.5T840,200v560q0,33 -23.5,56.5T760,840L480,840ZM400,680 L345,622 447,520L120,520v-80h327L345,338l55,-58 200,200 -200,200Z"
+      android:fillColor="#e8eaed"/>
+</vector>
--- a/Show More
+++ b/Show More