//
// Created by sebastian on 24.12.25.
//

#include "Renderer.h"

#include <ranges>

#include "../core/Application.h"
#include "../layer/entities/Light.h"
#include "../toolbox/MathUtils.h"
#include "glad/glad.h"
#include "glm/ext/matrix_clip_space.hpp"
#include "model/TexturedModel.h"


void Renderer::prepare(const Camera& camera, const Light& light, glm::mat4 projectionMatrix) {
    const glm::mat4 viewMatrix = MathUtils::createViewMatrix(camera);
    staticShader.start();
    staticShader.loadLight(light.getPosition(), light.getColor());
    staticShader.loadViewMatrix(viewMatrix);
    staticShader.loadProjectionMatrix(projectionMatrix);
}


void Renderer::renderEntities(const std::unordered_map<TexturedModel *, std::vector<std::unique_ptr<Entity>>>& entities) {

    for (const auto& [texturedModel, batch] : entities) {
       for (const auto& subModel : texturedModel->getSubModels()) {
           prepareTexturedModel(subModel);
           for (const auto& entity : batch) {
               prepareInstance(*entity);
               glDrawElements(GL_TRIANGLES, subModel.rawModel->vertexCount, GL_UNSIGNED_INT, 0);
           }

           unbindTexturedModel();
       }
    }
}

void Renderer::prepareTexturedModel(const SubModel &subModel) {
    auto rawModel = subModel.rawModel;
    glBindVertexArray(rawModel->vaoID);
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);
    glEnableVertexAttribArray(2);

    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, subModel.texture->getTextureID());
}

void Renderer::unbindTexturedModel() {
    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);
    glDisableVertexAttribArray(2);
    glBindVertexArray(0);
}

void Renderer::prepareInstance(const Entity &entity) {
    glm::mat4 transformationMatrix = MathUtils::createTransformationMatrix(entity.getPosition(), entity.getRotX(), entity.getRotY(), entity.getRotZ(), entity.getScale());
    staticShader.loadTransformationMatrix(transformationMatrix);

    if (entity.getRenderState()) {
        staticShader.loadGhostColor(entity.getRenderState()->ghostColor);
        staticShader.loadGhostMode(entity.getRenderState()->ghostMode);
        staticShader.loadPulse(entity.getRenderState()->pulse);
    }
}

void Renderer::finalizeFrame() {
    staticShader.stop();
}