#include <engine/Backend/Shader.h>
#include <engine/Backend/Camera.h>
#include <engine/Backend/Model.h>

#include <glad/glad.h>
#include <optional>

#include <glm/gtc/matrix_transform.hpp>

namespace game
{
    const int SCREEN_WIDTH = 1366;
    const int SCREEN_HEIGHT = 768;

    std::optional<Shader> shader;
    std::optional<Model> model;
    std::optional<Camera> camera;

    float lastX = SCREEN_WIDTH / 2.0f;
    float lastY = SCREEN_HEIGHT / 2.0f;
    bool firstMouse = true;

    bool Init()
    {
        shader.emplace("assets/shaders/basicVertex.vert", "assets/shaders/basicFragment.frag");
        shader->Use();

        camera.emplace(glm::vec3(0.0f, 0.0f, 0.0f));
        model.emplace("assets/models/sponza/Sponza.gltf");

        return true;
    }

    void PreFrame()
    {
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        shader->Use();

        camera->Update(shader.value(), SCREEN_WIDTH, SCREEN_HEIGHT);
    }

    void Render()
    {
        glm::mat4 modelTransform = glm::mat4(1.0f);
        modelTransform = glm::translate(modelTransform, glm::vec3(0.0f, 0.0f, 0.0f));
        modelTransform = glm::scale(modelTransform, glm::vec3(0.02f, 0.02f, 0.02f));
        shader->setMat4("model", modelTransform);
        model->Draw(shader.value());
    }

    void Update()
    {

    }

    void PostFrame()
    {

    }

    void Cleanup()
    {

    }
}