#include <iostream>

#include "rendering/wrapper/GLFWWrapper.h"
#include "rendering/wrapper/GLWrapper.h"
#include "rendering/WindowSize.h"
#include "rendering/wrapper/Window.h"
#include "utils/Clock.h"
#include "rendering/wrapper/Shader.h"
#include "input/Controller.h"
#include "rendering/Renderer.h"
#include "Game.h"

bool initGLEW() {
    GLenum err = glewInit();
    if(err != GLEW_OK) {
        std::cout << "could not initialize GLEW: " << glewGetErrorString(err) << "\n";
        return true;
    }
    std::cout << "using GLEW " << glewGetString(GLEW_VERSION) << "\n";
    return false;
}

void initCallbacks(Window& w, WindowSize& size) {
    static WindowSize& cSize = size;
    w.setFramebufferSizeCallback([](GLFWwindow*, int newWidth, int newHeight) {
        glViewport(0, 0, newWidth, newHeight);
        cSize.width = newWidth;
        cSize.height = newHeight;
    });
}

int main() {
    if(GLFWWrapper::hasError()) {
        return 0;
    }
    
    WindowSize size(800, 480);
    Window window(size, "Test");
    if(window.hasError() || initGLEW()) {
        return 0;
    }
    
    Shader shader("resources/shader/vertex.vs", "resources/shader/fragment.fs");
    if(shader.hasError()) {
        return 0;
    }
    
    Renderer renderer(size, shader);
    
    Controller controller;
    Clock fps;
    Clock tps;
    
    static Game game(controller, fps, tps);
    
    initCallbacks(window, size);
    window.show();
    
    const u64 nanosPerTick = 10'000'000;
    u64 lag = 0;
    while(!window.shouldClose() && game.isRunning()) {
        GLWrapper::checkAndPrintError("GL-Error");

        lag += fps.update();
        while(lag >= nanosPerTick) {
            lag -= nanosPerTick;
            tps.update();
            controller.tick();
            game.tick();
        }
        
        Matrix view;
        view.translate(-1.0f, 1.0f);
        view.scale(2.0f / size.width, -2.0f / size.height);
        shader.setMatrix("view", view.getValues());
        
        game.render((float) lag / nanosPerTick, renderer);
        window.swapBuffers();
        
        glfwPollEvents();
    }
    return 0;
}