#include <iostream>
#include <bits/getopt_core.h>

#include "rendering/wrapper/GLFW.h"
#include "rendering/wrapper/GLWrapper.h"
#include "rendering/wrapper/Window.h"
#include "rendering/Options.h"
#include "gaming-core/utils/Clock.h"
#include "rendering/wrapper/Shader.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;
}

bool parseArgs(int argAmount, char* const* args, Options& options) {
    while(true) {
        switch(getopt(argAmount, args, "fv")) {
            case '?':
                return true;
            case 'f':
                options.fullscreen = true;
                break;
            case 'v':
                options.vsync = true;
                break;
            case -1:
                return false;
        }
    }
}

int main(int argAmount, char* const* args) {
    Options options("Pigine");
    if(parseArgs(argAmount, args, options)) {
        return 0;
    }

    if(GLFW::init()) {
        return 0;
    }

    Size size(800, 480);
    Controller controller;
    Window window(size, controller, options);
    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);

    Clock fps;
    Clock tps;

    static Game game(controller, fps, tps);

    window.show();

    const Clock::Nanos nanosPerTick = 10'000'000;
    Clock::Nanos 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.scale(Vector3(2.0f / size.width, -2.0f / size.height, 1.0f));
        view.translate(Vector3(-1.0f, 1.0f, 0.0f));
        shader.setMatrix("view", view.getValues());

        game.render(static_cast<float> (lag) / nanosPerTick, renderer);
        window.swapBuffers();

        glfwPollEvents();
    }
    return 0;
}