#include <SDL.h>
#include <iostream>
#include <memory>
#include "app.hpp"

#ifdef EMSCRIPTEN
#include <emscripten.h>
#endif

#include "gl.hpp"

static SDL_Window *s_window = nullptr;
static SDL_GLContext s_context = nullptr;
static bool s_quit = false;
static std::unique_ptr<App> s_app;

static bool InitSDL()
{
    if (SDL_Init(SDL_INIT_VIDEO) != 0)
    {
        std::cerr << "SDL_Init Error: " << SDL_GetError() << std::endl;
        return false;
    }

    s_window = SDL_CreateWindow("PortalGame", 100, 100, 640, 480, SDL_WINDOW_SHOWN | SDL_WINDOW_MAXIMIZED | SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
    if (!s_window)
    {
        std::cerr << "SDL_CreateWindow Error: " << SDL_GetError() << std::endl;
        SDL_Quit();
        return false;
    }

    return true;
}

static bool InitGL()
{
#ifdef EMSCRIPTEN
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
#else
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
#endif

    s_context = SDL_GL_CreateContext(s_window);
    if (!s_context)
    {
        std::cerr << "SDL_GL_CreateContext Error: " << SDL_GetError() << std::endl;
        return false;
    }

    // Make context current
    if (SDL_GL_MakeCurrent(s_window, s_context) != 0)
    {
        std::cerr << "SDL_GL_MakeCurrent Error: " << SDL_GetError() << std::endl;
        SDL_GL_DeleteContext(s_context);
        return false;
    }

#ifndef EMSCRIPTEN
	// Initialize GLAD
    if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress))
    {
        std::cerr << "Failed to initialize GLAD" << std::endl;
        SDL_GL_DeleteContext(s_context);
        return false;
	}
#endif

    return true;
}

static void ShutdownGL()
{
    if (s_context)
    {
        SDL_GL_DeleteContext(s_context);
        s_context = nullptr;
    }
}

static void ShutdownSDL()
{
    if (s_window)
    {
        SDL_DestroyWindow(s_window);
        s_window = nullptr;
    }
    SDL_Quit();
}

static void PollEvents()
{
    SDL_Event event;
    while (SDL_PollEvent(&event))
    {
        if (event.type == SDL_QUIT)
        {
            s_quit = true;
            return;
        }
    }
}

static void Frame()
{
    Uint32 current_time = SDL_GetTicks();
    s_app->SetTime(current_time / 1000.0f); // Set time in seconds
    PollEvents();
    s_app->Frame();
    SDL_GL_SwapWindow(s_window);
}

int main(int argc, char *argv[])
{
    if (!InitSDL())
    {
        return 1;
    }

    if (!InitGL())
    {
        ShutdownSDL();
        return 1;
    }

    s_app = std::make_unique<App>();

#ifdef EMSCRIPTEN
    emscripten_set_main_loop(Frame, 0, true);
#else
    while (!s_quit)
    {
        Frame();
    }

    s_app.reset();

    ShutdownGL();
    ShutdownSDL();
#endif
    return 0;
}