#include "gl3w.h"
#include <SDL2/SDL.h>
#include <iostream>
#include <ft2build.h>
#include FT_FREETYPE_H

using namespace std;

#define WIDTH   500
#define HEIGHT  500

static FT_Library ft;
static FT_Face face;

void init(void)
{
    glClearColor (0.0, 0.0, 0.0, 0.0);
}

void display(SDL_Window * window)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    SDL_GL_SwapWindow(window);
}

int main(int argc, char *argv[])
{
    if (SDL_Init(SDL_INIT_VIDEO))
    {
        cerr << "Failed to initialize SDL!" << endl;
        return 1;
    }

    atexit(SDL_Quit);

    SDL_Window * window = SDL_CreateWindow(argv[0],
                                           SDL_WINDOWPOS_UNDEFINED,
                                           SDL_WINDOWPOS_UNDEFINED,
                                           WIDTH,
                                           HEIGHT,
                                           SDL_WINDOW_OPENGL);
    if (!window)
    {
        cerr << "Failed to create window!" << endl;
        SDL_Quit();
        return 2;
    }

    SDL_GLContext gl_context = SDL_GL_CreateContext(window);

    if (gl3wInit() != 0)
    {
        cerr << "Failed to gl3wInit()" << endl;
        SDL_Quit();
        return 2;
    }

    if (!gl3wIsSupported(3, 0))
    {
        cerr << "OpenGL 3.0 is not supported!" << endl;
        SDL_Quit();
        return 2;
    }

    if (FT_Init_FreeType(&ft) != 0)
    {
        cerr << "Could not FT_Init_FreeType()" << endl;
        return 2;
    }

    if (FT_New_Face(ft, "/usr/share/fonts/truetype/freefont/FreeMono.ttf", 0, &face) != 0)
    {
        cerr << "Could not load FreeMono.ttf" << endl;
        return 2;
    }

    FT_Set_Pixel_Sizes(face, 0, 20);

    init();
    display(window);
    SDL_Event event;
    while (SDL_WaitEvent(&event))
    {
        if (event.type == SDL_QUIT)
            break;
        else if (event.type == SDL_KEYDOWN)
        {
            if (event.key.keysym.sym == SDLK_ESCAPE)
                break;
            if (event.key.keysym.sym == SDLK_RETURN)
                display(window);
        }
    }
}