#include <SDL.h>
#include <SDL_image.h>
#include <stdlib.h>
#include <stdio.h>

SDL_Surface *load_image(char *path, SDL_Surface *screen)
{
	SDL_Surface *surface2 = NULL;
	SDL_Surface *surface = NULL;
	surface = IMG_Load(path);
	if (!surface) {
		fprintf(stderr, "IMG_Load failed: %s\n", IMG_GetError());
		goto error;
	}
	surface2 = SDL_ConvertSurface(surface, screen->format, 0);
	if (!surface2) {
		fprintf(stderr, "SDL_ConvertSurface failed: %s\n", SDL_GetError());
		goto error;
	}
error:
	SDL_FreeSurface(surface);
	return surface2;
}

#define NELEMS(x) (sizeof(x) / sizeof((x)[0]))

int main(void)
{
	SDL_Window *window = NULL;
	SDL_Surface *screen = NULL;
	SDL_Surface *logo = NULL;
	int exit_status = EXIT_FAILURE;
	int img_flags = IMG_INIT_PNG;
	uint8_t colours[][3] = {
		{ 0xFF, 0, 0 },
		{ 0, 0xFF, 0 },
		{ 0, 0, 0xFF },
		{ 0, 0, 0 }
	};
	int i;
	int n;

	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
		fprintf(stderr, "SDL_Init failed: %s\n", SDL_GetError());
		goto error;
	}
	if ((IMG_Init(img_flags) & img_flags) != img_flags) {
		fprintf(stderr, "IMG_Init failed: %s\n", IMG_GetError());
		goto error;
	}
	window = SDL_CreateWindow("SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 0, 0, SDL_WINDOW_FULLSCREEN_DESKTOP);
	if (!window) {
		fprintf(stderr, "SDL_CreateWindow failed: %s\n", SDL_GetError());
		goto error;
	}
	screen = SDL_GetWindowSurface(window);
	if (!screen) {
		fprintf(stderr, "SDL_GetWindowSurface failed: %s\n", SDL_GetError());
		goto error;
	}

	n = (int)NELEMS(colours);

	for (i=0; i<n; ++i) {
		uint8_t *c = colours[i];
		if (SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, c[0], c[1], c[2])) < 0) {
			fprintf(stderr, "SDL_FillRect failed: %s\n", SDL_GetError());
			goto error;
		}
		if (SDL_UpdateWindowSurface(window) < 0) {
			fprintf(stderr, "SDL_UpdateWindowSurface failed: %s\n", SDL_GetError());
			goto error;
		}
		SDL_Delay(100);
	}

	logo = load_image("sdl/logo.png", screen);
	if (!logo) {
		goto error;
	}

	if (SDL_BlitSurface(logo, NULL, screen, NULL) < 0) {
		fprintf(stderr, "SDL_BlitSurface failed: %s\n", SDL_GetError());
		goto error;
	}
	if (SDL_UpdateWindowSurface(window) < 0) {
		fprintf(stderr, "SDL_UpdateWindowSurface failed: %s\n", SDL_GetError());
		goto error;
	}

	SDL_Delay(500);

	exit_status = EXIT_SUCCESS;
error:
	SDL_FreeSurface(logo);
	SDL_FreeSurface(screen);
	SDL_DestroyWindow(window);
	SDL_Quit();
	exit(exit_status);
}