#include <SDL2/SDL.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <stdbool.h>


void FOSDLAudioCallback(void* userdata, Uint8* buffer, int len);

int main(int argc, char* argv[])
{

    int screen_width = 128;
    int screen_height = 64;
    int i;
    int num_audio_dev;
    int audio_dev_id;
    int quit;

    SDL_Window *window = NULL;
    SDL_Surface *screen = NULL;
    SDL_AudioSpec spec_desired;
    SDL_AudioSpec spec_received;
    SDL_AudioDeviceID audiodev;
    SDL_Event event;


	if (SDL_Init(SDL_INIT_EVERYTHING) < 0)
	{
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "SDL_Init(): %s\n", SDL_GetError());
		exit(1);
	}
    atexit(SDL_Quit);

    /* Handling audio devices */
    num_audio_dev = SDL_GetNumAudioDevices(false);
    for (i = 0; i < num_audio_dev; ++i) {
        SDL_Log("Audio device %d: %s", i, SDL_GetAudioDeviceName(i, 0));
    }

    fprintf(stdout, "Which audio device to open? "); 
    scanf("%d", &audio_dev_id);
    fprintf(stdout, "\nDevice %d : %s choosen\n", audio_dev_id, SDL_GetAudioDeviceName(audio_dev_id, 0)); 

    SDL_zero(spec_desired);
	spec_desired.freq = 22050;
	spec_desired.format = AUDIO_S16LSB;
	spec_desired.channels = 1;
	spec_desired.samples = 8192;
	spec_desired.callback = FOSDLAudioCallback;
	spec_desired.userdata = NULL;

    audiodev = SDL_OpenAudioDevice(SDL_GetAudioDeviceName(audio_dev_id, 0), 0, &spec_desired, &spec_received, SDL_AUDIO_ALLOW_FORMAT_CHANGE);
    if(!audiodev) {
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                     "SDL_OpenAudioDevice(): %s\n", SDL_GetError());
		exit(1);
    }

    if(spec_desired.format != spec_received.format)
    {
        SDL_Log("Format requested not available\n");
    }

    fflush(stdout);
    fflush(stderr);

	window = SDL_CreateWindow("Soundz!", 0, 0, screen_width, screen_height, SDL_WINDOW_SHOWN);
	if (!window)
	{
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_CreateWindow: %s\n", SDL_GetError());
		exit(1);
	}

	SDL_PauseAudioDevice(audiodev, 0);

    screen = SDL_GetWindowSurface(window);

    quit = 0;
    while(!quit)
    {

        while(SDL_PollEvent(&event))
        {
            switch(event.type)
            {
                case SDL_QUIT: quit = 1 ; break;
                case SDL_KEYDOWN: switch(event.key.keysym.sym)
                {
                    case SDLK_ESCAPE: quit = 1; break;
                }
            }
        }

        //surface->pixels

    }

	SDL_Log("Terminating normally.\n");
    SDL_CloseAudioDevice(audiodev);
	return 0;
}

void FOSDLAudioCallback(void* userdata, Uint8* buffer, int len)
{
    fprintf(stdout, "%d\n", len);
    fflush(stdout);
	for (size_t index = 0; index < len; index++)
	{
		buffer[index] = rand() % 256;

	}
}