/**
 * Trying to set some parameters for ALSA.
 *
 * Code from: http://equalarea.com/paul/alsa-audio.html
 *
 */

#include <alsa/asoundlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <math.h>

#define PCM_DEVICE "default"

int main(int argc, char **argv)
{
	unsigned int pcm;
	snd_pcm_t *pcm_handle;
	snd_pcm_hw_params_t *params;

	char test[5];

	if(pcm = snd_pcm_open(&pcm_handle, PCM_DEVICE, SND_PCM_STREAM_PLAYBACK, 0) < 0) {
		printf("ERROR: Can't open \"%s\" PCM device. %s\n", PCM_DEVICE, snd_strerror(pcm));

		return 1;
	}

	snd_pcm_hw_params_alloca(&params);

	snd_pcm_hw_params_any(pcm_handle, params);

	if(pcm = snd_pcm_hw_params_set_access(pcm_handle, params, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
		printf("ERROR: Can't set interleaved mode. %s\n", snd_strerror(pcm));

		return 1;
	}

	if(pcm = snd_pcm_hw_params_set_format(pcm_handle, params, SND_PCM_FORMAT_FLOAT) < 0) {
		printf("ERROR: Can't set format. %s\n", snd_strerror(pcm));

		return 1;
	}

	int channels = 2;
	if(pcm = snd_pcm_hw_params_set_channels(pcm_handle, params, channels) < 0) {
		printf("ERROR: Can't set channels number. %s\n", snd_strerror(pcm));

		return 1;
	}

	int rate = 44100;
	if(pcm = snd_pcm_hw_params_set_rate_near(pcm_handle, params, &rate, 0) < 0) {
		printf("ERROR: Can't set rate. %s\n", snd_strerror(pcm));

		return 1;
	}

	printf("PCM name: '%s'\n", snd_pcm_name(pcm_handle));
	printf("PCM state: %s\n", snd_pcm_state_name(snd_pcm_state(pcm_handle)));

	int ch;
	snd_pcm_hw_params_get_channels(params, &ch);

	if(ch > 1) {
		printf("Channels: %i, stereo\n", ch);
	}
	else if(ch == 1) {
		printf("Channels: %i, mono\n", ch);
	}

	snd_pcm_hw_params_get_rate(params, &ch, 0);
	printf("Rate: %d bps\n", ch);

	int dir;
	snd_pcm_uframes_t frames = 1024;

	printf("Attempting to set frames to %d\n", frames);

	snd_pcm_hw_params_set_period_size_near(pcm_handle, params, &frames, &dir);

	snd_pcm_hw_params_get_period_size(params, &frames, 0);

	printf("Frames is now: %zd\n", frames);

	snd_pcm_hw_params_get_period_time(params, &ch, NULL);

	int buffer_size = 4096;

	printf("Attempting to set the buffer size to: %d\n", buffer_size);

	snd_pcm_hw_params_set_buffer_size(pcm_handle, params, buffer_size);

	if(pcm = snd_pcm_hw_params(pcm_handle, params) < 0) {
		printf("ERROR: Can't set harware parameters. %s\n", snd_strerror(pcm));

		return 1;
	}

	snd_pcm_uframes_t temp;

	snd_pcm_hw_params_get_buffer_size(params, &temp);

	printf("Buffer size is now: %d\n", temp);

	snd_pcm_drain(pcm_handle);
	snd_pcm_close(pcm_handle);

	return 0;
}