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

#include <alsa/asoundlib.h>

#include "sndfile.h"
#include "fmt.h"

/*
 * gcc -O2 -o playit-alsa playit-alsa.c -I.. -I../src/include -DHAVE_CONFIG_H -lm `pkg-config alsa --cflags --libs` -s ../src/libplayit.a
 */

song_t * song_load_it(const char *file)
{
	slurp_t	*s;
	song_t	*song;

	s = slurp(file, NULL, 0);
	if (!s) {
		printf("failed to open \"%s\"\n", file);
		goto _fail;
	}

	song = csf_allocate();
	if (!song) {
		printf("failed to allocate song\n");
		goto _fail_slurp;
	}

	if (fmt_it_load_song(song, s, 0) != LOAD_SUCCESS)
		goto _fail_song;

	unslurp(s);

	return song;

_fail_song:
	csf_free(song);
_fail_slurp:
	unslurp(s);
_fail:
	return NULL;
}


static snd_pcm_t * alsa_open(const char *dev)
{
	snd_pcm_hw_params_t	*hw_params;
	snd_pcm_sw_params_t	*sw_params;
	int			err;
	unsigned int		rate = 44100;
	snd_pcm_t		*pcm;

	if((err = snd_pcm_open(&pcm, dev, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
		fprintf(stderr, "cannot open audio device %s (%s)\n",
			 dev,
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_hw_params_malloc(&hw_params)) < 0) {
		fprintf(stderr, "cannot allocate hardware parameter structure(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_hw_params_any(pcm, hw_params)) < 0) {
		fprintf(stderr, "cannot initialize hardware parameter structure(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_hw_params_set_access(pcm, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
		fprintf(stderr, "cannot set access type(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_hw_params_set_format(pcm, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) {
		fprintf(stderr, "cannot set sample format(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_hw_params_set_rate_near(pcm, hw_params, &rate, 0)) < 0) {
		fprintf(stderr, "cannot set sample rate(%s)\n",
			 snd_strerror(err));
		return NULL;
	}
		
	if((err = snd_pcm_hw_params_set_channels(pcm, hw_params, 2)) < 0) {
		fprintf(stderr, "cannot set channel count(%s)\n",
			 snd_strerror(err));
		return NULL;
	}
		
	if((err = snd_pcm_hw_params(pcm, hw_params)) < 0) {
		fprintf(stderr, "cannot set parameters(%s)\n",
			 snd_strerror(err));
		return NULL;
	}
		
	snd_pcm_hw_params_free(hw_params);

	if((err = snd_pcm_sw_params_malloc(&sw_params)) < 0) {
		fprintf(stderr, "cannot allocate software parameters structure(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_sw_params_current(pcm, sw_params)) < 0) {
		fprintf(stderr, "cannot initialize software parameters structure(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_sw_params_set_avail_min(pcm, sw_params, 4096)) < 0) {
		fprintf(stderr, "cannot set minimum available count(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_sw_params_set_start_threshold(pcm, sw_params, 0U)) < 0) {
		fprintf(stderr, "cannot set start mode(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_sw_params(pcm, sw_params)) < 0) {
		fprintf(stderr, "cannot set software parameters(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	if((err = snd_pcm_prepare(pcm)) < 0) {
		fprintf(stderr, "cannot prepare audio interface for use(%s)\n",
			 snd_strerror(err));
		return NULL;
	}

	return pcm;
}


static void alsa_close(snd_pcm_t *pcm)
{
	snd_pcm_close(pcm);
}


int main(int argc, const char *argv[])
{
	song_t		*song;
	uint8_t		buf[8192];
	int		len;
	snd_pcm_t	*pcm;

	if (argc != 2) {
		printf("usage: %s song.it\n", argv[0]);
		goto _fail;
	}

	song = song_load_it(argv[1]);
	if (!song) {
		printf("failed to load song!\n");
		goto _fail;
	}

	if (!(pcm = alsa_open("default"))) {
		printf("Failed to open ALSA device\n");
		goto _fail_song;
	}

	csf_set_current_order(song, 0);
	song->repeat_count = 0;
	song->buffer_count = 0;
	song->stop_at_order = -1;
	song->stop_at_row = -1;
	song->flags &= ~(SONG_PAUSED | SONG_PATTERNLOOP | SONG_ENDREACHED);
	csf_reset_playmarks(song);
	csf_set_resampling_mode(song, SRCMODE_LINEAR);
	csf_set_wave_config(song, 44100, 16, 2);

	while ((len = csf_read(song, buf, sizeof(buf)))) {
		int	err;

		if ((err = snd_pcm_writei(pcm, buf, len)) < 0) {
			fprintf (stderr, "write failed (%s)\n", snd_strerror(err));
			break;
		}
	}

	alsa_close(pcm);

	return EXIT_SUCCESS;

_fail_song:
	/* TODO cleanup song */

_fail:
	return EXIT_FAILURE;
}