/* 
   rdesktop: A Remote Desktop Protocol client.
   Sound Channel Process Functions - Open Sound System
   Copyright (C) Matthew Chapman 2003
   Copyright (C) GuoJunBo guojunbo@ict.ac.cn 2003

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "rdesktop.h"
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/soundcard.h>

#define MAX_QUEUE	10

int g_dsp_fd;
BOOL g_dsp_busy;

static struct audio_packet
{
	struct stream s;
	uint16 tick;
	uint8 index;
} packet_queue[MAX_QUEUE];
static unsigned int queue_hi, queue_lo;

BOOL
wave_out_open(void)
{
	char *dsp_dev = "/dev/dsp";

	if ((g_dsp_fd = open(dsp_dev, O_WRONLY | O_NONBLOCK)) == -1)
	{
		perror(dsp_dev);
		return False;
	}

	/* Non-blocking so that user interface is responsive */
	fcntl(g_dsp_fd, F_SETFL, fcntl(g_dsp_fd, F_GETFL) | O_NONBLOCK);
	return True;
}

void
wave_out_close(void)
{
	close(g_dsp_fd);
}

BOOL
wave_out_format_supported(WAVEFORMATEX * pwfx)
{
	if (pwfx->wFormatTag != WAVE_FORMAT_PCM)
		return False;
	if ((pwfx->nChannels != 1) && (pwfx->nChannels != 2))
		return False;
	if ((pwfx->wBitsPerSample != 8) && (pwfx->wBitsPerSample != 16))
		return False;

	return True;
}

BOOL
wave_out_set_format(WAVEFORMATEX * pwfx)
{
	int speed, channels, format;

	ioctl(g_dsp_fd, SNDCTL_DSP_RESET, NULL);
	ioctl(g_dsp_fd, SNDCTL_DSP_SYNC, NULL);

	if (pwfx->wBitsPerSample == 8)
		format = AFMT_U8;
	else if (pwfx->wBitsPerSample == 16)
		format = AFMT_S16_LE;

	if (ioctl(g_dsp_fd, SNDCTL_DSP_SETFMT, &format) == -1)
	{
		perror("SNDCTL_DSP_SETFMT");
		close(g_dsp_fd);
		return False;
	}

	channels = pwfx->nChannels;
	if (ioctl(g_dsp_fd, SNDCTL_DSP_CHANNELS, &channels) == -1)
	{
		perror("SNDCTL_DSP_CHANNELS");
		close(g_dsp_fd);
		return False;
	}

	speed = pwfx->nSamplesPerSec;
	if (ioctl(g_dsp_fd, SNDCTL_DSP_SPEED, &speed) == -1)
	{
		perror("SNDCTL_DSP_SPEED");
		close(g_dsp_fd);
		return False;
	}

	return True;
}

void
wave_out_volume(uint16 left, uint16 right)
{
	uint32 volume;

	volume = left / (65536 / 100);
	volume |= right / (65536 / 100) << 8;
	if (ioctl(g_dsp_fd, MIXER_WRITE(SOUND_MIXER_PCM), &volume) == -1)
	{
		perror("MIXER_WRITE(SOUND_MIXER_PCM)");
		return;
	}
}

void
wave_out_write(STREAM s, uint16 tick, uint8 index)
{
	struct audio_packet *packet = &packet_queue[queue_hi];
	unsigned int next_hi = (queue_hi + 1) % MAX_QUEUE;

	if (next_hi == queue_lo)
	{
		error("No space to queue audio packet\n");
		return;
	}

	queue_hi = next_hi;

	packet->s = *s;
	packet->tick = tick;
	packet->index = index;
	packet->s.p += 4;

	/* we steal the data buffer from s, give it a new one */
	s->data = malloc(s->size);

	if (!g_dsp_busy)
		wave_out_play();
}

void
wave_out_play(void)
{
	struct audio_packet *packet;
	ssize_t len;
	STREAM out;

	while (1)
	{
		if (queue_lo == queue_hi)
		{
			g_dsp_busy = 0;
			return;
		}

		packet = &packet_queue[queue_lo];
		out = &packet->s;

		len = write(g_dsp_fd, out->p, out->end - out->p);
		if (len == -1)
		{
			if (errno != EWOULDBLOCK)
				perror("write audio");
			g_dsp_busy = 1;
			return;
		}

		out->p += len;
		if (out->p == out->end)
		{
			rdpsnd_send_completion(packet->tick, packet->index);
			free(out->data);
			queue_lo = (queue_lo + 1) % MAX_QUEUE;
		}
	}

}