/*
Copyright (C) 1996-1997 Id Software, Inc.

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/shm.h>
#include <sys/wait.h>
#include <linux/soundcard.h>
#include <stdio.h>
#include "quakedef.h"

int audio_fd;
int snd_inited;

static int tryrates[] = { 11025, 22051, 44100, 8000 };

qboolean SNDDMA_Init (void)
{

	int rc;
	int fmt;
	int tmp;
	int i;
	char *s;
	struct audio_buf_info info;
	int caps;
	
	snd_inited = 0;
	
// open /dev/dsp, confirm capability to mmap, and get size of dma buffer

	audio_fd = open ("/dev/dsp", O_RDWR);
	if (audio_fd < 0)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not open /dev/dsp\n");
		return 0;
	}
	
	rc = ioctl (audio_fd, SNDCTL_DSP_RESET, 0);
	if (rc < 0)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not reset /dev/dsp\n");
		close (audio_fd);
		return 0;
	}
	
	if (ioctl (audio_fd, SNDCTL_DSP_GETCAPS, &caps) == -1)
	{
		perror ("/dev/dsp");
		Con_Printf ("Sound driver too old\n");
		close (audio_fd);
		return 0;
	}
	
	if (! (caps & DSP_CAP_TRIGGER) || ! (caps & DSP_CAP_MMAP))
	{
		Con_Printf ("Sorry but your soundcard can't do this\n");
		close (audio_fd);
		return 0;
	}
	
	if (ioctl (audio_fd, SNDCTL_DSP_GETOSPACE, &info) == -1)
	{
		perror ("GETOSPACE");
		Con_Printf ("Um, can't do GETOSPACE?\n");
		close (audio_fd);
		return 0;
	}
	
	shm = &sn;
	shm->splitbuffer = 0;
	
// set sample bits & speed

	s = getenv ("QUAKE_SOUND_SAMPLEBITS");
	if (s) shm->samplebits = atoi (s);
	else if ( (i = COM_CheckParm ("-sndbits")) != 0)
		shm->samplebits = atoi (com_argv[i+1]);
	if (shm->samplebits != 16 && shm->samplebits != 8)
	{
		ioctl (audio_fd, SNDCTL_DSP_GETFMTS, &fmt);
		if (fmt & AFMT_S16_LE) shm->samplebits = 16;
		else if (fmt & AFMT_U8) shm->samplebits = 8;
	}
	
	s = getenv ("QUAKE_SOUND_SPEED");
	if (s) shm->speed = atoi (s);
	else if ( (i = COM_CheckParm ("-sndspeed")) != 0)
		shm->speed = atoi (com_argv[i+1]);
	else
	{
		for (i = 0 ; i < sizeof (tryrates) / 4 ; i++)
			if (!ioctl (audio_fd, SNDCTL_DSP_SPEED, &tryrates[i])) break;
		shm->speed = tryrates[i];
	}
	
	s = getenv ("QUAKE_SOUND_CHANNELS");
	if (s) shm->channels = atoi (s);
	else if ( (i = COM_CheckParm ("-sndmono")) != 0)
		shm->channels = 1;
	else if ( (i = COM_CheckParm ("-sndstereo")) != 0)
		shm->channels = 2;
	else shm->channels = 2;
	
	shm->samples = info.fragstotal * info.fragsize / (shm->samplebits / 8);
	shm->submission_chunk = 1;
	
// memory map the dma buffer

	shm->buffer = (unsigned char *) mmap (NULL, info.fragstotal
										  * info.fragsize, PROT_WRITE, MAP_FILE | MAP_SHARED, audio_fd, 0);
	if (!shm->buffer || shm->buffer == (unsigned char *) - 1)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not mmap /dev/dsp\n");
		close (audio_fd);
		return 0;
	}
	
	tmp = 0;
	if (shm->channels == 2)
		tmp = 1;
	rc = ioctl (audio_fd, SNDCTL_DSP_STEREO, &tmp);
	if (rc < 0)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not set /dev/dsp to stereo=%d", shm->channels);
		close (audio_fd);
		return 0;
	}
	if (tmp)
		shm->channels = 2;
	else
		shm->channels = 1;
		
	rc = ioctl (audio_fd, SNDCTL_DSP_SPEED, &shm->speed);
	if (rc < 0)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not set /dev/dsp speed to %d", shm->speed);
		close (audio_fd);
		return 0;
	}
	
	if (shm->samplebits == 16)
	{
		rc = AFMT_S16_LE;
		rc = ioctl (audio_fd, SNDCTL_DSP_SETFMT, &rc);
		if (rc < 0)
		{
			perror ("/dev/dsp");
			Con_Printf ("Could not support 16-bit data.  Try 8-bit.\n");
			close (audio_fd);
			return 0;
		}
	}
	else if (shm->samplebits == 8)
	{
		rc = AFMT_U8;
		rc = ioctl (audio_fd, SNDCTL_DSP_SETFMT, &rc);
		if (rc < 0)
		{
			perror ("/dev/dsp");
			Con_Printf ("Could not support 8-bit data.\n");
			close (audio_fd);
			return 0;
		}
	}
	else
	{
		perror ("/dev/dsp");
		Con_Printf ("%d-bit sound not supported.", shm->samplebits);
		close (audio_fd);
		return 0;
	}
	
// toggle the trigger & start her up

	tmp = 0;
	rc  = ioctl (audio_fd, SNDCTL_DSP_SETTRIGGER, &tmp);
	if (rc < 0)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not toggle.\n");
		close (audio_fd);
		return 0;
	}
	tmp = PCM_ENABLE_OUTPUT;
	rc = ioctl (audio_fd, SNDCTL_DSP_SETTRIGGER, &tmp);
	if (rc < 0)
	{
		perror ("/dev/dsp");
		Con_Printf ("Could not toggle.\n");
		close (audio_fd);
		return 0;
	}
	
	shm->samplepos = 0;
	
	snd_inited = 1;
	return 1;
	
}

int SNDDMA_GetDMAPos (void)
{

	struct count_info count;
	
	if (!snd_inited) return 0;
	
	if (ioctl (audio_fd, SNDCTL_DSP_GETOPTR, &count) == -1)
	{
		perror ("/dev/dsp");
		Con_Printf ("Uh, sound dead.\n");
		close (audio_fd);
		snd_inited = 0;
		return 0;
	}
//	shm->samplepos = (count.bytes / (shm->samplebits / 8)) & (shm->samples-1);
//	fprintf(stderr, "%d    \r", count.ptr);
	shm->samplepos = count.ptr / (shm->samplebits / 8);
	
	return shm->samplepos;
	
}

void SNDDMA_Shutdown (void)
{
	if (snd_inited)
	{
		close (audio_fd);
		snd_inited = 0;
	}
}

/*
==============
SNDDMA_Submit

Send sound to device if buffer isn't really the dma buffer
===============
*/
void SNDDMA_Submit (void)
{
}

