/*
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, snd_inited;

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

qboolean SNDDMA_Init (void)
{
	int	rc, fmt, tmp, i, caps;
	char	*s;
	struct	audio_buf_info	info;

	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
	if ((s = getenv("QUAKE_SOUND_SAMPLEBITS")))
		shm->samplebits = Q_atoi(s);
	else if ((i = COM_CheckParm("-sndbits")) && i + 1 < com_argc)
		shm->samplebits = Q_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;
	}

	if ((s = getenv("QUAKE_SOUND_SPEED")))
		shm->speed = Q_atoi(s);
	else if ((i = COM_CheckParm("-sndspeed")) && i + 1 < com_argc)
		shm->speed = Q_atoi(com_argv[i+1]);
	else if (s_khz.value == 44)
		shm->speed = 44100;
	else if (s_khz.value == 22)
		shm->speed = 22050;
	else
	{
		for (i=0 ; i<sizeof(tryrates)/4 ; i++)
			if (!ioctl(audio_fd, SNDCTL_DSP_SPEED, &tryrates[i]))
				break;
		shm->speed = tryrates[i];
	}

	if ((s = getenv("QUAKE_SOUND_CHANNELS")))
		shm->channels = Q_atoi(s);
	else if ((i = COM_CheckParm("-sndmono")))
		shm->channels = 1;
	else if ((i = COM_CheckParm("-sndstereo")))
		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)
{
}
