/*
===========================================================================

Return to Castle Wolfenstein multiplayer GPL Source Code
Copyright (C) 1999-2010 id Software LLC, a ZeniMax Media company. 

This file is part of the Return to Castle Wolfenstein multiplayer GPL Source Code (“RTCW MP Source Code”).  

RTCW MP Source Code 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 3 of the License, or
(at your option) any later version.

RTCW MP Source Code 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 RTCW MP Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the RTCW MP Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the RTCW MP Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 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>
#ifdef __linux__ // rb0101023 - guard this
#include <linux/soundcard.h>
#endif
#ifdef __FreeBSD__ // rb0101023 - added
#include <sys/soundcard.h>
#endif
#include <stdio.h>

#include "../game/q_shared.h"
#include "../client/snd_local.h"

int audio_fd;
int snd_inited = 0;

cvar_t *sndbits;
cvar_t *sndspeed;
cvar_t *sndchannels;

cvar_t *snddevice;

/* Some devices may work only with 48000 */
static int tryrates[] = { 22050, 11025, 44100, 48000, 8000 };

static qboolean use_custom_memset = qfalse;
// show_bug.cgi?id=371
void Snd_Memset( void* dest, const int val, const size_t count ) {
	int *pDest;
	int i, iterate;

	if ( !use_custom_memset ) {
		Com_Memset( dest,val,count );
		return;
	}
	iterate = count / sizeof( int );
	pDest = (int*)dest;
	for ( i = 0; i < iterate; i++ )
	{
		pDest[i] = val;
	}
}

qboolean SNDDMA_Init( void ) {
	int rc;
	int fmt;
	int tmp;
	int i;
	// char *s; // bk001204 - unused
	struct audio_buf_info info;
	int caps;
	extern uid_t saved_euid;

	if ( snd_inited ) {
		return 1;
	}

	if ( !snddevice ) {
		sndbits = Cvar_Get( "sndbits", "16", CVAR_ARCHIVE );
		sndspeed = Cvar_Get( "sndspeed", "0", CVAR_ARCHIVE );
		sndchannels = Cvar_Get( "sndchannels", "2", CVAR_ARCHIVE );
		snddevice = Cvar_Get( "snddevice", "/dev/dsp", CVAR_ARCHIVE );
	}

	// open /dev/dsp, confirm capability to mmap, and get size of dma buffer
	if ( !audio_fd ) {
		seteuid( saved_euid );

		audio_fd = open( snddevice->string, O_RDWR );

		seteuid( getuid() );

		if ( audio_fd < 0 ) {
			perror( snddevice->string );
			Com_Printf( "Could not open %s\n", snddevice->string );
			return 0;
		}
	}

	if ( ioctl( audio_fd, SNDCTL_DSP_GETCAPS, &caps ) == -1 ) {
		perror( snddevice->string );
		Com_Printf( "Sound driver too old\n" );
		close( audio_fd );
		return 0;
	}

	if ( !( caps & DSP_CAP_TRIGGER ) || !( caps & DSP_CAP_MMAP ) ) {
		Com_Printf( "Sorry but your soundcard can't do this\n" );
		close( audio_fd );
		return 0;
	}


	/* SNDCTL_DSP_GETOSPACE moved to be called later */

	// set sample bits & speed
	dma.samplebits = (int)sndbits->value;
	if ( dma.samplebits != 16 && dma.samplebits != 8 ) {
		ioctl( audio_fd, SNDCTL_DSP_GETFMTS, &fmt );
		if ( fmt & AFMT_S16_LE ) {
			dma.samplebits = 16;
		} else if ( fmt & AFMT_U8 ) {
			dma.samplebits = 8;
		}
	}

	dma.speed = (int)sndspeed->value;
	if ( !dma.speed ) {
		for ( i = 0 ; i < sizeof( tryrates ) / 4 ; i++ )
			if ( !ioctl( audio_fd, SNDCTL_DSP_SPEED, &tryrates[i] ) ) {
				break;
			}
		dma.speed = tryrates[i];
	}

	dma.channels = (int)sndchannels->value;
	if ( dma.channels < 1 || dma.channels > 2 ) {
		dma.channels = 2;
	}

/*  mmap() call moved forward */

	tmp = 0;
	if ( dma.channels == 2 ) {
		tmp = 1;
	}
	rc = ioctl( audio_fd, SNDCTL_DSP_STEREO, &tmp );
	if ( rc < 0 ) {
		perror( snddevice->string );
		Com_Printf( "Could not set %s to stereo=%d", snddevice->string, dma.channels );
		close( audio_fd );
		return 0;
	}

	if ( tmp ) {
		dma.channels = 2;
	} else {
		dma.channels = 1;
	}

	rc = ioctl( audio_fd, SNDCTL_DSP_SPEED, &dma.speed );
	if ( rc < 0 ) {
		perror( snddevice->string );
		Com_Printf( "Could not set %s speed to %d", snddevice->string, dma.speed );
		close( audio_fd );
		return 0;
	}

	if ( dma.samplebits == 16 ) {
		rc = AFMT_S16_LE;
		rc = ioctl( audio_fd, SNDCTL_DSP_SETFMT, &rc );
		if ( rc < 0 ) {
			perror( snddevice->string );
			Com_Printf( "Could not support 16-bit data.  Try 8-bit.\n" );
			close( audio_fd );
			return 0;
		}
	} else if ( dma.samplebits == 8 ) {
		rc = AFMT_U8;
		rc = ioctl( audio_fd, SNDCTL_DSP_SETFMT, &rc );
		if ( rc < 0 ) {
			perror( snddevice->string );
			Com_Printf( "Could not support 8-bit data.\n" );
			close( audio_fd );
			return 0;
		}
	} else {
		perror( snddevice->string );
		Com_Printf( "%d-bit sound not supported.", dma.samplebits );
		close( audio_fd );
		return 0;
	}

	if ( ioctl( audio_fd, SNDCTL_DSP_GETOSPACE, &info ) == -1 ) {
		perror( "GETOSPACE" );
		Com_Printf( "Um, can't do GETOSPACE?\n" );
		close( audio_fd );
		return 0;
	}

	dma.samples = info.fragstotal * info.fragsize / ( dma.samplebits / 8 );
	dma.submission_chunk = 1;

	// memory map the dma buffer
	// TTimo PROT_READ
	// show_bug.cgi?id=371
	// checking Alsa bug, doesn't allow dma alloc with PROT_READ?

	// 12-24-2001
	// reopening bug, PROT_WRITE|PROT_READ can kill some other drivers
	// we will just default to C implementation for everyone from now on

/*
	if (!dma.buffer)
		dma.buffer = (unsigned char *) mmap(NULL, info.fragstotal
			* info.fragsize, PROT_WRITE|PROT_READ, MAP_FILE|MAP_SHARED, audio_fd, 0);
*/
	dma.buffer = NULL;

	if ( dma.buffer == NULL ) {
//    Com_Printf("Could not mmap dma buffer PROT_WRITE|PROT_READ\n");
//    Com_Printf("trying mmap PROT_WRITE (with associated better compatibility / less performance code)\n");
		dma.buffer = (unsigned char *) mmap( NULL, info.fragstotal
											 * info.fragsize, PROT_WRITE, MAP_FILE | MAP_SHARED, audio_fd, 0 );
		// LordHavoc MAP_FAILED is a bad value to have outside init code
		if (dma.buffer == MAP_FAILED)
			dma.buffer = NULL;
		// NOTE TTimo could add a variable to force using regular memset on systems that are known to be safe
		use_custom_memset = qtrue;
	}

	if ( dma.buffer == NULL ) {
		perror( snddevice->string );
		Com_Printf( "Could not mmap %s\n", snddevice->string );
		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( snddevice->string );
		Com_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( snddevice->string );
		Com_Printf( "Could not toggle.\n" );
		close( audio_fd );

		return 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( snddevice->string );
		Com_Printf( "Uh, sound dead.\n" );
		close( audio_fd );
		snd_inited = 0;
		return 0;
	}
	return count.ptr / ( dma.samplebits / 8 );
}

void SNDDMA_Shutdown( void ) {
}

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

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

void SNDDMA_BeginPainting( void ) {
}