/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Library General Public

    License as published by the Free Software Foundation; either

    version 2 of the License, or (at your option) any later version.

    This library 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

    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public

    License along with this library; if not, write to the Free

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

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

/*

 * Driver for native OpenBSD/NetBSD audio(4).

 * vedge@vedge.com.ar.

 */

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/time.h>

#include <sys/ioctl.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/audioio.h>

#include "SDL_timer.h"

#include "SDL_audio.h"

#include "../SDL_audiomem.h"

#include "../SDL_audio_c.h"

#include "../SDL_audiodev_c.h"

#include "SDL_bsdaudio.h"

/* The tag name used by NetBSD/OpenBSD audio */

#ifdef __NetBSD__

#define BSD_AUDIO_DRIVER_NAME         "netbsd"

#define BSD_AUDIO_DRIVER_DESC         "Native NetBSD audio"

#else

#define BSD_AUDIO_DRIVER_NAME         "openbsd"

#define BSD_AUDIO_DRIVER_DESC         "Native OpenBSD audio"

#endif

/* Open the audio device for playback, and don't block if busy */

/* #define USE_BLOCKING_WRITES */

/* Use timer for synchronization */

/* #define USE_TIMER_SYNC */

/* #define DEBUG_AUDIO */

/* #define DEBUG_AUDIO_STREAM */

#ifdef USE_BLOCKING_WRITES

#define OPEN_FLAGS	O_WRONLY

#else

#define OPEN_FLAGS	(O_WRONLY|O_NONBLOCK)

#endif

/* Audio driver functions */

static void OBSD_WaitAudio(_THIS);

static int OBSD_OpenAudio(_THIS, SDL_AudioSpec *spec);

static void OBSD_PlayAudio(_THIS);

static Uint8 *OBSD_GetAudioBuf(_THIS);

static void OBSD_CloseAudio(_THIS);

#ifdef DEBUG_AUDIO

static void OBSD_Status(_THIS);

#endif

/* Audio driver bootstrap functions */

static int

Audio_Available(void)

{

    int fd;

    int available;

    available = 0;

    fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0);

    if(fd >= 0) {

	available = 1;

	close(fd);

    }

    return(available);

}

static void

Audio_DeleteDevice(SDL_AudioDevice *device)

{

    SDL_free(device->hidden);

    SDL_free(device);

}

static SDL_AudioDevice

*Audio_CreateDevice(int devindex)

{

    SDL_AudioDevice *this;

    /* Initialize all variables that we clean on shutdown */

    this = (SDL_AudioDevice*)SDL_malloc(sizeof(SDL_AudioDevice));

    if(this) {

	SDL_memset(this, 0, (sizeof *this));

	this->hidden =

	    (struct SDL_PrivateAudioData*)SDL_malloc((sizeof *this->hidden));

    }

    if((this == NULL) || (this->hidden == NULL)) {

	SDL_OutOfMemory();

	if(this) SDL_free(this);

	return(0);

    }

    SDL_memset(this->hidden, 0, (sizeof *this->hidden));

    audio_fd = -1;

    /* Set the function pointers */

    this->OpenAudio = OBSD_OpenAudio;

    this->WaitAudio = OBSD_WaitAudio;

    this->PlayAudio = OBSD_PlayAudio;

    this->GetAudioBuf = OBSD_GetAudioBuf;

    this->CloseAudio = OBSD_CloseAudio;

    this->free = Audio_DeleteDevice;

    return this;

}

AudioBootStrap BSD_AUDIO_bootstrap = {

	BSD_AUDIO_DRIVER_NAME, BSD_AUDIO_DRIVER_DESC,

	Audio_Available, Audio_CreateDevice

};

/* This function waits until it is possible to write a full sound buffer */

static void

OBSD_WaitAudio(_THIS)

{

#ifndef USE_BLOCKING_WRITES /* Not necessary when using blocking writes */

	/* See if we need to use timed audio synchronization */

	if ( frame_ticks ) {

		/* Use timer for general audio synchronization */

		Sint32 ticks;

		ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS;

		if ( ticks > 0 ) {

			SDL_Delay(ticks);

		}

	} else {

		/* Use select() for audio synchronization */

		fd_set fdset;

		struct timeval timeout;

		FD_ZERO(&fdset);

		FD_SET(audio_fd, &fdset);

		timeout.tv_sec = 10;

		timeout.tv_usec = 0;

#ifdef DEBUG_AUDIO

		fprintf(stderr, "Waiting for audio to get ready\n");

#endif

		if ( select(audio_fd+1, NULL, &fdset, NULL, &timeout) <= 0 ) {

			const char *message =

			"Audio timeout - buggy audio driver? (disabled)";

			/* In general we should never print to the screen,

			   but in this case we have no other way of letting

			   the user know what happened.

			*/

			fprintf(stderr, "SDL: %s\n", message);

			this->enabled = 0;

			/* Don't try to close - may hang */

			audio_fd = -1;

#ifdef DEBUG_AUDIO

			fprintf(stderr, "Done disabling audio\n");

#endif

		}

#ifdef DEBUG_AUDIO

		fprintf(stderr, "Ready!\n");

#endif

	}

#endif /* !USE_BLOCKING_WRITES */

}

static void

OBSD_PlayAudio(_THIS)

{

	int written, p=0;

	/* Write the audio data, checking for EAGAIN on broken audio drivers */

	do {

		written = write(audio_fd, &mixbuf[p], mixlen-p);

		if (written>0)

		   p += written;

		if (written == -1 && errno != 0 && errno != EAGAIN && errno != EINTR)

		{

		   /* Non recoverable error has occurred. It should be reported!!! */

		   perror("audio");

		   break;

		}

		if ( p < written || ((written < 0) && ((errno == 0) || (errno == EAGAIN))) ) {

			SDL_Delay(1);	/* Let a little CPU time go by */

		}

	} while ( p < written );

	/* If timer synchronization is enabled, set the next write frame */

	if ( frame_ticks ) {

		next_frame += frame_ticks;

	}

	/* If we couldn't write, assume fatal error for now */

	if ( written < 0 ) {

		this->enabled = 0;

	}

#ifdef DEBUG_AUDIO

	fprintf(stderr, "Wrote %d bytes of audio data\n", written);

#endif

}

static Uint8

*OBSD_GetAudioBuf(_THIS)

{

    return(mixbuf);

}

static void

OBSD_CloseAudio(_THIS)

{

    if(mixbuf != NULL) {

	SDL_FreeAudioMem(mixbuf);

	mixbuf = NULL;

    }

    if(audio_fd >= 0) {

	close(audio_fd);

	audio_fd = -1;

    }

}

#ifdef DEBUG_AUDIO

void

OBSD_Status(_THIS)

{

    audio_info_t info;

    if(ioctl(audio_fd, AUDIO_GETINFO, &info) < 0) {

	fprintf(stderr,"AUDIO_GETINFO failed.\n");

	return;

    }

    fprintf(stderr,"\n"

"[play/record info]\n"

"buffer size	:   %d bytes\n"

"sample rate	:   %i Hz\n"

"channels	:   %i\n"

"precision	:   %i-bit\n"

"encoding	:   0x%x\n"

"seek		:   %i\n"

"sample count	:   %i\n"

"EOF count	:   %i\n"

"paused		:   %s\n"

"error occured	:   %s\n"

"waiting		:   %s\n"

"active		:   %s\n"

"",

    info.play.buffer_size,

    info.play.sample_rate,

    info.play.channels,

    info.play.precision,

    info.play.encoding,

    info.play.seek,

    info.play.samples,

    info.play.eof,

    info.play.pause ? "yes" : "no",

    info.play.error ? "yes" : "no",

    info.play.waiting ? "yes" : "no",

    info.play.active ? "yes": "no");

    fprintf(stderr,"\n"

"[audio info]\n"

"monitor_gain	:   %i\n"

"hw block size	:   %d bytes\n"

"hi watermark	:   %i\n"

"lo watermark	:   %i\n"

"audio mode	:   %s\n"

"",  

    info.monitor_gain,

    info.blocksize,

    info.hiwat, info.lowat,

    (info.mode == AUMODE_PLAY) ? "PLAY"

    : (info.mode = AUMODE_RECORD) ? "RECORD"

    : (info.mode == AUMODE_PLAY_ALL ? "PLAY_ALL"

    : "?"));

}

#endif /* DEBUG_AUDIO */

static int

OBSD_OpenAudio(_THIS, SDL_AudioSpec *spec)

{

    char audiodev[64];

    Uint16 format;

    audio_info_t info;

    AUDIO_INITINFO(&info);

    /* Calculate the final parameters for this audio specification */

    SDL_CalculateAudioSpec(spec);

#ifdef USE_TIMER_SYNC

    frame_ticks = 0.0;

#endif

    /* Open the audio device */

    audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0);

    if(audio_fd < 0) {

	SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));

	return(-1);

    }

    /* Set to play mode */

    info.mode = AUMODE_PLAY;

    if(ioctl(audio_fd, AUDIO_SETINFO, &info) < 0) {

	SDL_SetError("Couldn't put device into play mode");

	return(-1);

    }

    mixbuf = NULL;

    AUDIO_INITINFO(&info);

    for (format = SDL_FirstAudioFormat(spec->format); 

    	format; format = SDL_NextAudioFormat())

    {

	switch(format) {

	case AUDIO_U8:

	    info.play.encoding = AUDIO_ENCODING_ULINEAR;

	    info.play.precision = 8;

	    break;

	case AUDIO_S8:

	    info.play.encoding = AUDIO_ENCODING_SLINEAR;

	    info.play.precision = 8;

	    break;

	case AUDIO_S16LSB:

	    info.play.encoding = AUDIO_ENCODING_SLINEAR_LE;

	    info.play.precision = 16;

	    break;

	case AUDIO_S16MSB:

	    info.play.encoding = AUDIO_ENCODING_SLINEAR_BE;

	    info.play.precision = 16;

	    break;

	case AUDIO_U16LSB:

	    info.play.encoding = AUDIO_ENCODING_ULINEAR_LE;

	    info.play.precision = 16;

	    break;

	case AUDIO_U16MSB:

	    info.play.encoding = AUDIO_ENCODING_ULINEAR_BE;

	    info.play.precision = 16;

	    break;

	default:

	    continue;

	}

	if (ioctl(audio_fd, AUDIO_SETINFO, &info) == 0)

	    break;

    }

    if(!format) {

	SDL_SetError("No supported encoding for 0x%x", spec->format);

	return(-1);

    }

    spec->format = format;

    AUDIO_INITINFO(&info);

    info.play.channels = spec->channels;

    if (ioctl(audio_fd, AUDIO_SETINFO, &info) == -1)

    	spec->channels = 1;

    AUDIO_INITINFO(&info);

    info.play.sample_rate = spec->freq;

    info.blocksize = spec->size;

    info.hiwat = 5;

    info.lowat = 3;

    (void)ioctl(audio_fd, AUDIO_SETINFO, &info);

    (void)ioctl(audio_fd, AUDIO_GETINFO, &info);

    spec->freq  = info.play.sample_rate;

    /* Allocate mixing buffer */

    mixlen = spec->size;

    mixbuf = (Uint8*)SDL_AllocAudioMem(mixlen);

    if(mixbuf == NULL) {

	return(-1);

    }

    SDL_memset(mixbuf, spec->silence, spec->size);

    /* Get the parent process id (we're the parent of the audio thread) */

    parent = getpid();

#ifdef DEBUG_AUDIO

    OBSD_Status(this);

#endif

    /* We're ready to rock and roll. :-) */

    return(0);

}