/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

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

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 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

    Lesser General Public License for more details.

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

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

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

    This file written by Ryan C. Gordon (icculus@icculus.org)

*/

#include "SDL_config.h"

/* Output raw audio data to a file. */

#if HAVE_STDIO_H

#include <stdio.h>

#endif

#include "SDL_rwops.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_diskaudio.h"

/* The tag name used by DISK audio */

#define DISKAUD_DRIVER_NAME         "disk"

/* environment variables and defaults. */

#define DISKENVR_OUTFILE         "SDL_DISKAUDIOFILE"

#define DISKDEFAULT_OUTFILE      "sdlaudio.raw"

#define DISKENVR_WRITEDELAY      "SDL_DISKAUDIODELAY"

#define DISKDEFAULT_WRITEDELAY   150

/* Audio driver functions */

static int DISKAUD_OpenAudio(_THIS, SDL_AudioSpec *spec);

static void DISKAUD_WaitAudio(_THIS);

static void DISKAUD_PlayAudio(_THIS);

static Uint8 *DISKAUD_GetAudioBuf(_THIS);

static void DISKAUD_CloseAudio(_THIS);

static const char *DISKAUD_GetOutputFilename(void)

{

	const char *envr = SDL_getenv(DISKENVR_OUTFILE);

	return((envr != NULL) ? envr : DISKDEFAULT_OUTFILE);

}

/* Audio driver bootstrap functions */

static int DISKAUD_Available(void)

{

	const char *envr = SDL_getenv("SDL_AUDIODRIVER");

	if (envr && (SDL_strcmp(envr, DISKAUD_DRIVER_NAME) == 0)) {

		return(1);

	}

	return(0);

}

static void DISKAUD_DeleteDevice(SDL_AudioDevice *device)

{

	SDL_free(device->hidden);

	SDL_free(device);

}

static SDL_AudioDevice *DISKAUD_CreateDevice(int devindex)

{

	SDL_AudioDevice *this;

	const char *envr;

	/* 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));

	envr = SDL_getenv(DISKENVR_WRITEDELAY);

	this->hidden->write_delay = (envr) ? SDL_atoi(envr) : DISKDEFAULT_WRITEDELAY;

	/* Set the function pointers */

	this->OpenAudio = DISKAUD_OpenAudio;

	this->WaitAudio = DISKAUD_WaitAudio;

	this->PlayAudio = DISKAUD_PlayAudio;

	this->GetAudioBuf = DISKAUD_GetAudioBuf;

	this->CloseAudio = DISKAUD_CloseAudio;

	this->free = DISKAUD_DeleteDevice;

	return this;

}

AudioBootStrap DISKAUD_bootstrap = {

	DISKAUD_DRIVER_NAME, "direct-to-disk audio",

	DISKAUD_Available, DISKAUD_CreateDevice

};

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

static void DISKAUD_WaitAudio(_THIS)

{

	SDL_Delay(this->hidden->write_delay);

}

static void DISKAUD_PlayAudio(_THIS)

{

	int written;

	/* Write the audio data */

	written = SDL_RWwrite(this->hidden->output,

                        this->hidden->mixbuf, 1,

                        this->hidden->mixlen);

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

	if ( (Uint32)written != this->hidden->mixlen ) {

		this->enabled = 0;

	}

#ifdef DEBUG_AUDIO

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

#endif

}

static Uint8 *DISKAUD_GetAudioBuf(_THIS)

{

	return(this->hidden->mixbuf);

}

static void DISKAUD_CloseAudio(_THIS)

{

	if ( this->hidden->mixbuf != NULL ) {

		SDL_FreeAudioMem(this->hidden->mixbuf);

		this->hidden->mixbuf = NULL;

	}

	if ( this->hidden->output != NULL ) {

		SDL_RWclose(this->hidden->output);

		this->hidden->output = NULL;

	}

}

static int DISKAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)

{

	const char *fname = DISKAUD_GetOutputFilename();

	/* Open the audio device */

	this->hidden->output = SDL_RWFromFile(fname, "wb");

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

		return(-1);

	}

#if HAVE_STDIO_H

	fprintf(stderr, "WARNING: You are using the SDL disk writer"

                    " audio driver!\n Writing to file [%s].\n", fname);

#endif

	/* Allocate mixing buffer */

	this->hidden->mixlen = spec->size;

	this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);

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

		return(-1);

	}

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

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

	return(0);

}