/*
* Copyright(c) 1997-2001 Id Software, Inc.
* Copyright(c) 2002 The Quakeforge Project.
* Copyright(c) 2006 Quetoo.
*
* 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 <SDL.h>

#include "client.h"

extern dma_t dma;

void paint_audio(void *unused, Uint8 *stream, int len){
	dma.buffer = stream;
	dma.offset += len / (dma.bits / 4);
	S_PaintChannels(dma.offset);
}

qboolean SND_Init(void){
	SDL_AudioSpec desired, obtained;
	int desired_bits;
	
	if(SDL_WasInit(SDL_INIT_EVERYTHING) == 0){
		if(SDL_Init(SDL_INIT_AUDIO) < 0){
			Com_Printf("Couldn't init SDL audio: %s\n", SDL_GetError());
			return false;
		}
	} else if(SDL_WasInit(SDL_INIT_AUDIO) == 0){
		if(SDL_InitSubSystem(SDL_INIT_AUDIO) < 0){
			Com_Printf("Couldn't init SDL audio: %s\n", SDL_GetError());
			return false;
		}
	}
	
	desired_bits = (int)s_bits->value;
	switch(desired_bits){
		case 8:
			desired.format = AUDIO_U8;
			break;
		case 16:
			if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
				desired.format = AUDIO_S16MSB;
			else
				desired.format = AUDIO_S16LSB;
			break;
		default:
			Com_Printf("Unknown number of audio bits: %d\n", desired_bits);
			return false;
	}
	
	desired.channels = (int)s_channels->value;
	if(desired.channels < 1)
		desired.channels = 1;
	else if(desired.channels > 2)
		desired.channels = 2;
	
	desired.freq = *s_rate->string ?  // casting the float is problematic
			atoi(s_rate->string) : 48000;
	
	if(desired.freq == 48000 || desired.freq == 44100)
		desired.samples = 4096;  // set buffer based on rate
	else if(desired.freq == 22050)
		desired.samples = 2048;
	else desired.samples = 1024;
	
	desired.callback = paint_audio;
	
	if(SDL_OpenAudio(&desired, &obtained) < 0){  // open device
		Com_Printf("Couldn't open SDL audio: %s\n", SDL_GetError());
		return false;
	}
	
	switch(obtained.format){  // ensure format is supported
		case AUDIO_U8:
			break;
		case AUDIO_S16LSB:
		case AUDIO_S16MSB:
			if(((obtained.format == AUDIO_S16LSB) &&
					(SDL_BYTEORDER == SDL_LIL_ENDIAN)) ||
					((obtained.format == AUDIO_S16MSB) &&
					(SDL_BYTEORDER == SDL_BIG_ENDIAN))){
				break;
			}
		default:  // unsupported format
			SDL_CloseAudio();
			if(SDL_OpenAudio(&desired, NULL) < 0){
				Com_Printf("Couldn't open SDL audio: %s\n", SDL_GetError());
				return 0;
			}
			memcpy(&obtained, &desired, sizeof(desired));
			break;
	}
	SDL_PauseAudio(0);
	
	// copy obtained to dma struct
	dma.bits = (obtained.format & 0xFF);
	dma.rate = obtained.freq;
	dma.channels = obtained.channels;
	dma.samples = obtained.samples * dma.channels;
	dma.offset = 0;
	dma.chunk = 1;
	dma.buffer = NULL;
	
	return true;
}

int SND_GetDMAPos(void){
	return dma.offset;
}

void SND_Shutdown(void){
	
	SDL_CloseAudio();
	
	if(SDL_WasInit(SDL_INIT_EVERYTHING) == SDL_INIT_AUDIO)
		SDL_Quit();
	else
		SDL_QuitSubSystem(SDL_INIT_AUDIO);
}

void SND_Submit(void){}

void SND_BeginPainting(void){}