/*
 * Copyright 2017 Yann Weber
 * 
 * This file is part of SndPipe.
 * 
 * SndPipe 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
 * any later version.
 * 
 * SndPipe 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 SndPipe.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <unistd.h>
#include <stdio.h>
#include <getopt.h>
#include <errno.h>

#ifdef SDL2
	#include <SDL2/SDL.h>
#else
	#include <SDL/SDL.h>
	#pragma GCC error "Not supported yet :'(" 
#endif

#define SNDPIPE_LONG_OPT {\
	{"freq", required_argument, 0, 'f'},\
	{"signed", no_argument, 0, 'S'},\
	{"bit-size", required_argument, 0, 'B'},\
	{"endianness", required_argument, 0, 'E'},\
	{"float", no_argument, 0, 'F'},\
	{"channels", required_argument, 0, 'c'},\
	{"samples", required_argument, 0, 's'},\
	{"output", required_argument, 0, 'o'},\
	{"no-sound", no_argument, 0, 'N'},\
	{"verbose", no_argument, 0, 'v'},\
	{"help", no_argument, 0, 'h'},\
	{0,	0, 	0,	0}\
}
#define SNDPIPE_SHORT_OPT "f:SB:E:Fc:s:o:Nvh"
#define SNDPIPE_OPT_HELP {\
	{"Input frequencie (default is 48000)", "FREQ"},\
	{"If given signed numbers are expected (default for 32 bits)", NULL},\
	{"Number of bits per number. One of : 32, 16 and 8 (integers only)",\
		"BIT_COUNT"},\
	{"Number endianess. Accepted values are : LSB, MSB and SYS (system's \
native byte order)", "BYTEORDER"},\
	{"If given, floating point numbers are excepted instead of intergers\
 (32 bits only)",\
		NULL},\
	{"Channels count. 1 for mono, 2 for stereo, ...", "COUNT"},\
	{"Samples per audioframe. Default value is 4096", "INT"},\
	{"Output filename. STDOUT if '-' given", "FILENAME"},\
	{"Don't play sound on soundcard using SDL", NULL},\
	{"Display informations on stderr when given", NULL},\
	{"Print this help and exit", NULL},\
	{"", NULL}\
}

#define SNDPIPE_UNSIGNED 0
#define SNDPIPE_SIGNED	1

#define SNDPIPE_ESYS 0
#define SNDPIPE_ELSB 2
#define SNDPIPE_EMSB 4

#define SNDPIPE_BSZ_8 0
#define SNDPIPE_BSZ_16 8
#define SNDPIPE_BSZ_32 16

#define SNDPIPE_INT32 0
#define SNDPIPE_FLOAT32 32

#define SNDPIPE_SDL_FMT {\
	AUDIO_U8,\
	AUDIO_S8,\
	0,\
	0,\
	0,\
	0,\
	0,\
	0,\
	AUDIO_U16SYS,\
	AUDIO_S16SYS,\
	AUDIO_U16LSB,\
	AUDIO_S16LSB,\
	AUDIO_U16MSB,\
	AUDIO_S16MSB,\
	0,\
	0,\
	AUDIO_S32SYS,\
	AUDIO_F32SYS,\
	AUDIO_S32LSB,\
	AUDIO_F32LSB,\
	AUDIO_S32MSB,\
	AUDIO_F32MSB\
}

static int VERBOSITY = 0;
static int SILENT = 0;

void usage()
{
	static struct option opts[] = SNDPIPE_LONG_OPT;
	static char *help[][2] = SNDPIPE_OPT_HELP;
	size_t i;
	printf("Usage : generator | sndpipe [OPTIONS]\n");
	printf("or : sndpipe [OPTIONS] < file\n");
	printf("\t\n");
	printf("Options list\n");
	i=0;
	while(opts[i].name)
	{
		printf("\t-%c, --%s", opts[i].val, opts[i].name);
		if(opts[i].has_arg == required_argument)
		{
			printf("=%s\n",
				help[i][1]?help[i][1]:"ARG");
		}
		else if(opts[i].has_arg == optional_argument)
		{
			printf("[=%s]\n",
				help[i][1]?help[i][1]:"ARG");
		}
		else
		{
			printf("\n");
		}
		printf("\t\t%s\n\n", help[i][0]);
		i++;
	}
}



void audio_cllbck(void *udata, Uint8 *stream, int len)
{
	int ret;
	while(len)
	{
		if((ret = read(0, stream, len)) == -1)
		{
			perror("Error reading stdin");
			exit(1);
		}

		if (ret == 0)
		{
			fprintf(stderr, "Stdin EOF... Exiting...\n");
			*(int*)udata = 0;
			break;
		}
		
		len -= ret;
	}
	return;
}

int main(int argc, char **argv)
{
	static struct option long_opts[] = SNDPIPE_LONG_OPT;
	static SDL_AudioFormat opt_fmt[] = SNDPIPE_SDL_FMT;
	SDL_AudioSpec want, have;
	SDL_AudioDeviceID dev;
	int running, c, opt_i, ret, fmt_idx;
	short err;

	SDL_memset(&want, 0, sizeof(want));

	want.freq = 48000;
	want.format = AUDIO_U8;
	want.channels = 2;
	want.samples = 4096;
	want.callback = audio_cllbck;
	want.userdata = &running;

	fmt_idx = 0;

	while(1)
	{

		c = getopt_long(argc, argv, SNDPIPE_SHORT_OPT, long_opts, &opt_i);
		if(c == -1)
		{
			break;
		}
		switch(c)
		{
			case 'v':
				VERBOSITY++;
				break;
			case 'f':
				want.freq = atoi(optarg);
				break;
			case 'S':
				fmt_idx |= SNDPIPE_SIGNED;
				break;
			case 'B':
				switch(ret = atoi(optarg))
				{
					case 8:
						fmt_idx |= SNDPIPE_BSZ_8;
						break;
					case 16:
						fmt_idx |= SNDPIPE_BSZ_16;
						break;
					case 32:
						fmt_idx |= SNDPIPE_BSZ_32;
						break;
					default:
						fprintf(stderr, "\
Invalid bits count %d\n", ret);
						err = 1;
						break;
				}
				break;
			case 'E':
				if( !strncmp("LSB", optarg, 4)\
					|| !strncmp("lsb", optarg, 4))
				{
						fmt_idx |= SNDPIPE_ELSB;
				}
				else if(!strncmp("MSB", optarg, 4)\
					|| !strncmp("msb", optarg, 4))
				{
						fmt_idx |= SNDPIPE_EMSB;
				}
				else if(!strncmp("SYS", optarg, 4)\
					|| !strncmp("sys", optarg, 4))
				{
						fmt_idx |= SNDPIPE_ESYS;
				}
				else
				{
						fprintf(stderr, "\
Invalid endianness '%s'\n", optarg);
						err = 1;
				}
				break;
			case 'F':
				fmt_idx |= SNDPIPE_FLOAT32;
				break;
			case 'c':
				want.channels = atoi(optarg);
				if(want.channels < 1)
				{
					fprintf(stderr, "Invalid channel count \
%d\n", want.channels);
					err = 1;
				}
				break;
			case 's':
				want.samples = atoi(optarg);
				break;
			case 'o':
				fprintf(stderr, "\
Ouptut file not implemented yet :'(\n");
				break;
			case 'N':
				SILENT = 1;
				break;
			case 'h':
				usage();
				exit(0);
			default:
				/* ?? */
				err = 1;

		}
	}

	if(err)
	{
		usage();
		exit(1);
	}

	if((fmt_idx & (SNDPIPE_BSZ_32 | SNDPIPE_SIGNED))\
		== (SNDPIPE_BSZ_32| SNDPIPE_SIGNED))
	{
		fmt_idx &= 0xFF - SNDPIPE_SIGNED;
	}
	if(fmt_idx & SNDPIPE_FLOAT32)
	{
		if(!(fmt_idx & SNDPIPE_BSZ_32))
		{
			fprintf(stderr, "Floats only supported for 32 bits.\n\n");
			usage();
			exit(1);
		}
		fmt_idx &= 0xFF - SNDPIPE_FLOAT32;
		fmt_idx |= 1; //correcting index for float32
	}
	if(fmt_idx & (SNDPIPE_ELSB | SNDPIPE_EMSB) \
		&& !(fmt_idx & (SNDPIPE_BSZ_16 | SNDPIPE_BSZ_32)))
	{
		fprintf(stderr,
			"Specifying endianness is not supported for 8-bit\n\n");
		usage();
		exit(1);
	}
	if(fmt_idx > 21)
	{
		fprintf(stderr, "Fatal error : invalid format\n\n");
		exit(2);
	}
	if(err)
	{
		fprintf(stderr, "\n");
		exit(1);
	}
	want.format = opt_fmt[fmt_idx];

	if(!SILENT)
	{
		if(SDL_Init(SDL_INIT_AUDIO ) <0 )
		{
			fprintf(stderr,
				"Unable to initialize SDL : '%s'\n", SDL_GetError());
			return 1;
		}

		dev = SDL_OpenAudioDevice(NULL, 0, &want, &have, 0);
		if(dev == 0)
		{
			fprintf(stderr,
				"Failed to open an audio device : '%s'\n",
				SDL_GetError());
			return 1;
		}
	}
	
	if(!SILENT)
	{
		running = 1;
		SDL_PauseAudioDevice(dev, 0); /* playing */
		while(running)
		{
			SDL_Delay(1);
		}
		SDL_Quit();
	}
}