//=========================================================================
// FILENAME	: tagutils-wav.c
// DESCRIPTION	: WAV metadata reader
//=========================================================================
// Copyright (c) 2009 NETGEAR, Inc. All Rights Reserved.
// based on software from Ron Pedde's FireFly Media Server project
//=========================================================================

/*
 * 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
 */

#define GET_WAV_INT32(p) ((((uint32_t)((p)[3])) << 24) |   \
			  (((uint32_t)((p)[2])) << 16) |   \
			  (((uint32_t)((p)[1])) << 8) |	   \
			  (((uint32_t)((p)[0]))))

#define GET_WAV_INT16(p) ((((uint32_t)((p)[1])) << 8) |	   \
			  (((uint32_t)((p)[0]))))

static int
_get_wavtags(char *filename, struct song_metadata *psong)
{
	int fd;
	uint32_t len;
	unsigned char hdr[12];
	unsigned char fmt[16];
	uint32_t chunk_data_length;
	uint32_t format_data_length = 0;
	uint32_t compression_code = 0;
	uint32_t channel_count = 0;
	uint32_t sample_rate = 0;
	uint32_t sample_bit_length = 0;
	uint32_t bit_rate;
	uint32_t data_length = 0;
	uint32_t sec, ms;

	uint32_t current_offset;
	uint32_t block_len;

	int found_fmt = 0;
	int found_data = 0;

	//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Getting WAV file info\n");

	if(!(fd = open(filename, O_RDONLY)))
	{
		DPRINTF(E_WARN, L_SCANNER, "Could not create file handle\n");
		return -1;
	}

	len = 12;
	if(!(len = read(fd, hdr, len)) || (len != 12))
	{
		DPRINTF(E_WARN, L_SCANNER, "Could not read wav header from %s\n", filename);
		close(fd);
		return -1;
	}

	/* I've found some wav files that have INFO tags
	 * in them... */
	if(strncmp((char*)hdr + 0, "RIFF", 4) ||
	   strncmp((char*)hdr + 8, "WAVE", 4))
	{
		DPRINTF(E_WARN, L_SCANNER, "Invalid wav header in %s\n", filename);
		close(fd);
		return -1;
	}

	chunk_data_length = GET_WAV_INT32(hdr + 4);

	/* now, walk through the chunks */
	current_offset = 12;
	while(!found_fmt && !found_data)
	{
		len = 8;
		if(!(len = read(fd, hdr, len)) || (len != 8))
		{
			close(fd);
			DPRINTF(E_WARN, L_SCANNER, "Error reading block: %s\n", filename);
			return -1;
		}

		block_len = GET_WAV_INT32(hdr + 4);

		//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Read block %02x%02x%02x%02x (%c%c%c%c) of "
		//        "size %08x\n",hdr[0],hdr[1],hdr[2],hdr[3],
		//        hdr[0],hdr[1],hdr[2],hdr[3],block_len);

		if(block_len < 0)
		{
			close(fd);
			DPRINTF(E_WARN, L_SCANNER, "Bad block len: %s\n", filename);
			return -1;
		}

		if(strncmp((char*)&hdr, "fmt ", 4) == 0)
		{
			found_fmt = 1;
			//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Found 'fmt ' header\n");
			len = 16;
			if(!read(fd, fmt, len) || (len != 16))
			{
				close(fd);
				DPRINTF(E_WARN, L_SCANNER, "Bad .wav file: can't read fmt: %s\n",
					filename);
				return -1;
			}

			format_data_length = block_len;
			compression_code = GET_WAV_INT16(fmt);
			channel_count = GET_WAV_INT16(fmt + 2);
			sample_rate = GET_WAV_INT32(fmt + 4);
			sample_bit_length = GET_WAV_INT16(fmt + 14);
			//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Compression code: %d\n",compression_code);
			//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Channel count:    %d\n",channel_count);
			//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Sample Rate:      %d\n",sample_rate);
			//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Sample bit length %d\n",sample_bit_length);

		}
		else if(strncmp((char*)&hdr, "data", 4) == 0)
		{
			//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Found 'data' header\n");
			data_length = block_len;
			found_data = 1;
		}

		lseek(fd, current_offset + block_len + 8, SEEK_SET);
		current_offset += block_len;
	}
	close(fd);

	if(((format_data_length != 16) && (format_data_length != 18)) ||
	   (compression_code != 1) ||
	   (channel_count < 1))
	{
		DPRINTF(E_WARN, L_SCANNER, "Invalid wav header in %s\n", filename);
		return -1;
	}

	if( !data_length )
		data_length = psong->file_size - 44;

	bit_rate = sample_rate * channel_count * ((sample_bit_length + 7) / 8) * 8;
	psong->bitrate = bit_rate;
	psong->samplerate = sample_rate;
	psong->channels = channel_count;
	//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Data length: %d\n", data_length);
	sec = data_length / (bit_rate / 8);
	ms = ((data_length % (bit_rate / 8)) * 1000) / (bit_rate / 8);
	psong->song_length = (sec * 1000) + ms;
	//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Song length: %d\n", psong->song_length);
	//DEBUG DPRINTF(E_DEBUG,L_SCANNER,"Bit rate: %d\n", psong->bitrate);

	/* Upon further review, WAV files should be little-endian, and DLNA requires the LPCM profile to be big-endian.
	asprintf(&(psong->mime), "audio/L16;rate=%d;channels=%d", psong->samplerate, psong->channels);
	*/

	return 0;
}

static int
_get_wavfileinfo(char *filename, struct song_metadata *psong)
{
	psong->lossless = 1;
	/* Upon further review, WAV files should be little-endian, and DLNA requires the LPCM profile to be big-endian.
	asprintf(&(psong->dlna_pn), "LPCM");
	*/

	return 0;
}