//=============================================================================
//
//   File : MpMp3.cpp
//   Creation date : Fri Mar 25 20:01:25 2005 GMT by Szymon Stefanek
//
//   This file is part of the KVIrc irc client distribution
//   Copyright (C) 2005-2010 Szymon Stefanek (pragma at kvirc dot net)
//
//   This file is based on the mp3tech.c. It is released under the original
//   license and the original copyright notice follows.
//
//   mp3tech.c
//
//   Copyright (C) 2000  Cedric Tefft <cedric@earthling.net>
//
//   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
//   This file is based in part on:
//
//   * MP3Info 0.5 by Ricardo Cerqueira <rmc@rccn.net>
//   * MP3Stat 0.9 by Ed Sweetman <safemode@voicenet.com> and
//                    Johannes Overmann <overmann@iname.com>
//
//   There has been also a remarkable work by Cristopher Tieckle (Crissi)
//
//=============================================================================

#include "MpMp3.h"
#include "KviOptions.h"

#include <QFileInfo>
#include <QTextCodec>

#define MAXGENRE   147
#define GENREROWS  50

/*
   The Information is stored in the last 128 bytes of an MP3. The Tag
   has got the following fields, and the offsets given here, are from
   0-127.

     Field      Length    Offsets
     Tag        3           0-2
     Songname   30          3-32
     Artist     30         33-62
     Album      30         63-92
     Year       4          93-96
     Comment    30         97-126
     Genre      1           127


   The string-fields contain ASCII-data, coded in ISO-Latin 1 codepage.
   Strings which are smaller than the field length are padded with zero-
   bytes.

     Tag: The tag is valid if this field contains the string "TAG". This
        has to be uppercase!

     Songname: This field contains the title of the MP3 (string as
        above).

     Artist: This field contains the artist of the MP3 (string as above).

     Album: this field contains the album where the MP3 comes from
        (string as above).

     Year: this field contains the year when this song has originally
        been released (string as above).

     Comment: this field contains a comment for the MP3 (string as
        above). Revision to this field has been made in ID3v1.1. See
        A.4.

     Genre: this byte contains the offset of a genre in a predefined
        list the byte is treated as an unsigned byte. The offset is
        starting from 0. See A.3.
*/


const char *typegenre [MAXGENRE+2] =
{
	"Blues","Classic Rock","Country","Dance","Disco","Funk","Grunge",
	"Hip-Hop","Jazz","Metal","New Age","Oldies","Other","Pop","R&B",
	"Rap","Reggae","Rock","Techno","Industrial","Alternative","Ska",
	"Death Metal","Pranks","Soundtrack","Euro-Techno","Ambient",
	"Trip-Hop","Vocal","Jazz+Funk","Fusion","Trance","Classical",
	"Instrumental","Acid","House","Game","Sound Clip","Gospel","Noise",
	"Alt. Rock","Bass","Soul","Punk","Space","Meditative",
	"Instrumental Pop","Instrumental Rock","Ethnic","Gothic",
	"Darkwave","Techno-Industrial","Electronic","Pop-Folk","Eurodance",
	"Dream","Southern Rock","Comedy","Cult","Gangsta Rap","Top 40",
	"Christian Rap","Pop/Funk","Jungle","Native American","Cabaret",
	"New Wave","Psychedelic","Rave","Showtunes","Trailer","Lo-Fi",
	"Tribal","Acid Punk","Acid Jazz","Polka","Retro","Musical",
	"Rock & Roll","Hard Rock","Folk","Folk/Rock","National Folk",
	"Swing","Fast-Fusion","Bebob","Latin","Revival","Celtic",
	"Bluegrass","Avantgarde","Gothic Rock","Progressive Rock",
	"Psychedelic Rock","Symphonic Rock","Slow Rock","Big Band",
	"Chorus","Easy Listening","Acoustic","Humour","Speech","Chanson",
	"Opera","Chamber Music","Sonata","Symphony","Booty Bass","Primus",
	"Porn Groove","Satire","Slow Jam","Club","Tango","Samba",
	"Folklore","Ballad","Power Ballad","Rhythmic Soul","Freestyle",
	"Duet","Punk Rock","Drum Solo","A Cappella","Euro-House",
	"Dance Hall","Goa","Drum & Bass","Club-House","Hardcore","Terror",
	"Indie","BritPop","Negerpunk","Polsk Punk","Beat",
	"Christian Gangsta Rap","Heavy Metal","Black Metal","Crossover",
	"Contemporary Christian","Christian Rock","Merengue","Salsa",
	"Thrash Metal","Anime","JPop","Synthpop",""
};

const char * get_typegenre(int idx)
{
	if(idx > MAXGENRE)return typegenre[12];
	return typegenre[idx];
}

int galphagenreindex[MAXGENRE+2] =
{
	148,123,74,73,34,99,40,20,26,145,90,
	116,41,135,85,96,138,89,0,107,132,65,88,
	104,102,97,136,61,141,1,32,128,112,57,140,
	2,139,58,125,3,50,22,4,55,127,122,120,
	98,52,48,124,25,54,84,81,115,80,119,5,
	30,36,59,126,38,91,49,6,79,129,137,7,
	35,100,131,19,46,47,33,146,29,8,63,86,
	71,45,142,9,77,82,64,133,10,66,39,11,
	103,12,75,134,53,62,13,109,117,23,108,92,
	93,67,121,43,14,15,68,16,76,87,118,78,
	17,143,114,110,69,21,111,95,105,42,37,24,
	56,44,101,83,94,106,147,113,51,18,130,144,
	60,70,31,72,27,28
};

int *alphagenreindex=&(galphagenreindex[1]);


int layer_tab[4]= {0, 3, 2, 1};

int frequencies[3][4] =
{
	{22050,24000,16000,50000},  /* MPEG 2.0 */
	{44100,48000,32000,50000},  /* MPEG 1.0 */
	{11025,12000,8000,50000}    /* MPEG 2.5 */
};

int bitrate[2][3][14] =
{
	{ /* MPEG 2.0 */
		{32,48,56,64,80,96,112,128,144,160,176,192,224,256},  /* layer 1 */
		{8,16,24,32,40,48,56,64,80,96,112,128,144,160},       /* layer 2 */
		{8,16,24,32,40,48,56,64,80,96,112,128,144,160}        /* layer 3 */
	},
	{ /* MPEG 1.0 */
		{32,64,96,128,160,192,224,256,288,320,352,384,416,448}, /* layer 1 */
		{32,48,56,64,80,96,112,128,160,192,224,256,320,384},    /* layer 2 */
		{32,40,48,56,64,80,96,112,128,160,192,224,256,320}      /* layer 3 */
	}
};

int frame_size_index[] = {24000, 72000, 72000};

const char *mode_text[] =
{
	"Stereo", "Joint Stereo", "Dual Channel", "Mono"
};

const char *emphasis_text[] =
{
	"None", "50/15 Microseconds", "Reserved", "CCITT J 17"
};

void resetmp3infoStruct(mp3info *i)
{
	i->file=0;
	i->datasize=0;
	i->header_isvalid=0;
	memset(&i->header,0,sizeof(i->header));
	i->id3_isvalid=0;
	memset(&i->id3,0,sizeof(i->id3));
	i->vbr=0;
	i->vbr_average=0;
	i->seconds=0;
	i->frames=0;
	i->badframes=0;
}

int get_mp3_info(mp3info *mp3)
{
//	mp3header header;

	QFile fi(mp3->filename);
	mp3->datasize=fi.size();//filestat.st_size;

	get_id3(mp3);

	if(get_first_header(mp3,0L))
	{
		int bitrate,counter=0;
		int data_start=ftell(mp3->file);
		int lastrate=15-mp3->header.bitrate;
		while((counter < NUM_SAMPLES) && lastrate)
		{
			int sample_pos=(counter*(mp3->datasize/NUM_SAMPLES+1))+data_start;
			if(get_first_header(mp3,sample_pos))
			{
				bitrate=15-mp3->header.bitrate;
			} else {
				bitrate=-1;
			}

			if(bitrate != lastrate)
			{
				mp3->vbr=1;
			}
			lastrate=bitrate;
			counter++;

		}
		mp3->frames=(mp3->datasize-data_start)/(frame_length(&mp3->header));
		mp3->seconds = (int)((float)(frame_length(&mp3->header)*mp3->frames)/
				       (float)(header_bitrate(&mp3->header)*125)+0.5);
		mp3->vbr_average = (float)header_bitrate(&mp3->header);
	}

	return 0;
}

int get_first_header(mp3info *mp3, long startpos)
{
	int k, l=0,c;
	mp3header h, h2;
	long valid_start=0;

	fseek(mp3->file,startpos,SEEK_SET);
	while(1)
	{
		while((c=fgetc(mp3->file)) != 255 && (c != EOF)) {}
		if(c == 255)
		{
			ungetc(c,mp3->file);
			valid_start=ftell(mp3->file);
			if((l=get_header(mp3->file,&h)))
			{
				fseek(mp3->file,l-FRAME_HEADER_SIZE,SEEK_CUR);
				for(k=1; (k < MIN_CONSEC_GOOD_FRAMES) && (mp3->datasize-ftell(mp3->file) >= FRAME_HEADER_SIZE); k++)
				{
					if(!(l=get_header(mp3->file,&h2))) break;
					if(!sameConstant(&h,&h2)) break;
					fseek(mp3->file,l-FRAME_HEADER_SIZE,SEEK_CUR);
				}
				if(k == MIN_CONSEC_GOOD_FRAMES)
				{
					fseek(mp3->file,valid_start,SEEK_SET);
					memcpy(&(mp3->header), &h2, sizeof(mp3header));
					mp3->header_isvalid = 1;
					return 1;
				}
			}
		} else {
			return 0;
		}
	}
	return 0;
}


// Get next MP3 frame header.
//   Return codes:
//   positive value = Frame Length of this header
//   0 = No, we did not retrieve a valid frame header

int get_header(FILE *file,mp3header *header)
{
	unsigned char buffer[FRAME_HEADER_SIZE];
	int fl;

	if(fread(&buffer,FRAME_HEADER_SIZE,1,file)<1)
	{
		header->sync=0;
		return 0;
	}
	header->sync=(((int)buffer[0]<<4) | ((int)(buffer[1]&0xE0)>>4));
	if(buffer[1] & 0x10) header->version=(buffer[1] >> 3) & 1;
	else header->version=2;
	header->layer=(buffer[1] >> 1) & 3;
	if((header->sync != 0xFFE) || (header->layer != 1))
	{
		header->sync=0;
		return 0;
	}
	header->crc=buffer[1] & 1;
	header->bitrate=(buffer[2] >> 4) & 0x0F;
	header->freq=(buffer[2] >> 2) & 0x3;
	header->padding=(buffer[2] >>1) & 0x1;
	header->extension=(buffer[2]) & 0x1;
	header->mode=(buffer[3] >> 6) & 0x3;
	header->mode_extension=(buffer[3] >> 4) & 0x3;
	header->copyright=(buffer[3] >> 3) & 0x1;
	header->original=(buffer[3] >> 2) & 0x1;
	header->emphasis=(buffer[3]) & 0x3;

	return ((fl=frame_length(header)) >= MIN_FRAME_SIZE ? fl : 0);
}

int frame_length(mp3header *header)
{
	return header->sync == 0xFFE ?
		(frame_size_index[3-header->layer]*((header->version&1)+1)*
		    header_bitrate(header)/header_frequency(header))+
		    header->padding : 1;
}

int header_layer(mp3header *h)
{
	return layer_tab[h->layer];
}

int header_bitrate(mp3header *h)
{
	if(h->bitrate > 0)
		return bitrate[h->version & 1][3-h->layer][h->bitrate-1];
	else
		return -1; // unknown
}

int header_frequency(mp3header *h)
{
	return frequencies[h->version][h->freq];
}

const char *header_emphasis(mp3header *h)
{
	return emphasis_text[h->emphasis];
}

const char *header_mode(mp3header *h)
{
	return mode_text[h->mode];
}

int header_channels(mp3header * h)
{
	return h->mode == 3 ? 1 : 2;
}

int header_crc(mp3header *h)
{
	return (!h->crc);
}

int sameConstant(mp3header *h1, mp3header *h2)
{
	if((*(uint*)h1) == (*(uint*)h2)) return 1;

	if((h1->version       == h2->version         ) &&
	(h1->layer         == h2->layer           ) &&
	(h1->crc           == h2->crc             ) &&
	(h1->freq          == h2->freq            ) &&
	(h1->mode          == h2->mode            ) &&
	(h1->copyright     == h2->copyright       ) &&
	(h1->original      == h2->original        ) &&
	(h1->emphasis      == h2->emphasis        ))
		return 1;
	else return 0;
}

int get_id3(mp3info *mp3)
{
	// this will read ID3v1 tags
	int retcode=0;
	char fbuf[4];

	if(mp3->datasize >= 128)
	{
		if(fseek(mp3->file, -128, SEEK_END ))
		{
			retcode |= 4;
		} else {
			size_t dummy = fread(fbuf,1,3,mp3->file); fbuf[3] = '\0';
			Q_UNUSED(dummy);
			mp3->id3.genre[0]=255;

			if(!strcmp((const char *)"TAG",(const char *)fbuf))
			{
				mp3->id3_isvalid=1;
				mp3->datasize -= 128;
				fseek(mp3->file, -125, SEEK_END);
				dummy = fread(mp3->id3.title,1,30,mp3->file); mp3->id3.title[30] = '\0';
				dummy = fread(mp3->id3.artist,1,30,mp3->file); mp3->id3.artist[30] = '\0';
				dummy = fread(mp3->id3.album,1,30,mp3->file); mp3->id3.album[30] = '\0';
				dummy = fread(mp3->id3.year,1,4,mp3->file); mp3->id3.year[4] = '\0';
				dummy = fread(mp3->id3.comment,1,30,mp3->file); mp3->id3.comment[30] = '\0';
				if(mp3->id3.comment[28] == '\0')
				{
					mp3->id3.track[0] = mp3->id3.comment[29];
				}
				dummy = fread(mp3->id3.genre,1,1,mp3->file);
				unpad(mp3->id3.title);
				unpad(mp3->id3.artist);
				unpad(mp3->id3.album);
				unpad(mp3->id3.year);
				unpad(mp3->id3.comment);
			}
		}
	}
	return retcode;
}

char *pad(char *string, int length)
{
	int l;

	l=strlen(string);
	while(l<length)
	{
		string[l] = ' ';
		l++;
	}

	string[l]='\0';
	return string;
}

// Remove trailing whitespace from the end of a string
char *unpad(char *string)
{
	char *pos=string+strlen(string)-1;
	while(isspace(pos[0])) (pos--)[0]=0;
	return string;
}

bool scan_mp3_file(QString&,mp3info * i)
{
	//memset(i,0,sizeof(mp3info));
	resetmp3infoStruct(i);


	i->filename = "text";
	i->file = fopen(QTextCodec::codecForLocale()->fromUnicode(i->filename).data(),"rb");
	if(!i->file)return false;

	get_mp3_info(i);

	fclose(i->file);

	return (i->id3_isvalid);
}
