<?php

/////////////////////////////////////////////////////////////////

/// getID3() by James Heinrich <info@getid3.org>               //

//  available at http://getid3.sourceforge.net                 //

//            or http://www.getid3.org                         //

/////////////////////////////////////////////////////////////////

// See readme.txt for more details                             //

/////////////////////////////////////////////////////////////////

//                                                             //

// module.tag.id3v1.php                                        //

// module for analyzing ID3v1 tags                             //

// dependencies: NONE                                          //

//                                                            ///

/////////////////////////////////////////////////////////////////

class getid3_id3v1 extends getid3_handler

{

	public function Analyze() {

		$info = &$this->getid3->info;

		if (!getid3_lib::intValueSupported($info['filesize'])) {

			$info['warning'][] = 'Unable to check for ID3v1 because file is larger than '.round(PHP_INT_MAX / 1073741824).'GB';

			return false;

		}

		fseek($this->getid3->fp, -256, SEEK_END);

		$preid3v1 = fread($this->getid3->fp, 128);

		$id3v1tag = fread($this->getid3->fp, 128);

		if (substr($id3v1tag, 0, 3) == 'TAG') {

			$info['avdataend'] = $info['filesize'] - 128;

			$ParsedID3v1['title']   = $this->cutfield(substr($id3v1tag,   3, 30));

			$ParsedID3v1['artist']  = $this->cutfield(substr($id3v1tag,  33, 30));

			$ParsedID3v1['album']   = $this->cutfield(substr($id3v1tag,  63, 30));

			$ParsedID3v1['year']    = $this->cutfield(substr($id3v1tag,  93,  4));

			$ParsedID3v1['comment'] =                 substr($id3v1tag,  97, 30);  // can't remove nulls yet, track detection depends on them

			$ParsedID3v1['genreid'] =             ord(substr($id3v1tag, 127,  1));

			// If second-last byte of comment field is null and last byte of comment field is non-null

			// then this is ID3v1.1 and the comment field is 28 bytes long and the 30th byte is the track number

			if (($id3v1tag{125} === "\x00") && ($id3v1tag{126} !== "\x00")) {

				$ParsedID3v1['track']   = ord(substr($ParsedID3v1['comment'], 29,  1));

				$ParsedID3v1['comment'] =     substr($ParsedID3v1['comment'],  0, 28);

			}

			$ParsedID3v1['comment'] = $this->cutfield($ParsedID3v1['comment']);

			$ParsedID3v1['genre'] = $this->LookupGenreName($ParsedID3v1['genreid']);

			if (!empty($ParsedID3v1['genre'])) {

				unset($ParsedID3v1['genreid']);

			}

			if (isset($ParsedID3v1['genre']) && (empty($ParsedID3v1['genre']) || ($ParsedID3v1['genre'] == 'Unknown'))) {

				unset($ParsedID3v1['genre']);

			}

			foreach ($ParsedID3v1 as $key => $value) {

				$ParsedID3v1['comments'][$key][0] = $value;

			}

			// ID3v1 data is supposed to be padded with NULL characters, but some taggers pad with spaces

			$GoodFormatID3v1tag = $this->GenerateID3v1Tag(

											$ParsedID3v1['title'],

											$ParsedID3v1['artist'],

											$ParsedID3v1['album'],

											$ParsedID3v1['year'],

											(isset($ParsedID3v1['genre']) ? $this->LookupGenreID($ParsedID3v1['genre']) : false),

											$ParsedID3v1['comment'],

											(!empty($ParsedID3v1['track']) ? $ParsedID3v1['track'] : ''));

			$ParsedID3v1['padding_valid'] = true;

			if ($id3v1tag !== $GoodFormatID3v1tag) {

				$ParsedID3v1['padding_valid'] = false;

				$info['warning'][] = 'Some ID3v1 fields do not use NULL characters for padding';

			}

			$ParsedID3v1['tag_offset_end']   = $info['filesize'];

			$ParsedID3v1['tag_offset_start'] = $ParsedID3v1['tag_offset_end'] - 128;

			$info['id3v1'] = $ParsedID3v1;

		}

		if (substr($preid3v1, 0, 3) == 'TAG') {

			// The way iTunes handles tags is, well, brain-damaged.

			// It completely ignores v1 if ID3v2 is present.

			// This goes as far as adding a new v1 tag *even if there already is one*

			// A suspected double-ID3v1 tag has been detected, but it could be that

			// the "TAG" identifier is a legitimate part of an APE or Lyrics3 tag

			if (substr($preid3v1, 96, 8) == 'APETAGEX') {

				// an APE tag footer was found before the last ID3v1, assume false "TAG" synch

			} elseif (substr($preid3v1, 119, 6) == 'LYRICS') {

				// a Lyrics3 tag footer was found before the last ID3v1, assume false "TAG" synch

			} else {

				// APE and Lyrics3 footers not found - assume double ID3v1

				$info['warning'][] = 'Duplicate ID3v1 tag detected - this has been known to happen with iTunes';

				$info['avdataend'] -= 128;

			}

		}

		return true;

	}

	public static function cutfield($str) {

		return trim(substr($str, 0, strcspn($str, "\x00")));

	}

	public static function ArrayOfGenres($allowSCMPXextended=false) {

		static $GenreLookup = array(

			0    => 'Blues',

			1    => 'Classic Rock',

			2    => 'Country',

			3    => 'Dance',

			4    => 'Disco',

			5    => 'Funk',

			6    => 'Grunge',

			7    => 'Hip-Hop',

			8    => 'Jazz',

			9    => 'Metal',

			10   => 'New Age',

			11   => 'Oldies',

			12   => 'Other',

			13   => 'Pop',

			14   => 'R&B',

			15   => 'Rap',

			16   => 'Reggae',

			17   => 'Rock',

			18   => 'Techno',

			19   => 'Industrial',

			20   => 'Alternative',

			21   => 'Ska',

			22   => 'Death Metal',

			23   => 'Pranks',

			24   => 'Soundtrack',

			25   => 'Euro-Techno',

			26   => 'Ambient',

			27   => 'Trip-Hop',

			28   => 'Vocal',

			29   => 'Jazz+Funk',

			30   => 'Fusion',

			31   => 'Trance',

			32   => 'Classical',

			33   => 'Instrumental',

			34   => 'Acid',

			35   => 'House',

			36   => 'Game',

			37   => 'Sound Clip',

			38   => 'Gospel',

			39   => 'Noise',

			40   => 'Alt. Rock',

			41   => 'Bass',

			42   => 'Soul',

			43   => 'Punk',

			44   => 'Space',

			45   => 'Meditative',

			46   => 'Instrumental Pop',

			47   => 'Instrumental Rock',

			48   => 'Ethnic',

			49   => 'Gothic',

			50   => 'Darkwave',

			51   => 'Techno-Industrial',

			52   => 'Electronic',

			53   => 'Pop-Folk',

			54   => 'Eurodance',

			55   => 'Dream',

			56   => 'Southern Rock',

			57   => 'Comedy',

			58   => 'Cult',

			59   => 'Gangsta Rap',

			60   => 'Top 40',

			61   => 'Christian Rap',

			62   => 'Pop/Funk',

			63   => 'Jungle',

			64   => 'Native American',

			65   => 'Cabaret',

			66   => 'New Wave',

			67   => 'Psychedelic',

			68   => 'Rave',

			69   => 'Showtunes',

			70   => 'Trailer',

			71   => 'Lo-Fi',

			72   => 'Tribal',

			73   => 'Acid Punk',

			74   => 'Acid Jazz',

			75   => 'Polka',

			76   => 'Retro',

			77   => 'Musical',

			78   => 'Rock & Roll',

			79   => 'Hard Rock',

			80   => 'Folk',

			81   => 'Folk/Rock',

			82   => 'National Folk',

			83   => 'Swing',

			84   => 'Fast-Fusion',

			85   => 'Bebob',

			86   => 'Latin',

			87   => 'Revival',

			88   => 'Celtic',

			89   => 'Bluegrass',

			90   => 'Avantgarde',

			91   => 'Gothic Rock',

			92   => 'Progressive Rock',

			93   => 'Psychedelic Rock',

			94   => 'Symphonic Rock',

			95   => 'Slow Rock',

			96   => 'Big Band',

			97   => 'Chorus',

			98   => 'Easy Listening',

			99   => 'Acoustic',

			100  => 'Humour',

			101  => 'Speech',

			102  => 'Chanson',

			103  => 'Opera',

			104  => 'Chamber Music',

			105  => 'Sonata',

			106  => 'Symphony',

			107  => 'Booty Bass',

			108  => 'Primus',

			109  => 'Porn Groove',

			110  => 'Satire',

			111  => 'Slow Jam',

			112  => 'Club',

			113  => 'Tango',

			114  => 'Samba',

			115  => 'Folklore',

			116  => 'Ballad',

			117  => 'Power Ballad',

			118  => 'Rhythmic Soul',

			119  => 'Freestyle',

			120  => 'Duet',

			121  => 'Punk Rock',

			122  => 'Drum Solo',

			123  => 'A Cappella',

			124  => 'Euro-House',

			125  => 'Dance Hall',

			126  => 'Goa',

			127  => 'Drum & Bass',

			128  => 'Club-House',

			129  => 'Hardcore',

			130  => 'Terror',

			131  => 'Indie',

			132  => 'BritPop',

			133  => 'Negerpunk',

			134  => 'Polsk Punk',

			135  => 'Beat',

			136  => 'Christian Gangsta Rap',

			137  => 'Heavy Metal',

			138  => 'Black Metal',

			139  => 'Crossover',

			140  => 'Contemporary Christian',

			141  => 'Christian Rock',

			142  => 'Merengue',

			143  => 'Salsa',

			144  => 'Thrash Metal',

			145  => 'Anime',

			146  => 'JPop',

			147  => 'Synthpop',

			255  => 'Unknown',

			'CR' => 'Cover',

			'RX' => 'Remix'

		);

		static $GenreLookupSCMPX = array();

		if ($allowSCMPXextended && empty($GenreLookupSCMPX)) {

			$GenreLookupSCMPX = $GenreLookup;

			// http://www.geocities.co.jp/SiliconValley-Oakland/3664/alittle.html#GenreExtended

			// Extended ID3v1 genres invented by SCMPX

			// Note that 255 "Japanese Anime" conflicts with standard "Unknown"

			$GenreLookupSCMPX[240] = 'Sacred';

			$GenreLookupSCMPX[241] = 'Northern Europe';

			$GenreLookupSCMPX[242] = 'Irish & Scottish';

			$GenreLookupSCMPX[243] = 'Scotland';

			$GenreLookupSCMPX[244] = 'Ethnic Europe';

			$GenreLookupSCMPX[245] = 'Enka';

			$GenreLookupSCMPX[246] = 'Children\'s Song';

			$GenreLookupSCMPX[247] = 'Japanese Sky';

			$GenreLookupSCMPX[248] = 'Japanese Heavy Rock';

			$GenreLookupSCMPX[249] = 'Japanese Doom Rock';

			$GenreLookupSCMPX[250] = 'Japanese J-POP';

			$GenreLookupSCMPX[251] = 'Japanese Seiyu';

			$GenreLookupSCMPX[252] = 'Japanese Ambient Techno';

			$GenreLookupSCMPX[253] = 'Japanese Moemoe';

			$GenreLookupSCMPX[254] = 'Japanese Tokusatsu';

			//$GenreLookupSCMPX[255] = 'Japanese Anime';

		}

		return ($allowSCMPXextended ? $GenreLookupSCMPX : $GenreLookup);

	}

	public static function LookupGenreName($genreid, $allowSCMPXextended=true) {

		switch ($genreid) {

			case 'RX':

			case 'CR':

				break;

			default:

				if (!is_numeric($genreid)) {

					return false;

				}

				$genreid = intval($genreid); // to handle 3 or '3' or '03'

				break;

		}

		$GenreLookup = self::ArrayOfGenres($allowSCMPXextended);

		return (isset($GenreLookup[$genreid]) ? $GenreLookup[$genreid] : false);

	}

	public static function LookupGenreID($genre, $allowSCMPXextended=false) {

		$GenreLookup = self::ArrayOfGenres($allowSCMPXextended);

		$LowerCaseNoSpaceSearchTerm = strtolower(str_replace(' ', '', $genre));

		foreach ($GenreLookup as $key => $value) {

			if (strtolower(str_replace(' ', '', $value)) == $LowerCaseNoSpaceSearchTerm) {

				return $key;

			}

		}

		return false;

	}

	public static function StandardiseID3v1GenreName($OriginalGenre) {

		if (($GenreID = self::LookupGenreID($OriginalGenre)) !== false) {

			return self::LookupGenreName($GenreID);

		}

		return $OriginalGenre;

	}

	public static function GenerateID3v1Tag($title, $artist, $album, $year, $genreid, $comment, $track='') {

		$ID3v1Tag  = 'TAG';

		$ID3v1Tag .= str_pad(trim(substr($title,  0, 30)), 30, "\x00", STR_PAD_RIGHT);

		$ID3v1Tag .= str_pad(trim(substr($artist, 0, 30)), 30, "\x00", STR_PAD_RIGHT);

		$ID3v1Tag .= str_pad(trim(substr($album,  0, 30)), 30, "\x00", STR_PAD_RIGHT);

		$ID3v1Tag .= str_pad(trim(substr($year,   0,  4)),  4, "\x00", STR_PAD_LEFT);

		if (!empty($track) && ($track > 0) && ($track <= 255)) {

			$ID3v1Tag .= str_pad(trim(substr($comment, 0, 28)), 28, "\x00", STR_PAD_RIGHT);

			$ID3v1Tag .= "\x00";

			if (gettype($track) == 'string') {

				$track = (int) $track;

			}

			$ID3v1Tag .= chr($track);

		} else {

			$ID3v1Tag .= str_pad(trim(substr($comment, 0, 30)), 30, "\x00", STR_PAD_RIGHT);

		}

		if (($genreid < 0) || ($genreid > 147)) {

			$genreid = 255; // 'unknown' genre

		}

		switch (gettype($genreid)) {

			case 'string':

			case 'integer':

				$ID3v1Tag .= chr(intval($genreid));

				break;

			default:

				$ID3v1Tag .= chr(255); // 'unknown' genre

				break;

		}

		return $ID3v1Tag;

	}

}