<?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.apetag.php                                       //

// module for analyzing APE tags                               //

// dependencies: NONE                                          //

//                                                            ///

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

class getid3_apetag extends getid3_handler

{

	public $inline_attachments = true; // true: return full data for all attachments; false: return no data for all attachments; integer: return data for attachments <= than this; string: save as file to this directory

	public $overrideendoffset  = 0;

	public function Analyze() {

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

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

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

			return false;

		}

		$id3v1tagsize     = 128;

		$apetagheadersize = 32;

		$lyrics3tagsize   = 10;

		if ($this->overrideendoffset == 0) {

			fseek($this->getid3->fp, 0 - $id3v1tagsize - $apetagheadersize - $lyrics3tagsize, SEEK_END);

			$APEfooterID3v1 = fread($this->getid3->fp, $id3v1tagsize + $apetagheadersize + $lyrics3tagsize);

			//if (preg_match('/APETAGEX.{24}TAG.{125}$/i', $APEfooterID3v1)) {

			if (substr($APEfooterID3v1, strlen($APEfooterID3v1) - $id3v1tagsize - $apetagheadersize, 8) == 'APETAGEX') {

				// APE tag found before ID3v1

				$info['ape']['tag_offset_end'] = $info['filesize'] - $id3v1tagsize;

			//} elseif (preg_match('/APETAGEX.{24}$/i', $APEfooterID3v1)) {

			} elseif (substr($APEfooterID3v1, strlen($APEfooterID3v1) - $apetagheadersize, 8) == 'APETAGEX') {

				// APE tag found, no ID3v1

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

			}

		} else {

			fseek($this->getid3->fp, $this->overrideendoffset - $apetagheadersize, SEEK_SET);

			if (fread($this->getid3->fp, 8) == 'APETAGEX') {

				$info['ape']['tag_offset_end'] = $this->overrideendoffset;

			}

		}

		if (!isset($info['ape']['tag_offset_end'])) {

			// APE tag not found

			unset($info['ape']);

			return false;

		}

		// shortcut

		$thisfile_ape = &$info['ape'];

		fseek($this->getid3->fp, $thisfile_ape['tag_offset_end'] - $apetagheadersize, SEEK_SET);

		$APEfooterData = fread($this->getid3->fp, 32);

		if (!($thisfile_ape['footer'] = $this->parseAPEheaderFooter($APEfooterData))) {

			$info['error'][] = 'Error parsing APE footer at offset '.$thisfile_ape['tag_offset_end'];

			return false;

		}

		if (isset($thisfile_ape['footer']['flags']['header']) && $thisfile_ape['footer']['flags']['header']) {

			fseek($this->getid3->fp, $thisfile_ape['tag_offset_end'] - $thisfile_ape['footer']['raw']['tagsize'] - $apetagheadersize, SEEK_SET);

			$thisfile_ape['tag_offset_start'] = ftell($this->getid3->fp);

			$APEtagData = fread($this->getid3->fp, $thisfile_ape['footer']['raw']['tagsize'] + $apetagheadersize);

		} else {

			$thisfile_ape['tag_offset_start'] = $thisfile_ape['tag_offset_end'] - $thisfile_ape['footer']['raw']['tagsize'];

			fseek($this->getid3->fp, $thisfile_ape['tag_offset_start'], SEEK_SET);

			$APEtagData = fread($this->getid3->fp, $thisfile_ape['footer']['raw']['tagsize']);

		}

		$info['avdataend'] = $thisfile_ape['tag_offset_start'];

		if (isset($info['id3v1']['tag_offset_start']) && ($info['id3v1']['tag_offset_start'] < $thisfile_ape['tag_offset_end'])) {

			$info['warning'][] = 'ID3v1 tag information ignored since it appears to be a false synch in APEtag data';

			unset($info['id3v1']);

			foreach ($info['warning'] as $key => $value) {

				if ($value == 'Some ID3v1 fields do not use NULL characters for padding') {

					unset($info['warning'][$key]);

					sort($info['warning']);

					break;

				}

			}

		}

		$offset = 0;

		if (isset($thisfile_ape['footer']['flags']['header']) && $thisfile_ape['footer']['flags']['header']) {

			if ($thisfile_ape['header'] = $this->parseAPEheaderFooter(substr($APEtagData, 0, $apetagheadersize))) {

				$offset += $apetagheadersize;

			} else {

				$info['error'][] = 'Error parsing APE header at offset '.$thisfile_ape['tag_offset_start'];

				return false;

			}

		}

		// shortcut

		$info['replay_gain'] = array();

		$thisfile_replaygain = &$info['replay_gain'];

		for ($i = 0; $i < $thisfile_ape['footer']['raw']['tag_items']; $i++) {

			$value_size = getid3_lib::LittleEndian2Int(substr($APEtagData, $offset, 4));

			$offset += 4;

			$item_flags = getid3_lib::LittleEndian2Int(substr($APEtagData, $offset, 4));

			$offset += 4;

			if (strstr(substr($APEtagData, $offset), "\x00") === false) {

				$info['error'][] = 'Cannot find null-byte (0x00) seperator between ItemKey #'.$i.' and value. ItemKey starts '.$offset.' bytes into the APE tag, at file offset '.($thisfile_ape['tag_offset_start'] + $offset);

				return false;

			}

			$ItemKeyLength = strpos($APEtagData, "\x00", $offset) - $offset;

			$item_key      = strtolower(substr($APEtagData, $offset, $ItemKeyLength));

			// shortcut

			$thisfile_ape['items'][$item_key] = array();

			$thisfile_ape_items_current = &$thisfile_ape['items'][$item_key];

			$thisfile_ape_items_current['offset'] = $thisfile_ape['tag_offset_start'] + $offset;

			$offset += ($ItemKeyLength + 1); // skip 0x00 terminator

			$thisfile_ape_items_current['data'] = substr($APEtagData, $offset, $value_size);

			$offset += $value_size;

			$thisfile_ape_items_current['flags'] = $this->parseAPEtagFlags($item_flags);

			switch ($thisfile_ape_items_current['flags']['item_contents_raw']) {

				case 0: // UTF-8

				case 3: // Locator (URL, filename, etc), UTF-8 encoded

					$thisfile_ape_items_current['data'] = explode("\x00", trim($thisfile_ape_items_current['data']));

					break;

				default: // binary data

					break;

			}

			switch (strtolower($item_key)) {

				case 'replaygain_track_gain':

					$thisfile_replaygain['track']['adjustment'] = (float) str_replace(',', '.', $thisfile_ape_items_current['data'][0]); // float casting will see "0,95" as zero!

					$thisfile_replaygain['track']['originator'] = 'unspecified';

					break;

				case 'replaygain_track_peak':

					$thisfile_replaygain['track']['peak']       = (float) str_replace(',', '.', $thisfile_ape_items_current['data'][0]); // float casting will see "0,95" as zero!

					$thisfile_replaygain['track']['originator'] = 'unspecified';

					if ($thisfile_replaygain['track']['peak'] <= 0) {

						$info['warning'][] = 'ReplayGain Track peak from APEtag appears invalid: '.$thisfile_replaygain['track']['peak'].' (original value = "'.$thisfile_ape_items_current['data'][0].'")';

					}

					break;

				case 'replaygain_album_gain':

					$thisfile_replaygain['album']['adjustment'] = (float) str_replace(',', '.', $thisfile_ape_items_current['data'][0]); // float casting will see "0,95" as zero!

					$thisfile_replaygain['album']['originator'] = 'unspecified';

					break;

				case 'replaygain_album_peak':

					$thisfile_replaygain['album']['peak']       = (float) str_replace(',', '.', $thisfile_ape_items_current['data'][0]); // float casting will see "0,95" as zero!

					$thisfile_replaygain['album']['originator'] = 'unspecified';

					if ($thisfile_replaygain['album']['peak'] <= 0) {

						$info['warning'][] = 'ReplayGain Album peak from APEtag appears invalid: '.$thisfile_replaygain['album']['peak'].' (original value = "'.$thisfile_ape_items_current['data'][0].'")';

					}

					break;

				case 'mp3gain_undo':

					list($mp3gain_undo_left, $mp3gain_undo_right, $mp3gain_undo_wrap) = explode(',', $thisfile_ape_items_current['data'][0]);

					$thisfile_replaygain['mp3gain']['undo_left']  = intval($mp3gain_undo_left);

					$thisfile_replaygain['mp3gain']['undo_right'] = intval($mp3gain_undo_right);

					$thisfile_replaygain['mp3gain']['undo_wrap']  = (($mp3gain_undo_wrap == 'Y') ? true : false);

					break;

				case 'mp3gain_minmax':

					list($mp3gain_globalgain_min, $mp3gain_globalgain_max) = explode(',', $thisfile_ape_items_current['data'][0]);

					$thisfile_replaygain['mp3gain']['globalgain_track_min'] = intval($mp3gain_globalgain_min);

					$thisfile_replaygain['mp3gain']['globalgain_track_max'] = intval($mp3gain_globalgain_max);

					break;

				case 'mp3gain_album_minmax':

					list($mp3gain_globalgain_album_min, $mp3gain_globalgain_album_max) = explode(',', $thisfile_ape_items_current['data'][0]);

					$thisfile_replaygain['mp3gain']['globalgain_album_min'] = intval($mp3gain_globalgain_album_min);

					$thisfile_replaygain['mp3gain']['globalgain_album_max'] = intval($mp3gain_globalgain_album_max);

					break;

				case 'tracknumber':

					if (is_array($thisfile_ape_items_current['data'])) {

						foreach ($thisfile_ape_items_current['data'] as $comment) {

							$thisfile_ape['comments']['track'][] = $comment;

						}

					}

					break;

				case 'cover art (artist)':

				case 'cover art (back)':

				case 'cover art (band logo)':

				case 'cover art (band)':

				case 'cover art (colored fish)':

				case 'cover art (composer)':

				case 'cover art (conductor)':

				case 'cover art (front)':

				case 'cover art (icon)':

				case 'cover art (illustration)':

				case 'cover art (lead)':

				case 'cover art (leaflet)':

				case 'cover art (lyricist)':

				case 'cover art (media)':

				case 'cover art (movie scene)':

				case 'cover art (other icon)':

				case 'cover art (other)':

				case 'cover art (performance)':

				case 'cover art (publisher logo)':

				case 'cover art (recording)':

				case 'cover art (studio)':

					// list of possible cover arts from http://taglib-sharp.sourcearchive.com/documentation/2.0.3.0-2/Ape_2Tag_8cs-source.html

					list($thisfile_ape_items_current['filename'], $thisfile_ape_items_current['data']) = explode("\x00", $thisfile_ape_items_current['data'], 2);

					$thisfile_ape_items_current['data_offset'] = $thisfile_ape_items_current['offset'] + strlen($thisfile_ape_items_current['filename']."\x00");

					$thisfile_ape_items_current['data_length'] = strlen($thisfile_ape_items_current['data']);

					$thisfile_ape_items_current['image_mime'] = '';

					$imageinfo = array();

					$imagechunkcheck = getid3_lib::GetDataImageSize($thisfile_ape_items_current['data'], $imageinfo);

					$thisfile_ape_items_current['image_mime'] = image_type_to_mime_type($imagechunkcheck[2]);

					do {

						if ($this->inline_attachments === false) {

							// skip entirely

							unset($thisfile_ape_items_current['data']);

							break;

						}

						if ($this->inline_attachments === true) {

							// great

						} elseif (is_int($this->inline_attachments)) {

							if ($this->inline_attachments < $thisfile_ape_items_current['data_length']) {

								// too big, skip

								$info['warning'][] = 'attachment at '.$thisfile_ape_items_current['offset'].' is too large to process inline ('.number_format($thisfile_ape_items_current['data_length']).' bytes)';

								unset($thisfile_ape_items_current['data']);

								break;

							}

						} elseif (is_string($this->inline_attachments)) {

							$this->inline_attachments = rtrim(str_replace(array('/', '\\'), DIRECTORY_SEPARATOR, $this->inline_attachments), DIRECTORY_SEPARATOR);

							if (!is_dir($this->inline_attachments) || !is_writable($this->inline_attachments)) {

								// cannot write, skip

								$info['warning'][] = 'attachment at '.$thisfile_ape_items_current['offset'].' cannot be saved to "'.$this->inline_attachments.'" (not writable)';

								unset($thisfile_ape_items_current['data']);

								break;

							}

						}

						// if we get this far, must be OK

						if (is_string($this->inline_attachments)) {

							$destination_filename = $this->inline_attachments.DIRECTORY_SEPARATOR.md5($info['filenamepath']).'_'.$thisfile_ape_items_current['data_offset'];

							if (!file_exists($destination_filename) || is_writable($destination_filename)) {

								file_put_contents($destination_filename, $thisfile_ape_items_current['data']);

							} else {

								$info['warning'][] = 'attachment at '.$thisfile_ape_items_current['offset'].' cannot be saved to "'.$destination_filename.'" (not writable)';

							}

							$thisfile_ape_items_current['data_filename'] = $destination_filename;

							unset($thisfile_ape_items_current['data']);

						} else {

							if (!isset($info['ape']['comments']['picture'])) {

								$info['ape']['comments']['picture'] = array();

							}

							$info['ape']['comments']['picture'][] = array('data'=>$thisfile_ape_items_current['data'], 'image_mime'=>$thisfile_ape_items_current['image_mime']);

						}

					} while (false);

					break;

				default:

					if (is_array($thisfile_ape_items_current['data'])) {

						foreach ($thisfile_ape_items_current['data'] as $comment) {

							$thisfile_ape['comments'][strtolower($item_key)][] = $comment;

						}

					}

					break;

			}

		}

		if (empty($thisfile_replaygain)) {

			unset($info['replay_gain']);

		}

		return true;

	}

	public function parseAPEheaderFooter($APEheaderFooterData) {

		// http://www.uni-jena.de/~pfk/mpp/sv8/apeheader.html

		// shortcut

		$headerfooterinfo['raw'] = array();

		$headerfooterinfo_raw = &$headerfooterinfo['raw'];

		$headerfooterinfo_raw['footer_tag']   =                  substr($APEheaderFooterData,  0, 8);

		if ($headerfooterinfo_raw['footer_tag'] != 'APETAGEX') {

			return false;

		}

		$headerfooterinfo_raw['version']      = getid3_lib::LittleEndian2Int(substr($APEheaderFooterData,  8, 4));

		$headerfooterinfo_raw['tagsize']      = getid3_lib::LittleEndian2Int(substr($APEheaderFooterData, 12, 4));

		$headerfooterinfo_raw['tag_items']    = getid3_lib::LittleEndian2Int(substr($APEheaderFooterData, 16, 4));

		$headerfooterinfo_raw['global_flags'] = getid3_lib::LittleEndian2Int(substr($APEheaderFooterData, 20, 4));

		$headerfooterinfo_raw['reserved']     =                              substr($APEheaderFooterData, 24, 8);

		$headerfooterinfo['tag_version']         = $headerfooterinfo_raw['version'] / 1000;

		if ($headerfooterinfo['tag_version'] >= 2) {

			$headerfooterinfo['flags'] = $this->parseAPEtagFlags($headerfooterinfo_raw['global_flags']);

		}

		return $headerfooterinfo;

	}

	public function parseAPEtagFlags($rawflagint) {

		// "Note: APE Tags 1.0 do not use any of the APE Tag flags.

		// All are set to zero on creation and ignored on reading."

		// http://www.uni-jena.de/~pfk/mpp/sv8/apetagflags.html

		$flags['header']            = (bool) ($rawflagint & 0x80000000);

		$flags['footer']            = (bool) ($rawflagint & 0x40000000);

		$flags['this_is_header']    = (bool) ($rawflagint & 0x20000000);

		$flags['item_contents_raw'] =        ($rawflagint & 0x00000006) >> 1;

		$flags['read_only']         = (bool) ($rawflagint & 0x00000001);

		$flags['item_contents']     = $this->APEcontentTypeFlagLookup($flags['item_contents_raw']);

		return $flags;

	}

	public function APEcontentTypeFlagLookup($contenttypeid) {

		static $APEcontentTypeFlagLookup = array(

			0 => 'utf-8',

			1 => 'binary',

			2 => 'external',

			3 => 'reserved'

		);

		return (isset($APEcontentTypeFlagLookup[$contenttypeid]) ? $APEcontentTypeFlagLookup[$contenttypeid] : 'invalid');

	}

	public function APEtagItemIsUTF8Lookup($itemkey) {

		static $APEtagItemIsUTF8Lookup = array(

			'title',

			'subtitle',

			'artist',

			'album',

			'debut album',

			'publisher',

			'conductor',

			'track',

			'composer',

			'comment',

			'copyright',

			'publicationright',

			'file',

			'year',

			'record date',

			'record location',

			'genre',

			'media',

			'related',

			'isrc',

			'abstract',

			'language',

			'bibliography'

		);

		return in_array(strtolower($itemkey), $APEtagItemIsUTF8Lookup);

	}

}