<?PHP

/*
	torrent.php
	Classes and functions to hold data about torrent files, which can be used to query trackers or to simply display information on
	the torrent itself.
	This is a component of a BitTorrent tracker/torrent library.
	This library is free to redistribute, but I'd appreciate if you left the credit in if you use it.
	Written by Greg Poole | hide@address.com | http://m4dm4n.homelinux.net:8086
*/

require_once "bencode.reader.php";

class Torrent {

	var
		$announce,
		$announceList,
		$createdBy,
		$creationDate,
		$encoding,
		$name,
		$length,
		$files,
		$pieceLength,
		$pieces,
		$comment,
		$private,
		$md5sum,
		$filename,
		$infoHash,
		$totalSize,
		$modifiedBy,
		$error = false;

	function Torrent($filename) {	
		// Keep this info for reference later
		$this->filename = $filename;
		
		// The entire contents of a torrent file should form into a dictionary object, which will be used to get all our info.
		$reader = new BEncodeReader($filename);
		$torrentInfo = $reader->readNext();
		
		// In the case of an invalid torrent file the result of the readNext call will be "false".
		if($torrentInfo === false) {
			$this->error = true;
			trigger_error("The torrent file is invalid", E_USER_WARNING);
		}
		
		// Based on the information we've read in, we can now set up the contents of this class
		$this->announce = $torrentInfo['announce'];
		$this->announceList = $torrentInfo['announce-list'];
		$this->createdBy = $torrentInfo['created by'];
		$this->creationDate = $torrentInfo['creation date'];
		$this->comment = $torrentInfo['comment'];
		$this->modifiedBy = $torrentInfo['modified-by'];
		$this->pieceLength = $torrentInfo['info']['piece length'];
		$this->pieces = $torrentInfo['info']['pieces'];
		$this->private = ($torrentInfo['info']['private'] == 1);
		$this->name = $torrentInfo['info']['name'];
		$this->encoding = $torrentInfo['encoding'];
		$this->infoHash = $torrentInfo['info']['hash'];
		
		// Files gets a bit tricky. If it isn't defined then this is a single file torrent, which has only the info
		// about one file. Otherwise we have a list of files and path info for each.
		if(!isset($torrentInfo['info']['files'])) {
			$this->length = $torrentInfo['info']['length'];
			$this->md5sum = $torrentInfo['info']['md5sum'];
			$this->totalSize = $this->length;
		} else {
			$this->files = array();
			$this->totalSize = 0;
			foreach($torrentInfo['info']['files'] as $key=>$fileInfo) {
				$torrentFile = new TorrentFile();
				$torrentFile->md5sum = $fileInfo['md5sum'];
				$torrentFile->length = $fileInfo['length'];
				$torrentFile->name = implode("/",$fileInfo['path']);
				$this->files[$key] = $torrentFile;
				$this->totalSize += $torrentFile->length;
			}
		}
	}
}

// Class representing a file within a torrent
class TorrentFile {

	var $md5sum,$name,$length;

}

?>