ampache/lib/class/recommendation.class.php

<?php
/* vim:set tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab: */
/**
 * Recommendation Class
 *
 *
 * LICENSE: GNU General Public License, version 2 (GPLv2)
 * Copyright (c) 2001 - 2011 Ampache.org All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License v2
 * as published by the Free Software Foundation.
 *
 * 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.
 *
 * @package	Ampache
 * @copyright	2001 - 2011 Ampache.org
 * @license	http://opensource.org/licenses/gpl-2.0 GPLv2
 * @link	http://www.ampache.org/
 */

/**
 * Recommendation Class
 *
 * Description here...
 *
 * @package	Ampache
 * @copyright	2001 - 2011 Ampache.org
 * @license	http://opensource.org/licenses/gpl-2.0 GPLv2
 * @link	http://www.ampache.org/
 */
class Recommendation {

	/**
	 * Constructor
	 * Not on my watch, boyo.
	 */
	private function __construct() {
		return false;
	} //constructor

	/**
	 * get_lastfm_results
	 * Runs a last.fm query and returns the parsed results
	 */
	private static function get_lastfm_results($method, $query) {
		$api_key = Config::get('lastfm_api_key');
		$api_base = "http://ws.audioscrobbler.com/2.0/?method=";
		$url = $api_base . $method . '&api_key=' . $api_key . '&' . $query;
		debug_event('Recommendation', 'search url : ' . $url, 5);

		$snoopy = new Snoopy();
		if(Config::get('proxy_host') AND Config::get('proxy_port')) {
			$snoopy->proxy_user = Config::get('proxy_host');
			$snoopy->proxy_port = Config::get('proxy_port');
			$snoopy->proxy_user = Config::get('proxy_user');
			$snoopy->proxy_pass = Config::get('proxy_pass');
		}
		$snoopy->fetch($url);
		$content = $snoopy->results;
		
		return simplexml_load_string($content);
	} // get_lastfm_results

	/**
	 * get_songs_like
	 * Returns a list of similar songs
	 */
	public static function get_songs_like($song_id, $limit = 5, $local_only = true) {
		$song = new Song($song_id);

		if (isset($song->mbid)) {
			$query = 'mbid=' . rawurlencode($song->mbid);
		}
		else {
			$query = 'track=' . rawurlencode($song->title);
		}

		if ($limit && !$local_only) {
			$query .= "&limit=$limit";
		}
		
		$xml = self::get_lastfm_results('track.getsimilar', $query);

		foreach ($xml->similartracks->children() as $child) {
			$name = $child->name;
			$local_id = null;

			$artist_name = $child->artist->name;
			$s_artist_name = Catalog::trim_prefix($artist_name);
			$s_artist_name = Dba::escape($s_artist_name['string']);

			$sql = "SELECT `song`.`id` FROM `song` " .
				"LEFT JOIN `artist` ON " .
				"`song`.`artist`=`artist`.`id` WHERE " .
				"`song`.`title`='" . Dba::escape($name) . 
				"' AND `artist`.`name`='$s_artist_name'";

			$db_result = Dba::read($sql);
			
			if ($result = Dba::fetch_assoc($db_result)) {
				$local_id = $result['id'];
			}

			if (is_null($local_id)) {
				debug_event('Recommendation', "$name did not match any local song", 5);
				if (! $local_only) {
					$results[] = array(
						'id' => null,
						'title' => $name,
						'artist' => $artist_name
					);
				}
			}
			else {
				debug_event('Recommendation', "$name matched local song $local_id", 5);
				$results[] = array(
					'id' => $local_id,
					'title' => $name
				);
			}

			if ($limit && count($results) >= $limit) {
				break;
			}
		}

		if (isset($results)) {
			return $results;
		}

		return false;
	}

	/**
	 * get_artists_like
	 * Returns a list of similar artists
	 */
	public static function get_artists_like($artist_id, $limit = 5, $local_only = true) {
		$artist = new Artist($artist_id);

		$query = 'artist=' . rawurlencode($artist->name);
		if ($limit && !$local_only) {
			$query .= "&limit=$limit";
		}

		$xml = self::get_lastfm_results('artist.getsimilar', $query);	

		foreach ($xml->similarartists->children() as $child) {
			$name = $child->name;
			$local_id = null;

			// First we check by MBID
			if ((string)$child->mbid) {
				$mbid = Dba::escape($child->mbid);
				$sql = "SELECT `id` FROM `artist` WHERE `mbid`='$mbid'";
				$db_result = Dba::read($sql);
				if ($result = Dba::fetch_assoc($db_result)) {
					$local_id = $result['id'];
				}
			}

			// Then we fall back to the less likely to work exact
			// name match
			if (is_null($local_id)) {
				$searchname = Catalog::trim_prefix($name);
				$searchname = Dba::escape($searchname['string']);
				$sql = "SELECT `id` FROM `artist` WHERE `name`='$searchname'";
				$db_result = Dba::read($sql);
				if ($result = Dba::fetch_assoc($db_result)) {
					$local_id = $result['id'];
				}
			}
			
			// Then we give up
			if (is_null($local_id)) {
				debug_event('Recommendation', "$name did not match any local artist", 5);
				if (! $local_only) {
					$results[] = array(
						'id' => null,
						'name' => $name
					);
				}
			}
			else {
				debug_event('Recommendation', "$name matched local artist " . $local_id, 5);
				$results[] = array(
					'id' => $local_id,
					'name' => $name
				);
			}

			// Don't do more work than we have to
			if ($limit && count($results) >= $limit) {
				break;
			}
		}

		if (isset($results)) {
			return $results;
		}
		
		return false;
	} // get_artists_like

} // end of recommendation class
?>