ampache/lib/class/recommendation.class.php

<?php
/* vim:set tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab: */
/*

 Copyright (c) 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.

*/

/**
 * Recommendation Class
 */
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
?>