path: root/lib/class/browse.class.php

<?php
/*

 Copyright (c) 2001 - 2007 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.

*/

/**
 * Browse Class
 * This handles all of the sql/filtering
 * on the data before it's thrown out to the templates
 * it also handles pulling back the object_ids and then
 * calling the correct template for the object we are displaying
 */
class Browse { 

	// Public static vars that are cached
	public static $sql; 
	public static $start = '0'; 
	public static $total_objects; 

	/**
	 * constructor
	 * This should never be called
	 */
	private function __construct() { 

		// Rien a faire

	} // __construct


	/**
	 * set_filter
	 * This saves the filter data we pass it into the session
	 * This is done here so that it's easy to modify where the data
	 * is saved should I change my mind in the future. It also makes
	 * a single point for whitelist tweaks etc
	 */
	public static function set_filter($key,$value) { 

		switch ($key) { 
                        case 'show_art':
                        case 'min_count':
                        case 'unplayed':
                        case 'rated':
                                $key = $_REQUEST['key'];
				if ($_SESSION['browse']['filter'][$key]) { 
					unset($_SESSION['browse']['filter'][$key]);
				} 
				else { 
	                                $_SESSION['browse']['filter'][$key] = 1;
				}
                        break;
			case 'alpha_match':
				if ($value == _('All')) { $value = ''; } 
				$_SESSION['browse']['filter'][$key] = $value; 
			break;
                        default:
                                // Rien a faire
                        break;
                } // end switch
	
	} // set_filter

	/**
	 * get_filter
	 * returns the specified filter value
	 */
	public static function get_filter($key) { 
	
		// Simple enough, but if we ever move this crap 
		return $_SESSION['browse']['filter'][$key]; 

	} // get_filter


	/**
 	 * set_type
	 * This sets the type of object that we want to browse by
	 * we do this here so we only have to maintain a single whitelist
	 * and if I want to change the location I only have to do it here
	 */
	public static function set_type($type) { 

		switch($type) { 
			case 'user':
			case 'playlist':
			case 'song':
			case 'catalog':
			case 'album':
			case 'artist':
			case 'genre':
			case 'live_stream':
				$_SESSION['browse']['type'] = $type;
			break;
			default:
				// Rien a faire
			break;
		} // end type whitelist

	} // set_type

	/**
	 * set_sort
	 * This sets the current sort(s)
	 */
	public static function set_sort($sort) { 

		switch ($_SESSION['browse']['type']) { 
			case 'song': 
				$valid_array = array('title','year'); 
			break;
			case 'artist': 
				$valid_array = array('name'); 
			break;
			case 'album': 
				$valid_array = array('name','year'); 
			break;
		} // end switch  

		// If it's not in our list, smeg off!
		if (!in_array($sort,$valid_array)) { 
			return false; 
		} 
			
		if ($_SESSION['browse']['sort'][$sort] == 'DESC') { 
				$_SESSION['browse']['sort'][$sort] = 'ASC'; 
		}
		else { 
			$_SESSION['browse']['sort'][$sort] = 'DESC'; 
		} 

	} // set_sort

	/**
	 * set_start
	 * This sets the start point for our show functions
	 */
	public static function set_start($start) { 

		self::$start = intval($start); 

	} // set_start

	/**
	 * get_saved
	 * This looks in the session for the saved 
	 * stuff and returns what it finds
	 */
	public static function get_saved() { 

		$objects = $_SESSION['browse']['save']; 
		
		return $objects; 

	} // get_saved

	/**
	 * get_objects
	 * This gets an array of the ids of the objects that we are
	 * currently browsing by it applies the sql and logic based
	 * filters
	 */
	public static function get_objects() { 

		// First we need to get the SQL statement we are going to run
		// This has to run against any possible filters (dependent on type)
		$sql = self::get_sql(); 
		
		$db_results = Dba::query($sql); 

		$results = array(); 

		while ($data = Dba::fetch_assoc($db_results)) { 
			// Make sure that this object passes the logic filter
			if (self::logic_filter($data['id'])) { 
				$results[] = $data['id']; 
			} 
		} // end while
	
		// Save what we've found and then return it
		self::save_objects($results); 

		return $results; 

	} // get_objects

	/**
	 * get_sql
	 * This returns the sql statement we are going to use this has to be run
	 * every time we get the objects because it depends on the filters and the
	 * type of object we are currently browsing
	 */
	public static function get_sql() { 

		// Get our base SQL must always return ID 
		switch ($_SESSION['browse']['type']) { 
			case 'album':
				$sql = "SELECT `album`.`id` FROM `album` "; 
			break;
			case 'artist':
				$sql = "SELECT `artist`.`id` FROM `artist` "; 
			break;
			case 'genre':
				$sql = "SELECT `genre`.`id` FROM `genre` ";
			break;
			case 'user': 
				$sql = "SELECT `user`.`id` FROM `user` ";
			break;
			case 'live_stream':
				$sql = "SELECT `live_stream`.`id` FROM `live_stream` "; 
			break;
			case 'playlist': 
				$sql = "SELECT `playlist`.`id` FROM `playlist` "; 
			break;
			case 'song':
			default:
				$sql = "SELECT `song`.`id` FROM `song` ";  
			break;
		} // end base sql

		// No sense to go further if we don't have filters
		if (is_array($_SESSION['browse']['filter'])) { 

			// Foreach the filters and see if any of them can be applied
			// as part of a where statement in this sql (type dependent)
			$where_sql = "WHERE 1=1 AND ";
			
			foreach ($_SESSION['browse']['filter'] as $key=>$value) { 
				$where_sql .= self::sql_filter($key,$value); 	
			} // end foreach

			$where_sql = rtrim($where_sql,'AND ');

			$sql .= $where_sql;
		} // if filters

		// Now Add the Order 
		$order_sql = "ORDER BY "; 	

		// If we don't have a sort, then go ahead and return it now
		if (!is_array($_SESSION['browse']['sort'])) { return $sql; }

		foreach ($_SESSION['browse']['sort'] as $key=>$value) { 			
			$order_sql .= self::sql_sort($key,$value); 
		} 
		// Clean her up
		$order_sql = rtrim($order_sql,"ORDER BY "); 
		$order_sql = rtrim($order_sql,","); 

		$sql = $sql . $order_sql; 
		
		return $sql;

	} // get_sql 

	/**
	 * sql_filter
	 * This takes a filter name and value and if it is possible
	 * to filter by this name on this type returns the approiate sql
	 * if not returns nothing
	 */
	private static function sql_filter($filter,$value) { 

		$filter_sql = ''; 

		if ($_SESSION['browse']['type'] == 'song') { 
			switch($filter) { 
				case 'alpha_match':
					$filter_sql = " `song`.`title` LIKE '" . Dba::escape($value) . "%' AND ";
				break;
				case 'unplayed':
					$filter_sql = " `song`.`played`='0' AND "; 
				break;
				default: 
					// Rien a faire
				break;
			} // end list of sqlable filters
		} // if it is a song
		elseif ($_SESSION['browse']['type'] == 'album') { 
			switch($filter) { 
				case 'alpha_match':
					$filter_sql = " `album`.`name` LIKE '" . Dba::escape($value) . "%' AND "; 
				break;
				case 'min_count': 

				break;
				default: 
					// Rien a faire
				break;
			} 
		} // end album 
		elseif ($_SESSION['browse']['type'] == 'artist') { 
			switch($filter) { 
				case 'alpha_match':
					$filter_sql = " `artist`.`name` LIKE '" . Dba::escape($value) . "%' AND ";
				break;
				default:
					// Rien a faire
				break;
			} // end filter
		} // end artist
		elseif ($_SESSION['browse']['type'] == 'genre') { 
			switch ($filter) { 
				case 'alpha_match': 
					$filter_sql = " `genre`.`name` LIKE '" . Dba::escape($value) . "%' AND "; 
				break;
				default: 
					// Rien a faire
				break;
			} // end filter 
		} // end if genre
		elseif ($_SESSION['browse']['type'] == 'live_stream') { 
			switch ($filter) { 
				case 'alpha_match':
					$filter_sql = " `live_stream`.`name` LIKE '" . Dba::escape($value) . "%' AND "; 
				break;
				default: 
					// Rien a faire
				break;
			} // end filter
		} // end live_stream
		elseif ($_SESSION['browse']['type'] == 'playlist') { 
			switch ($filter) { 
				case 'alpha_match': 
					$filter_sql = " `playlist`.`name` LIKE '" . Dba::escape($value) . "%' AND "; 
				break;
				default; 
					// Rien a faire
				break;
			} // end filter
		} // end playlist
	
		return $filter_sql; 

	} // sql_filter

	/**
	 * logic_filter
	 * This runs the filters that we can't easily apply
	 * to the sql so they have to be done after the fact
	 * these should be limited as they are often intensive and
	 * require additional queries per object... :(
	 */
	private static function logic_filter($object_id) { 

		return true; 

	} // logic_filter

	/**
	 * sql_sort
	 * This builds any order bys we need to do
	 * to sort the results as best we can, there is also
	 * a logic based sort that will come later as that's
	 * a lot more complicated
	 */
	private static function sql_sort($field,$order) { 

		if ($order != 'DESC') { $order == 'ASC'; } 

		switch ($_SESSION['browse']['type']) { 
			case 'song': 
				switch($field) { 
					case 'title';
						$sql = "`song`.`title`"; 
					break;
					case 'year':
						$sql = "`song`.`year`"; 
					break;
						default: 
						// Rien a faire
					break;
				} // end switch
			break;
			case 'album': 
				switch($field) { 
					case 'name': 
						$sql = "`album`.`name`"; 
					break;
					case 'year': 
						$sql = "`album`.`year`"; 
					break;
				} // end switch
			break;
			case 'artist': 
				switch ($field) { 
					case 'name': 
						$sql = "`artist`.`name`"; 
					break;
				} // end switch 
			break;
			default: 
				// Rien a faire
			break;
		} // end switch

		if ($sql) { $sql_sort = "$sql $order,"; } 
		
		return $sql_sort; 

	} // sql_sort

	/**
	 * show_objects
	 * This takes an array of objects
	 * and requires the correct template based on the
	 * type that we are currently browsing
	 */
	public static function show_objects($object_ids='') { 

		$object_ids = $object_ids ? $object_ids : self::get_saved();

		// Reset the total items
		self::$total_objects = count($object_ids); 

		// Limit is based on the users preferences
		$limit = $GLOBALS['user']->prefs['offset_limit'] ? $GLOBALS['user']->prefs['offset_limit'] : '25'; 

		if (count($object_ids) > $start) { 
			$object_ids = array_slice($object_ids,self::$start,$limit); 
		} 

		// Format any matches we have so we can show them to the masses
		$match = $_SESSION['browse']['filter']['alpha_match'] ? ' (' . $_SESSION['browse']['filter']['alpha_match'] . ')' : '';  

		switch ($_SESSION['browse']['type']) { 
			case 'song': 
				show_box_top(_('Songs') . $match); 
				require_once Config::get('prefix') . '/templates/show_songs.inc.php'; 
				show_box_bottom(); 
			break;
			case 'album': 
				show_box_top(_('Albums') . $match); 
				require_once Config::get('prefix') . '/templates/show_albums.inc.php';
				show_box_bottom(); 
			break;
			case 'genre':
				show_box_top(_('Genres') . $match); 
				require_once Config::get('prefix') . '/templates/show_genres.inc.php'; 
				show_box_bottom(); 
			break;
			case 'user':
				show_box_top(_('Manage Users') . $match); 
				require_once Config::get('prefix') . '/templates/show_users.inc.php'; 
				show_box_bottom(); 
			break;
			case 'artist':
				show_box_top(_('Artists') . $match); 
				require_once Config::get('prefix') . '/templates/show_artists.inc.php'; 
				show_box_bottom(); 
			break;
			case 'live_stream': 
				show_box_top(_('Radion Stations') . $match); 
				require_once Config::get('prefix') . '/templates/show_live_streams.inc.php';
				show_box_bottom(); 
			break;
			case 'playlist': 
				show_box_top(_('Playlists') . $match);
				require_once Config::get('prefix') . '/templates/show_playlists.inc.php'; 
				show_box_bottom(); 
			break;
			case 'catalog': 
				show_box_top(_('Catalogs')); 
				require_once Config::get('prefix') . '/templates/show_catalogs.inc.php';
				show_box_bottom(); 
			break;
			default: 
				// Rien a faire
			break;
		} // end switch on type

	} // show_object

	/**
	 * save_objects
	 * This takes the full array of object ides, often passed into show and then
	 * if nessecary it saves them into the session
	 */
	public static function save_objects($object_ids) { 

		// save these objects
		$_SESSION['browse']['save'] = $object_ids; 
		self::$total_objects = count($object_ids); 
		return true; 

	} // save_objects

} // browse