/***
    *     Ambient - A music player for the Android platform
    Copyright (C) 2007 Martin Vysny
    
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    
   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, see <http://www.gnu.org/licenses/>.
   */
  
  package sk.baka.ambient.activity.search;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.EnumMap;
  import java.util.List;
  import java.util.StringTokenizer;
  
  import sk.baka.ambient.AmbientApplication;
  import sk.baka.ambient.activity.main.StaticPlaylistController;
  import sk.baka.ambient.collection.CategoryEnum;
  import sk.baka.ambient.collection.CollectionUtils;
  import sk.baka.ambient.collection.TrackMetadataBean;
  import sk.baka.ambient.library.Library;
  import sk.baka.ambient.library.LibraryUtils;
  import android.database.Cursor;
  
  /***
   * Search the collection for given query.
   * 
   * @author Martin Vysny
   */
  public final class LibraryEngine implements ISearchEngine {
  
  	private StaticPlaylistController controller = null;
  	private SearchActivity owner = null;
  	private int listViewId;
  
  	public boolean canSearchOffline() {
  		return true;
  	}
  
  	public void init(final SearchActivity owner, final int listViewId) {
  		this.owner = owner;
  		this.listViewId = listViewId;
  	}
  
  	public void passivate() {
  		controller = null;
  	}
  
  	public List<? extends Object> performSearch(String query) throws Exception {
  		// search as substring in the following categories: artist, album, track
  		// name. Use the OR operator for all words present in the query.
  		final StringTokenizer words = new StringTokenizer(query, " \r\t\f\n");
  		if (!words.hasMoreTokens()) {
  			// no words to search for? return empty list
  			return Collections.emptyList();
  		}
  		final List<String> searchFor = new ArrayList<String>();
  		for (; words.hasMoreTokens();) {
  			searchFor.add(words.nextToken());
  		}
  		// construct the criteria map
  		final EnumMap<CategoryEnum, List<String>> criteria = new EnumMap<CategoryEnum, List<String>>(
  				CategoryEnum.class);
  		criteria.put(CategoryEnum.Album, searchFor);
  		criteria.put(CategoryEnum.Artist, searchFor);
  		criteria.put(CategoryEnum.Title, searchFor);
  		// retrieve the track list
  		final Library lib = AmbientApplication.getInstance().getLibrary();
  		final Cursor c = lib.getBackend().findByCriteria(criteria, true, false,
  				null);
  		final List<TrackMetadataBean> tracks = LibraryUtils.pollTracks(c);
  		CollectionUtils.sortByAlbumOrder(tracks);
  		return tracks;
  	}
  
  	@SuppressWarnings("unchecked")
  	public void update(List<? extends Object> model) {
  		if (controller == null) {
  			controller = new StaticPlaylistController(listViewId, listViewId,
  					owner, (List<TrackMetadataBean>) model, false);
  		} else {
  			controller.setTracks((List<TrackMetadataBean>) model);
  		}
  	}
  
  	public SearchType getType() {
  		return SearchType.Library;
  	}
 
 	public boolean canPerformSearch() {
 		return true;
 	}
 }