package org.musicontroller.gui.edit;
   
   import java.util.Date;
   import java.util.List;
   
   import org.apache.tapestry.IExternalPage;
   import org.apache.tapestry.IRequestCycle;
   import org.apache.tapestry.annotations.InjectObject;
   import org.apache.tapestry.engine.ExternalServiceParameter;
  import org.apache.tapestry.engine.IEngineService;
  import org.apache.tapestry.engine.ILink;
  import org.apache.tapestry.event.PageBeginRenderListener;
  import org.apache.tapestry.event.PageEndRenderListener;
  import org.apache.tapestry.event.PageEvent;
  import org.apache.tapestry.html.BasePage;
  import org.musicontroller.core.Playlist;
  import org.musicontroller.dao.BagAndKeywordUtils;
  import org.musicontroller.security.User;
  import org.musicontroller.service.McService;
  
  /**
   * <p>Implements the MusiController screen Edit Playlist. The functions of this screen:
   * <ul>
   *   <li> Change the name of the playlist.
   *   <li> Change the release date of the playlist.
   *   <li> Change the names of the songs on the playlist.
   *   <li> Change the lengths of the songs on the playlist.
   *   <li> Change the keywords of the songs on the playlist.
   *   <li> Add or Remove keywords to all songs at once.
   *   <li> Add or Remove an artist as a performer to some or all of the songs.
   *   <li> Change the cover art image of the playlist.
   * </ul>
   * <p>In additon, this screen provides:
   * <ul>
   *   <li> A link to the playlist info screen of the playlist.
   *   <li> A button to request all songs in the playlist.
   *   <li> A button to download a ZIP file with all songs in the playlist.
   *   <li> A picture of the cover art.
   * </ul>
   * 
   * @author Hans Drexler
   * @version $Id: PlaylistEdit.java,v 1.1 2010/03/16 18:55:42 varienaja Exp $
   */
  public abstract class PlaylistEdit extends BasePage implements PageBeginRenderListener, PageEndRenderListener, IExternalPage {
  
  	public abstract long getPlaylistId();
  	public abstract void setPlaylistId(long id);
  	public abstract void setPlaylistName(String playlistname);
  	public abstract void setPlaylistKeywords(String keywords);
  	public abstract void setPlaylistReleasedate(Date releasedate);
  	public abstract void setSongBeanList(List<SongBean> list);
  	
  	public abstract String getPlaylistName();
  	public abstract String getPlaylistKeywords();
  	public abstract Date getPlaylistReleasedate();
  	public abstract List<SongBean> getSongBeanList();
  	
  	public abstract List<AiRelationBean> getAiRelationList();
  	public abstract void setAiRelationList(List<AiRelationBean> relations);
  
  	public abstract String getArtistfirstname();
  	public abstract String getArtistlastname();
  	public abstract String getInstruments();
  	public abstract String getTracks();
  	public abstract void setArtistfirstname(String firstname);
  	public abstract void setArtistlastname(String lastname);
  	public abstract void setInstruments(String instruments);
  	public abstract void setTracks(String tracks);
  	
  	public abstract List<PlaylistMergeBean> getMergePlaylistBeanList();
  	public abstract void setMergePlaylistBeanList(List<PlaylistMergeBean> list);
  		
  	public abstract McService getMcService();
  
  	@InjectObject("engine-service:external")
  	public abstract IEngineService getExternalService();
  
  	public abstract User getUser();
  	
  	private Playlist _playlist;
  	
  	/**
  	 * The first parameter is always the playlist id. The second argument is optional.
  	 * When supplied, it contains a <code>CoverArtSearchResult</code> that has been
  	 * selected as the new cover art for this playlist. This argument can be ignored by
  	 * this page.
  	 */
  	public void activateExternalPage(Object[] args, IRequestCycle cycle) {
  		Long playlistid = (Long) args[0];
  		setPlaylistId(playlistid);
  	}
  
  	/**
  	 * Prepare the page for rendering. 
  	 * <ul>
  	 * <li>Fills the page properties for the playlist name, band name, release date
  	 * and keywords. 
  	 * <li>Builds a list of SongBean objects filled with the id, songname, bandname, 
  	 *     length and keyword list of each song. The list is saved as a page property. 
 	 *     The user will be able to see and modify the values stored in the SongBean objects.
 	 * <li>Builds a list of AiRelationBean objects for the artist-instrument relations that
 	 *     are part of every song in the playlist.
 	 * <li>Builds a list of PlaylistMergeBean objects, one for each playlist that has exactly
 	 *     the same name as the playlist being edited. Each bean has a boolean property with 
 	 *     which the user can indicate if the playslist should be merged with the playlist
 	 *     being edited.   
 	 * <li>Clear input fields that should always be reset before rendering.
 	 * @param event The page event.
 	 */
 	public void pageBeginRender(PageEvent event) {
 		Playlist playlist = getPlaylist();
 		setPlaylistName(playlist.getName());
 		setPlaylistReleasedate(playlist.getReleasedate());
 		setPlaylistKeywords("");
 		
 		setSongBeanList(getMcService().constructSongBeanList(playlist));
 
 		// Create a list of song beans from the playlist and initialize the songBeanList.
 		// Build the list of all artist-instrument relations of all songs in the playlist and
 		// construct a list of AiRelationBean objects from that list.
 		List<AiRelationBean> beanlist = BagAndKeywordUtils.buildAiRelationBeanList(playlist);
 		setAiRelationList(beanlist);
 		
 		// Determine a list of playlists having the same name as this playlist. Remove the playlist
 		// being edited from that list. Then, build a list of PlaylistMergeBeans for remaining playlists.
 		setMergePlaylistBeanList(getMcService().constructMergeBeanList(playlist));
 
 		// Clear input fields that should always be empty.
 		setArtistfirstname("");
 		setArtistlastname("");
 		setInstruments("");
 		setTracks("");
 	}
 
 	/**
 	 * Clear the page variables just before the page returns to the page pool.
 	 * @param event The page event.
 	 */
 	public void pageEndRender(PageEvent event) {
 		_playlist = null;
 	}
 	
 	/**
 	 * Lazily loads the playlist using the playlist id.
 	 * @return The playlist to edit.
 	 */
 	public Playlist getPlaylist() {
 		long id = getPlaylistId();
 		if(_playlist==null) {
 			_playlist = getMcService().getPlaylistById(id);
 		}
 		return _playlist;
 	}
 	
 	/**
 	 * Save the changed playlist properties releaseDate, playlist name. Merges
 	 * the playlists with another playlist of the same name if the user authorized it.
 	 * @param cycle The Tapestry MVC cycle.
 	 */
 	public void save(IRequestCycle cycle) {
 		getMcService().setPlaylistProperties(getPlaylist(),getPlaylistName(),getPlaylistReleasedate());
 		getMcService().mergePlaylist(getPlaylist(), getUser(), getMergePlaylistBeanList());
 	}
 		
 	/**
 	 * Add the keywords entered by the user to all songs in the playlist.
 	 * @param cycle The Tapestry MVC cycle.
 	 */
 	public void addKeywords(IRequestCycle cycle) {
 		getMcService().addKeywordsToPlaylist(getPlaylist(), getPlaylistKeywords(),null);	}
 
 	/**
 	 * Remove the keywords entered by the user from all songs in the playlist.
 	 * @param cycle The Tapestry MVC cycle.
 	 */
 	public void removeKeywords(IRequestCycle cycle) {
 		getMcService().removeKeywordsFromPlaylist(getPlaylist(), getPlaylistKeywords(),null);
 	}
 
 	/**
 	 * Cycle through the songs in the list of song beans and apply
 	 * changes to the song name, song length and song keywords to each.
 	 * 
 	 * @param cycle The Tapestry MVC cycle.
 	 */
 	public void editSongs(IRequestCycle cycle) {
 		List<SongBean> songbeans = getSongBeanList();
 		getMcService().editSongsOfPlaylist(getPlaylist(),songbeans);
 	}
 		
 	public void addMusician(IRequestCycle cycle) {
 		getMcService().addMusician(getPlaylist(), getArtistfirstname(), getArtistlastname(), getInstruments(), getTracks());
 	}
 
 	public void deleteMusician(IRequestCycle cycle) {
 		getMcService().deleteMusician(getPlaylist(), getArtistfirstname(), getArtistlastname(), getInstruments(), getTracks());
 	}
 			
 	/**
 	 * Goto the EditCoverArt page. Pass the page 2 parameters. The first is the playlist id of the playlist being
 	 * edited. The second is the name of the page the CoverArtEdit page should return to ("PlaylistEdit").
 	 */
 	public ILink editCoverArt(IRequestCycle cycle) {
 		IEngineService service = getExternalService();
 		ExternalServiceParameter parameter = new ExternalServiceParameter("CoverArtEdit", new Object[]{getPlaylist().getId(),"PlaylistEdit"});
 		ILink link = service.getLink(false, parameter);
 		return link;
 	}
 }