/* 
 * Copyright 2008-2013, ETH Zürich, Samuel Welten, Michael Kuhn, Tobias Langner,
 * Sandro Affentranger, Lukas Bossard, Michael Grob, Rahul Jain, 
 * Dominic Langenegger, Sonia Mayor Alonso, Roger Odermatt, Tobias Schlueter,
 * Yannick Stucki, Sebastian Wendland, Samuel Zehnder, Samuel Zihlmann,       
 * Samuel Zweifel
 *
 * This file is part of Jukefox.
 *
 * Jukefox 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 any later version. Jukefox 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
 * Jukefox. If not, see <http://www.gnu.org/licenses/>.
 */
package ch.ethz.dcg.jukefox.playmode;

import ch.ethz.dcg.jukefox.commons.utils.Log;
import ch.ethz.dcg.jukefox.commons.utils.RandomProvider;
import ch.ethz.dcg.jukefox.model.AbstractCollectionModelManager;
import ch.ethz.dcg.jukefox.model.AbstractPlayerModelManager;
import ch.ethz.dcg.jukefox.model.collection.BaseAlbum;
import ch.ethz.dcg.jukefox.model.collection.BaseArtist;
import ch.ethz.dcg.jukefox.model.collection.IReadOnlyPlaylist;
import ch.ethz.dcg.jukefox.model.collection.PlaylistSong;
import ch.ethz.dcg.jukefox.model.commons.NoNextSongException;
import ch.ethz.dcg.jukefox.model.commons.PlaylistPositionOutOfRangeException;
import ch.ethz.dcg.jukefox.model.player.PlayModeType;
import ch.ethz.dcg.jukefox.model.player.PlayerAction;

/**
 * Repeats the playlist by going to the first song once the last one finished. If you're at the first song and try to go
 * back, you'll end up at the last song.
 */
public class ShufflePlaylistPlayMode extends BasePlayMode {

	private static final String TAG = ShufflePlaylistPlayMode.class.getSimpleName();

	protected int songAvoidanceNumber;

	public ShufflePlaylistPlayMode(AbstractCollectionModelManager collectionModel,
			AbstractPlayerModelManager playerModel, int songAvoidanceNumber) {
		super(collectionModel, playerModel);
		this.songAvoidanceNumber = songAvoidanceNumber;
	}

	private int getNextRandomSongPos(IReadOnlyPlaylist playlist) throws NoNextSongException,
			PlaylistPositionOutOfRangeException {
		PlaylistSong<BaseArtist, BaseAlbum> currentSong = null;
		try {
			currentSong = playlist.getSongAtPosition(playlist.getPositionInList());
		} catch (PlaylistPositionOutOfRangeException e) {
			Log.w(TAG, e);
		}
		int randomPos = RandomProvider.getRandom().nextInt(playlist.getSize());
		PlaylistSong<BaseArtist, BaseAlbum> tempSong = playlist.getSongAtPosition(randomPos);

		int avoidance = Math.min(songAvoidanceNumber, playlist.getSize() - 2);
		if (avoidance < 0) {
			avoidance = 0;
		}

		while (playerModel.getPlayLog().isSongInRecentHistory(tempSong, avoidance)
				|| isEqualToCurrentSong(currentSong, tempSong)) {
			randomPos = RandomProvider.getRandom().nextInt(playlist.getSize());
			tempSong = playlist.getSongAtPosition(randomPos);
		}
		return randomPos;
	}

	private boolean isEqualToCurrentSong(PlaylistSong<BaseArtist, BaseAlbum> currentSong,
			PlaylistSong<BaseArtist, BaseAlbum> tempSong) {
		if (currentSong == null || tempSong == null) {
			return false;
		}
		return currentSong.getId() == tempSong.getId();
	}

	@Override
	public PlayerControllerCommands next(IReadOnlyPlaylist currentPlaylist) throws NoNextSongException {
		PlayerControllerCommands commands = new PlayerControllerCommands();
		if (currentPlaylist.isPlaylistEmpty()) {
			return commands;
		}
		try {
			commands.setListPos(getNextRandomSongPos(currentPlaylist));
			commands.playerAction(PlayerAction.PLAY);
		} catch (PlaylistPositionOutOfRangeException e) {
			Log.w(TAG, e);
		}
		return commands;
	}

	@Override
	public PlayModeType getPlayModeType() {
		return PlayModeType.SHUFFLE_PLAYLIST;
	}

}