/*
 * Audio Clip Player TCSS 305 - Autumn 2008 (Zimmerman)
 */

package tetris.audio;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.Line;
import javax.sound.sampled.LineEvent;
import javax.sound.sampled.LineListener;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;

/**
 * A class to play audio clips. Caches previously-played clips, allowing fast
 * re-playback of previously played sounds.
 * 
 * @author Marty Stepp
 * @author Daniel M. Zimmerman (code cleanup)
 * @version 1.0
 */

public class SoundPlayer {
  /**
   * A cache of previously-played audio clips.
   */

  private final Map<String, Clip> my_clips = new HashMap<String, Clip>();

  /**
   * Plays the audio file with the given file name. This method returns
   * instantly, without waiting for the clip to finish playing.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to play.
   * @return a Clip object representing the sound played. (for convenience; this
   *         result need not be used/stored).
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip play(final String the_filename) throws IllegalArgumentException {
    final Clip clip = getClip(the_filename);

    if (clip != null) {
      clip.start();
    }

    return clip;
  }

  /**
   * Plays the audio file with the given file name, waiting until the clip is
   * done playing before returning.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to play.
   * @return a Clip object representing the sound played. (for convenience; this
   *         result need not be used/stored).
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip playAndWait(final String the_filename) throws IllegalArgumentException {
    final Clip clip = getClip(the_filename);

    if (clip != null) {
      clip.start();
      try {
        synchronized (clip) {
          while (clip.isRunning()) {
            clip.wait(); // wait for clip to finish
          }
        }
      } catch (final InterruptedException ie) {
        // ignored
        return clip;
      }
    }

    return clip;
  }

  /**
   * Plays the clip with the given file name in a continuous loop. The clip
   * keeps looping until it is later stopped by calling the stop() method. This
   * function returns instantly
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to play.
   * @return a Clip object representing the sound played. (for convenience; this
   *         result need not be used/stored).
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip loop(final String the_filename) throws IllegalArgumentException {
    return loop(the_filename, Clip.LOOP_CONTINUOUSLY);
  }

  /**
   * Plays the clip with the given file name in a loop. The clip loops until it
   * has played the specified number of times, or until it is later stopped by
   * calling the stop() method. This function returns instantly, without waiting
   * for the clip to finish looping.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to play.
   * @param the_number_of_times The number of times to loop the clip.
   * @return a Clip object representing the sound played. (for convenience; this
   *         result need not be used/stored).
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip loop(final String the_filename, final int the_number_of_times)
    throws IllegalArgumentException {
    final Clip clip = getClip(the_filename);

    if (clip != null) {
      clip.loop(the_number_of_times);
    }

    return clip;
  }

  /**
   * Plays the clip with the given file name in a loop. The clip loops
   * continuously until it is stopped by calling the stop() method. This method
   * waits until the clip is done looping before returning. Note that since the
   * clip loops continuously, this method will not return unless some other
   * thread stops the clip.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to play.
   * @return a Clip object representing the sound played. (for convenience; this
   *         result need not be used/stored).
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip loopAndWait(final String the_filename) throws IllegalArgumentException {
    return loopAndWait(the_filename, Clip.LOOP_CONTINUOUSLY);
  }

  /**
   * Plays the clip with the given file name in a loop. The clip loops until it
   * has played the specified number of times, or until it is stopped by calling
   * the stop() method. This method waits until the clip is done looping before
   * returning.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to play.
   * @param the_number_of_times The number of times to loop the clip.
   * @return a Clip object representing the sound played. (for convenience; this
   *         result need not be used/stored).
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip loopAndWait(final String the_filename, final int the_number_of_times)
    throws IllegalArgumentException {
    final Clip clip = getClip(the_filename);

    if (clip != null) {
      clip.loop(the_number_of_times);
      try {
        while (clip.isRunning()) {
          clip.wait(); // wait for clip to finish
        }
      } catch (final InterruptedException ie) {
        return clip;
      }
    }

    return clip;
  }

  /**
   * Pauses the clip with the given file name. If the clip is later played, it
   * will resume from where it was paused. Calling this method does not resume a
   * thread that is suspended on a playAndWait() or a loopAndWait().
   * 
   * If stop() is called on a paused clip, it will reset to the beginning of the
   * clip for the next play.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to pause.
   * @exception IllegalArgumentException if there is a problem reading from or
   *              playing the sound file.
   */

  public void pause(final String the_filename) throws IllegalArgumentException {
    final Clip clip = getClip(the_filename);

    if (clip != null) {
      final int pos = clip.getFramePosition();
      clip.stop();
      clip.setFramePosition(pos);
    }
  }

  /**
   * Stops the clip with the specified filename (and wakes up any threads
   * waiting for it to finish playing).
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to stop.
   * @return a Clip object representing the sound stopped.
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip stop(final String the_filename) throws IllegalArgumentException {
    final Clip clip = getClip(the_filename);
    stopClip(clip);

    return clip;
  }

  /**
   * Stops all currently playing sound clips (and wakes up the threads waiting
   * for them to finish playing).
   */

  public void stopAll() {
    for (Clip clip : my_clips.values()) {
      stopClip(clip);
    }
  }

  /**
   * Preloads the clip at the given file name. This means the clip will be
   * available faster, when requested for playing the first time.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to preload.
   * @return a Clip object representing the preloaded sound.
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  public Clip preLoad(final String the_filename) throws IllegalArgumentException {
    return getClip(the_filename);
  }

  /**
   * Returns a Clip object for a filename, either by creating a new one or
   * loading it from the cache.
   * 
   * @param the_filename The name of the file (relative to the current working
   *          directory) to load.
   * @return a Clip object, or null if one is not found.
   * @exception IllegalArgumentException if there is a problem reading from the
   *              sound file.
   */

  private Clip getClip(final String the_filename) throws IllegalArgumentException {
    Clip clip = null;
    AudioInputStream ais = null;

    if (my_clips.containsKey(the_filename)) {
      clip = my_clips.get(the_filename);
    } else {
      // read audio file from disk
      try {
        ais = AudioSystem.getAudioInputStream(ClassLoader.getSystemResource(the_filename));
        clip = (Clip) AudioSystem.getLine(new Line.Info(Clip.class));
        clip.open(ais);
        clip.addLineListener(new LineListener() {
          /**
           * Responds to audio events generated by clips.
           * 
           * @param the_event The event generated.
           */

          public void update(final LineEvent the_event) {
            if (the_event.getType() == LineEvent.Type.STOP) {
              // clip is done playing
              stopClip((Clip) the_event.getSource());
            }
          }
        });
        my_clips.put(the_filename, clip);
      } catch (final UnsupportedAudioFileException uafe) {
        throw new IllegalArgumentException("Not a valid supported audio file: \"" +
                                           the_filename + "\"");
      } catch (final LineUnavailableException lue) {
        throw new IllegalArgumentException("Line is not available to play sound \"" +
                                           the_filename + "\"");
      } catch (final IOException ioe) {
        throw new IllegalArgumentException("I/O error while reading file: \"" + the_filename +
                                           "\"");
      }
    }

    return clip;
  }

  /**
   * Stops the playing of the specified clip.
   * 
   * @param the_clip The clip.
   */

  private void stopClip(final Clip the_clip) {
    if (the_clip != null) {
      synchronized (the_clip) {
        the_clip.stop();
        the_clip.setFramePosition(0);
        the_clip.notifyAll(); // awaken threads waiting for this Clip
      }
    }
  }
}

// end of class SoundPlayer