/**

 * HTML via Java(tm) Language Bindings

 * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * 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, version 2 of the License.

 *

 * 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. apidesign.org

 * designates this particular file as subject to the

 * "Classpath" exception as provided by apidesign.org

 * in the License file that accompanied this code.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://wiki.apidesign.org/wiki/GPLwithClassPathException

 */

package net.java.html.sound;

import java.util.ServiceLoader;

import org.apidesign.html.sound.spi.AudioEnvironment;

/** Handle to an audio clip which can be {@link #play() played}, {@link #pause() paused}

 * and etc. Obtain new instance via {@link #create(java.lang.String) create} factory 

 * method and then use it when necessary.

 *

 * @author antonepple

 */

public abstract class AudioClip {

    private AudioClip() {

    }

    /** Creates new instance of an audio clip based on the provided URL.

     * 

     * @param src the URL where to find the audio clip

     * @return the audio clip handle

     * @throws NullPointerException if src is <code>null</code>

     */

    public static AudioClip create(String src) {

        src.getClass();

        for (AudioEnvironment<?> ae : ServiceLoader.load(AudioEnvironment.class)) {

            Impl handle = create(ae, src);

            if (handle != null) {

                return handle;

            }

        }

        throw new IllegalStateException();

    }

    /** Plays the clip from begining to the end.

     */

    public abstract void play();

    /** Pauses playback of the clip

     */

    public abstract void pause();

    /**

     * Specifies the volume of the audio. Must be a number between 0.0 and 1.0:

     * <ul>

     *   <li>1.0 - highest volume</li>

     *   <li>0.5 - 50% volume</li>

     *   <li>0.0 - silent</li>

     * </ul>

     * 

     * @param volume for the playback

     */

    public abstract void setVolume(double volume);

//    public abstract void playFrom(int seconds);

    //

    // Implementation

    //

    private static <Audio> Impl<Audio> create(AudioEnvironment<Audio> env, String src) {

        Audio a = env.create(src);

        if (a != null) {

            return new Impl<Audio>(env, src, a);

        } else {

            return null;

        }

    }

    private static final class Impl<Audio> extends AudioClip {

        private final String src;

        private final Audio clip;

        private final AudioEnvironment<Audio> env;

        public Impl(AudioEnvironment<Audio> env, String src, Audio clip) {

            this.clip = clip;

            this.env = env;

            this.src = src;

        }

        @Override

        public void play() {

            env.play(clip);

        }

        @Override

        public void pause() {

            env.pause(clip);

        }

        @Override

        public void setVolume(double volume) {

            env.setVolume(clip, volume);

        }

        @Override

        public int hashCode() {

            return 59 * src.hashCode();

        }

        @Override

        public boolean equals(Object obj) {

            if (obj instanceof Impl) {

                return src.equals(((Impl)obj).src);

            }

            return false;

        }

    } // end of Impl

}