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/**
 * 	This file is part of Kayak.
 *
 *	Kayak is free software: you can redistribute it and/or modify
 *	it under the terms of the GNU Lesser General Public License as published by
 *	the Free Software Foundation, either version 3 of the License, or
 *	(at your option) any later version.
 *
 *	Kayak 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 Lesser General Public License
 *	along with Kayak.  If not, see .
 *
 */
package com.github.andy2003.core;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.logging.Logger;

/**
 * A Subscription describes the relation between a class that acts as a frame
 * source and a class that wants to receive frames. The receiver can subscribe
 * or unsubscribe IDs and the source can check if a frame should be delivered
 * to the receiver.
 * @author Jan-Niklas Meier 
 *
 */
public class Subscription {

    private static final Logger logger = Logger.getLogger(Subscription.class.getName());

    private final Set ids = Collections.synchronizedSet(new HashSet());
    private final Set extendedIds = Collections.synchronizedSet(new HashSet());
    private Boolean muted;
    private Boolean subscribeAll;
    private FrameListener receiver;
    private SubscriptionChangeListener changeReceiver;

    /**
     * Creates a new Subscription. The new Subscription is automatically
     * registered at the {@link SubscriptionChangeReceiver}.
     * @param receiver
     * @param changeReceiver
     */
    public Subscription(FrameListener receiver, SubscriptionChangeListener changeReceiver) {
        muted = false;
        subscribeAll = false;
        this.receiver = receiver;
        this.changeReceiver = changeReceiver;

        changeReceiver.addSubscription(this);
    }

    /**
     * Subscribe for a single identifier
     * @param id identifier
     */
    public void subscribe(int id, boolean extended) {
        if(!extended) {
            synchronized(ids) {
                if (!ids.contains(id)) {
                    ids.add(id);
                }
                changeReceiver.subscribed(id, false, this);
            }
        } else {
            synchronized(extendedIds) {
                if (!extendedIds.contains(id)) {
                    extendedIds.add(id);
                }
                changeReceiver.subscribed(id, true, this);
            }
        }
    }

    /**
     * Remove all identifiers from the subscription.
     */
    public void clear() {
        Integer[] identifiers = null;
        synchronized(ids) {
            identifiers = ids.toArray(new Integer[ids.size()]);
            ids.clear();
        }

        for (int i=0;i getAllIdentifiers(boolean extended) {
        if(extended)
            return Collections.unmodifiableSet(extendedIds);
        else
            return Collections.unmodifiableSet(ids);
    }

    /**
     * Informs the {@link SubscriptionChangeReceiver} that the Subscription
     * will not be used anymore and no more Frames shall be received.
     */
    public void Terminate() {
        if(changeReceiver != null)
            changeReceiver.subscriptionTerminated(this);
    }
}