/*
 * Copyright 2015 Daniel Dittmar
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package dan.dit.whatsthat.achievement;

import android.text.TextUtils;

import java.util.LinkedList;
import java.util.Queue;

import dan.dit.whatsthat.util.compaction.Compactable;
import dan.dit.whatsthat.util.general.RobustObserverController;

/**
 * This class encapsulates data that is set and updated by the client and notifies
 * listeners like Achievements that are interested in the data changing to update their state.
 * The AchievementData can be compacted and restored. It is uniquely identified by a data name
 * and holds a list of listeners.
 * Created by daniel on 12.05.15.
 */
public abstract class AchievementData implements Compactable {
    protected final String mName;
    private Queue<AchievementDataEvent> mEventFactory = new LinkedList<>();
    private RobustObserverController<AchievementDataEventListener, AchievementDataEvent>
            mObserverController;

    AchievementData(String dataName) {
        mName = dataName;
        mObserverController = new RobustObserverController<>();
        if (TextUtils.isEmpty(mName)) {
            throw new IllegalArgumentException("Null name given for achievement data.");
        }
    }

    protected AchievementDataEvent obtainNewEvent() {
        if (mEventFactory == null || mEventFactory.isEmpty()) {
            return new AchievementDataEvent();
        } else {
            return mEventFactory.poll();
        }
    }

    @Override
    public int hashCode() {
        return mName.hashCode();
    }

    @Override
    public boolean equals(Object other) {
        if (other instanceof AchievementData) {
            return mName.equals(((AchievementData) other).mName);
        } else {
            return super.equals(other);
        }
    }

    /**
     * Resets the data. Does not touch the listeners.
     */
    protected abstract void resetData();


    public boolean removeListener(AchievementDataEventListener listener) {
        return mObserverController.removeObserver(listener);
    }

    public void addListener(AchievementDataEventListener listener) {
        mObserverController.addObserver(listener);
    }

    public void notifyListeners(AchievementDataEvent event) {
        mObserverController.notifyObservers(event);
        mEventFactory.add(event); // free event
    }

}