/*
 * Copyright 2005-2011 the original author or authors.
 * 
 * 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 org.wamblee.xmlrouter.impl;

import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;

import org.wamblee.xmlrouter.common.Id;
import org.wamblee.xmlrouter.config.Config;

/**
 * Default implementation of the {@link Config} interface.
 * 
 * @author Erik Brakkee
 * 
 * @param <T>
 */
public abstract class ConfigImpl<T> implements ExtendedConfig<T> {

    private boolean dirty;
    private AtomicLong next;
    private Map<Id<T>, T> registered;

    /**
     * Constructs the object.
     */
    public ConfigImpl(AtomicLong aNext) {
        dirty = false;
        next = aNext;
        registered = new LinkedHashMap<Id<T>, T>();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.wamblee.xmlrouter.config.Config#add(T)
     */
    @Override
    public synchronized Id<T> add(T aT) {
        notNull(aT);
        long seqno = next.incrementAndGet();
        Id<T> id = new Id<T>(seqno);
        registered.put(id, wrap(id, aT));
        dirty = true;
        return id;
    }

    /**
     * This is called to wrap the given object by a safer version.
     * 
     * @param aId
     *            Id.
     * @param aT
     *            Object to wrap.
     * @return Wrapped object.
     */
    public abstract T wrap(Id<T> aId, T aT);

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.wamblee.xmlrouter.config.Config#remove(org.wamblee.xmlrouter.common
     * .Id)
     */
    @Override
    public synchronized boolean remove(Id<T> aId) {
        notNull(aId);
        dirty = true;
        return registered.remove(aId) != null;
    }

    @Override
    public Map<Id<T>, T> map() {
        return Collections.unmodifiableMap(registered);
    }

    private void notNull(T aT) {
        if (aT == null) {
            throw new NullPointerException("Object is null");
        }
    }

    private void notNull(Id<T> aId) {
        if (aId == null) {
            throw new NullPointerException("Id is null");
        }
    }

    @Override
    public boolean isDirty() {
        return dirty;
    }

    @Override
    public void resetDirty() {
        dirty = false;
    }
}