/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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
 *
 *    https://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.grails.datastore.mapping.engine.event;

import org.springframework.context.ApplicationEvent;

import org.grails.datastore.mapping.core.Datastore;

/**
 * @author Burt Beckwith
 */
public abstract class AbstractPersistenceEventListener implements PersistenceEventListener {

    protected Datastore datastore;

    protected AbstractPersistenceEventListener(final Datastore datastore) {
        this.datastore = datastore;
    }

    /**
     * {@inheritDoc}
     * @see org.springframework.context.ApplicationListener#onApplicationEvent(
     *     org.springframework.context.ApplicationEvent)
     */
    public final void onApplicationEvent(ApplicationEvent e) {
        if (e instanceof AbstractPersistenceEvent) {

            AbstractPersistenceEvent event = (AbstractPersistenceEvent) e;
            if (!isValidSource(event)) {
                return;
            }

            if (event.isCancelled()) {
                return;
            }

            if (event.isListenerExcluded(getClass().getName())) {
                return;
            }
            onPersistenceEvent(event);
        }

    }

    protected boolean isValidSource(AbstractPersistenceEvent event) {
        Object source = event.getSource();
        return (source instanceof Datastore) && source.equals(datastore);
    }

    protected abstract void onPersistenceEvent(AbstractPersistenceEvent event);

    public int getOrder() {
        return DEFAULT_ORDER;
    }

    public boolean supportsSourceType(final Class<?> sourceType) {
        // ensure that this listener only handles its events (e.g. if Mongo and Redis are both installed)
        return datastore.getClass().isAssignableFrom(sourceType);
    }
}
