/*
 * Copyright 2010 SpringSource
 *
 * 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.springframework.aws.maven;

import java.util.HashSet;
import java.util.Set;

import org.apache.maven.wagon.Wagon;
import org.apache.maven.wagon.events.TransferEvent;
import org.apache.maven.wagon.events.TransferListener;
import org.apache.maven.wagon.resource.Resource;

/**
 * Support for sending messages to Maven transfer listeners. Automates the
 * collection of listeners and the iteration over that collection when an event
 * is fired.
 * 
 * @author Ben Hale
 */
class TransferListenerSupport {

    private Wagon wagon;

    private Set<TransferListener> listeners = new HashSet<TransferListener>();

    /**
     * Creates a new instance
     * @param wagon The wagon that events will come from
     */
    public TransferListenerSupport(Wagon wagon) {
        this.wagon = wagon;
    }

    /**
     * Adds a listener to the collection
     * @param listener The listener to add
     */
    public void addListener(TransferListener listener) {
        listeners.add(listener);
    }

    /**
     * Removes a listener from the collection
     * @param listener The listener to remove
     */
    public void removeListener(TransferListener listener) {
        listeners.remove(listener);
    }

    /**
     * Whether the collection already contains a listener
     * @param listener The listener to check for
     * @return whether the collection contains the listener
     */
    public boolean hasListener(TransferListener listener) {
        return listeners.contains(listener);
    }

    /**
     * Sends a transfer initated event to all listeners
     * @param resource The resource being transfered
     * @param requestType GET or PUT request
     * @see TransferEvent#TRANSFER_INITIATED
     */
    public void fireTransferInitiated(Resource resource, int requestType) {
        TransferEvent event = new TransferEvent(wagon, resource, TransferEvent.TRANSFER_INITIATED, requestType);
        for (TransferListener listener : listeners) {
            listener.transferInitiated(event);
        }
    }

    /**
     * Sends a transfer started event to all listeners
     * @param resource The resource being transfered
     * @param requestType GET or PUT request
     * @see TransferEvent#TRANSFER_STARTED
     */
    public void fireTransferStarted(Resource resource, int requestType) {
        TransferEvent event = new TransferEvent(wagon, resource, TransferEvent.TRANSFER_STARTED, requestType);
        for (TransferListener listener : listeners) {
            listener.transferStarted(event);
        }
    }

    public void fireTransferProgress(Resource resource, int requestType, byte[] buffer, int length) {
        TransferEvent event = new TransferEvent(wagon, resource, TransferEvent.TRANSFER_PROGRESS, requestType);
        for (TransferListener listener : listeners) {
            listener.transferProgress(event, buffer, length);
        }
    }

    /**
     * Sends a transfer completed event to all listeners
     * @param resource The resource being transfered
     * @param requestType GET or PUT request
     * @see TransferEvent#TRANSFER_COMPLETED
     */
    public void fireTransferCompleted(Resource resource, int requestType) {
        TransferEvent event = new TransferEvent(wagon, resource, TransferEvent.TRANSFER_COMPLETED, requestType);
        for (TransferListener listener : listeners) {
            listener.transferCompleted(event);
        }
    }

    /**
     * Sends a transfer error event to all listeners
     * @param resource The resource being transfered
     * @param requestType GET or PUT request
     * @param e The transfer error
     */
    public void fireTransferError(Resource resource, int requestType, Exception e) {
        TransferEvent event = new TransferEvent(wagon, resource, e, requestType);
        for (TransferListener listener : listeners) {
            listener.transferError(event);
        }
    }
}