/**
 * Copyright 2010 JBoss Inc
 *
 * 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.drools.guvnor.client.rpc;

import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.core.client.GWT;

import java.util.List;
import java.util.ArrayList;

import org.drools.guvnor.client.common.GenericCallback;

/**
 * This manages "subscriptions" for when messages are pushed from the server.
 * @author Michael Neale
 */
public class PushClient {


    private static final PushClient INSTANCE = new PushClient();

    public static PushClient instance() {
        return INSTANCE;
    }
    
    private PushClient() {
    }

    private List<ServerPushNotification> callbacks = new ArrayList<ServerPushNotification>();
    private boolean connected = false;

    public void subscribe(ServerPushNotification pushed) {
        if (!connected) connect();
        callbacks.add(pushed);
    }

    private void connect() {
        connected = true;
        
        System.err.println("Connecting" + System.currentTimeMillis());
        Timer timer = new Timer() {

            public void run() {
                RepositoryServiceFactory.getService().subscribe(new AsyncCallback<List<PushResponse>>() {
                    public void onFailure(Throwable caught) {
                        System.err.println("FAIL" + System.currentTimeMillis());
                    }

                    public void onSuccess(List<PushResponse> result) {
                        //System.err.println("Got response !" + System.currentTimeMillis());
                        processResult(result);
                    }
                });
            }

        };

        timer.scheduleRepeating( 60000 );
/*        
        RepositoryServiceFactory.getService().subscribe(new AsyncCallback<List<PushResponse>>() {
            public void onFailure(Throwable caught) {
                System.err.println("FAIL" + System.currentTimeMillis());
                
                connect();
            }

            public void onSuccess(List<PushResponse> result) {
                System.err.println("Got response !" + System.currentTimeMillis());
                processResult(result);
                connect();
            }
        });*/

    }

    private void processResult(List<PushResponse> result) {
        if (result == null) {
            System.err.println("NULL result :(");
            return;
        }
        for (PushResponse msg: result) {
            System.err.println("Processing pushed message:" + msg.messageType + "," + msg.message);
            for (ServerPushNotification pn : callbacks) {
                System.err.println("performing callback...");
                pn.messageReceived(msg);
            }
        }
    }

    public void unsubscribe(ServerPushNotification pushed) {
        callbacks.remove(pushed);
    }

}