/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *                               ***
 *
 *   Community License: GPL 3.0
 *
 *   This file is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published
 *   by the Free Software Foundation, either version 3 of the License,
 *   or (at your option) any later version.
 *
 *   This file is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 *                               ***
 *
 *   Available Commercial License: GraniteDS SLA 1.0
 *
 *   This is the appropriate option if you are creating proprietary
 *   applications and you are not prepared to distribute and share the
 *   source code of your application under the GPL v3 license.
 *
 *   Please visit http://www.granitedataservices.com/license for more
 *   details.
 */
package org.granite.client.tide;

import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.nio.charset.Charset;
import java.util.Observable;
import java.util.Observer;
import java.util.concurrent.Future;

import org.granite.client.messaging.messages.responses.FaultMessage;
import org.granite.client.messaging.messages.responses.FaultMessage.Code;
import org.granite.client.tide.impl.ComponentImpl;
import org.granite.client.tide.server.ExceptionHandler;
import org.granite.client.tide.server.ServerSession;
import org.granite.client.tide.server.SimpleTideResponder;
import org.granite.client.tide.server.TideFaultEvent;
import org.granite.client.tide.server.TideResponder;
import org.granite.client.tide.server.TideResultEvent;


public abstract class BaseIdentity extends ComponentImpl implements Identity, ExceptionHandler {
        
        private boolean loggedIn;
        private String username;
        private PropertyChangeSupport pcs = new PropertyChangeSupport(this);

        public boolean isLoggedIn() {
                return loggedIn;
        }
        
        public void setLoggedIn(boolean loggedIn) {
                if (loggedIn == this.loggedIn)
                        return;
                
                this.loggedIn = loggedIn;
                if (loggedIn)
                        getServerSession().afterLogin();
                else
                        setUsername(null);
                
                pcs.firePropertyChange("loggedIn", !loggedIn, loggedIn);
        }
        
        public String getUsername() {
                return username;
        }
        
        protected void setUsername(String username) {
                String oldUsername = this.username;
                this.username = username;
                
                if ((username == null && oldUsername != null) || (username != null && !username.equals(oldUsername)))
                        pcs.firePropertyChange("username", oldUsername, username);
        }
        
    
    public BaseIdentity(final ServerSession serverSession) {
        super(serverSession);
        
        loggedIn = false;
    }
    
    /**
     *  Triggers a remote call to check is user is currently logged in
     *  Can be used at application startup to handle browser refresh cases
     * 
     *  @param tideResponder a responder for the remote call
     *  @return future result returning the username if logged in or null
     */
    public Future<String> checkLoggedIn(final TideResponder<String> tideResponder) {
        return super.call("isLoggedIn", new SimpleTideResponder<String>() {
                        @Override
                        public void result(TideResultEvent<String> event) {
                                if (event.getResult() != null) {
                                        setUsername(event.getResult());
                                        setLoggedIn(true);
                                }
                                else if (isLoggedIn()) {
                                        setLoggedIn(false);
                                        
                                        // Session expired, directly mark the channel as logged out
                                        getServerSession().sessionExpired();
                                }
                                
                                if (tideResponder != null)
                                        tideResponder.result(event);
                        }
                        
                        @Override
                        public void fault(TideFaultEvent event) {
                                if (event.getFault().getCode() == Code.ACCESS_DENIED) {
                                        // Not in role for the destination
                                        setLoggedIn(false);
                                        
                                        getServerSession().logout(null);
                                }
                                
                                if (tideResponder != null)
                                        tideResponder.fault(event);
                        }
        });
    }
    
    
    public void login(final String username, String password, final TideResponder<String> tideResponder) {
        getServerSession().login(username, password);
        
        clearSecurityCache();
        
        try {
            // Force synchronous operation to prevent issues with Spring session fixation protection
            // so next remote calls use the correct session id
            checkLoggedIn(tideResponder).get();
        }
        catch (Exception e) {
        }
    }

    public void login(final String username, String password, Charset charset, final TideResponder<String> tideResponder) {
        getServerSession().login(username, password, charset);
        
        clearSecurityCache();
        
        try {
            // Force synchronous operation to prevent issues with Spring session fixation protection
            // so next remote calls use the correct session id
            checkLoggedIn(tideResponder).get();
        }
        catch (Exception e) {
        }
    }
    
    
    public void logout(final TideResponder<Void> tideResponder) {
        final Observer observer = new Observer() {
                        @SuppressWarnings("unchecked")
                        @Override
                        public void update(Observable logout, Object event) {
                        setLoggedIn(false);
                        
                        if (tideResponder != null) {
                                        if (event instanceof TideResultEvent)
                                        tideResponder.result((TideResultEvent<Void>)event);
                                        else if (event instanceof TideFaultEvent)
                                        tideResponder.fault((TideFaultEvent)event);
                        }
                        }
        };
        
        getServerSession().logout(observer);
    }

    
        @Override
        public boolean accepts(FaultMessage emsg) {
                return emsg.getCode() == Code.NOT_LOGGED_IN;
        }

        @Override
        public void handle(Context context, FaultMessage emsg, TideFaultEvent faultEvent) {
                if (isLoggedIn()) {
                        setLoggedIn(false);
                        
                        // Session expired, directly mark the channel as logged out
                        getServerSession().sessionExpired();
                }
        }
        
        
        public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
                pcs.addPropertyChangeListener(propertyName, listener);
        }
        
        public void removePropertyChangeListener(String propertyName, PropertyChangeListener listener) {
                pcs.removePropertyChangeListener(propertyName, listener);
        }
        
        public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) {
                pcs.firePropertyChange(propertyName, oldValue, newValue);
        }
        
    /**
     *  Clear the security cache
     */
    public void clearSecurityCache() {        
    }
}