// ========================================================================
// Copyright 2007 Dojo Foundation
// ------------------------------------------------------------------------
// 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.cometd;

/* ------------------------------------------------------------ */
/** Pluggable security policy for Bayeux
 *
 */
public interface SecurityPolicy
{
    /** 
     * Test if a handshake message should be accepted.
     * @param message A handshake message.
     * @return True if the handshake message should be accepted and a {@link Client} instance created
     */
    boolean canHandshake(Message message);
    
    /**
     * Test if a message should be allowed to create a new Channel
     * @param client The client sending the message. The client may be 
     * null if an anonymous publish is attempted. Server clients are 
     * indicated by {@link Client#isLocal()}
     * @param channel The channel the message is trying to create
     * @param message The message
     * @return true if the channel should be created
     */
    boolean canCreate(Client client,String channel,Message message);
    
    /**
     * Test if a client is allowed to subscribe to a channel
     * @param client The client sending the message. The client may be 
     * null if an anonymous publish is attempted. Server clients are 
     * indicated by {@link Client#isLocal()}
     * @param channel The channel the message is trying to subscribe to
     * @param messsage The message to /meta/subscribe
     * @return true if the client can subscribe to the channel
     */
    boolean canSubscribe(Client client,String channel,Message messsage);
    
    /**
     * Test if a client can publish a message to a channel
     * @param client The client sending the message. The client may be 
     * null if an anonymous publish is attempted. Server clients are 
     * indicated by {@link Client#isLocal()}
     * @param channel The channel the message is trying to publish to
     * @param messsage The message to publish
     * @return true if the client can publish to the channel.
     */
    boolean canPublish(Client client,String channel,Message messsage);
}