/*
 *  Copyright 1999-2004 The Apache Software 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.apache.jk.common;

import java.io.IOException;

import org.apache.jk.core.JkHandler;
import org.apache.jk.core.Msg;
import org.apache.jk.core.MsgContext;




/**
 * Dispatch based on the message type. ( XXX make it more generic,
 * now it's specific to ajp13 ).
 * 
 * @author Costin Manolache
 */
public class HandlerDispatch extends JkHandler
{
    private static org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog( HandlerDispatch.class );

    public HandlerDispatch() 
    {
    }

    public void init() {
    }

    JkHandler handlers[]=new JkHandler[MAX_HANDLERS];
    String handlerNames[]=new String[MAX_HANDLERS];
    
    static final int MAX_HANDLERS=32;    
    static final int RESERVED=16;  // reserved names, backward compat
    int currentId=RESERVED;

    public int registerMessageType( int id, String name, JkHandler h,
                                    String sig[] )
    {
        if( log.isDebugEnabled() )
            log.debug( "Register message " + id + " " + h.getName() +
                 " " + h.getClass().getName());
	if( id < 0 ) {
	    // try to find it by name
	    for( int i=0; i< handlerNames.length; i++ ) {
                if( handlerNames[i]==null ) continue;
                if( name.equals( handlerNames[i] ) )
                    return i;
            }
	    handlers[currentId]=h;
            handlerNames[currentId]=name;
	    currentId++;
	    return currentId;
	}
	handlers[id]=h;
        handlerNames[currentId]=name;
	return id;
    }

    
    // -------------------- Incoming message --------------------

    public int invoke(Msg msg, MsgContext ep ) 
        throws IOException
    {
        int type=msg.peekByte();
        ep.setType( type );
        
        if( type > handlers.length ||
            handlers[type]==null ) {
	    if( log.isDebugEnabled() )
                log.debug( "Invalid handler " + type );
	    return ERROR;
	}

        if( log.isDebugEnabled() )
            log.debug( "Received " + type + " " + handlers[type].getName());
        
	JkHandler handler=handlers[type];
        
        return handler.invoke( msg, ep );
    }

 }
