/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.cxf.transport.local;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;

import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.helpers.CastUtils;
import org.apache.cxf.io.CachedOutputStream;
import org.apache.cxf.message.Exchange;
import org.apache.cxf.message.ExchangeImpl;
import org.apache.cxf.message.Message;
import org.apache.cxf.message.MessageImpl;
import org.apache.cxf.transport.AbstractConduit;

public class LocalConduit extends AbstractConduit {

    public static final String IN_CONDUIT = LocalConduit.class.getName() + ".inConduit";
    public static final String RESPONSE_CONDUIT = LocalConduit.class.getName() + ".inConduit";
    public static final String IN_EXCHANGE = LocalConduit.class.getName() + ".inExchange";
    public static final String DIRECT_DISPATCH = LocalConduit.class.getName() + ".directDispatch";
    public static final String MESSAGE_FILTER_PROPERTIES = LocalConduit.class.getName() + ".filterProperties";

    private static final Logger LOG = LogUtils.getL7dLogger(LocalConduit.class);
    
    private LocalDestination destination;
    private LocalTransportFactory transportFactory;

    public LocalConduit(LocalTransportFactory transportFactory, LocalDestination destination) {
        super(destination.getAddress());
        this.destination = destination;
        this.transportFactory = transportFactory;
    }
    
    public void prepare(final Message message) throws IOException {
        if (!Boolean.TRUE.equals(message.get(DIRECT_DISPATCH))) {
            dispatchViaPipe(message);
        } else {
            // prepare the stream here
            CachedOutputStream stream = new CachedOutputStream();
            message.setContent(OutputStream.class, stream);
        }
    }

    @Override
    public void close(Message message) throws IOException {
        if (Boolean.TRUE.equals(message.get(DIRECT_DISPATCH))
            && !Boolean.TRUE.equals(message.get(Message.INBOUND_MESSAGE))) {
            dispatchDirect(message);
        } 
        
        super.close(message);
    }

    private void dispatchDirect(Message message) throws IOException {
        if (destination.getMessageObserver() == null) {
            throw new IllegalStateException("Local destination does not have a MessageObserver on address " 
                                            + destination.getAddress().getAddress().getValue());
        }

        MessageImpl copy = new MessageImpl();
        copy.put(IN_CONDUIT, this);
        copy.setDestination(destination);
        
        copy(message, copy, transportFactory.getMessageFilterProperties());
        
        CachedOutputStream stream = (CachedOutputStream)message.getContent(OutputStream.class);
        copy.setContent(InputStream.class, stream.getInputStream());

        // Create a new incoming exchange and store the original exchange for the response
        ExchangeImpl ex = new ExchangeImpl();
        ex.setInMessage(copy);
        ex.put(IN_EXCHANGE, message.getExchange());
        ex.put(LocalConduit.DIRECT_DISPATCH, true);
        ex.setDestination(destination);
        
        destination.getMessageObserver().onMessage(copy);
    }

    public static void copy(Message message, MessageImpl copy, Set<String> defaultFilter) {
        Set<String> filter = CastUtils.cast((Set)message.get(MESSAGE_FILTER_PROPERTIES));
        if (filter == null) {
            filter = defaultFilter;
        }
        
        // copy all the contents
        for (Map.Entry<String, Object> e : message.entrySet()) {
            if (!filter.contains(e.getKey())) {
                copy.put(e.getKey(), e.getValue());
            }
        }
        
        MessageImpl.copyContent(message, copy);
    }

    private void dispatchViaPipe(final Message message) throws IOException {
        final PipedInputStream stream = new PipedInputStream();
        final LocalConduit conduit = this;
        final Exchange exchange = message.getExchange();
        
        if (destination.getMessageObserver() == null) {
            throw new IllegalStateException("Local destination does not have a MessageObserver on address " 
                                            + destination.getAddress().getAddress().getValue());
        }
        
        final Runnable receiver = new Runnable() {
            public void run() {
                MessageImpl inMsg = new MessageImpl();
                inMsg.setContent(InputStream.class, stream);
                inMsg.setDestination(destination);
                inMsg.put(IN_CONDUIT, conduit);
                
                ExchangeImpl ex = new ExchangeImpl();
                ex.setInMessage(inMsg);
                ex.put(IN_EXCHANGE, exchange);
                destination.getMessageObserver().onMessage(inMsg);
            }
        };

        message.setContent(OutputStream.class, new PipedOutputStream(stream));

        // TODO: put on executor
        new Thread(receiver).start();
    }
    
    protected Logger getLogger() {
        return LOG;
    }
}
