/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/client/methods/HttpRequestBase.java $
 * $Revision: 674186 $
 * $Date: 2008-07-05 05:18:54 -0700 (Sat, 05 Jul 2008) $
 *
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.client.methods;

import java.io.IOException;
import java.net.URI;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import org.apache.http.ProtocolVersion;
import org.apache.http.RequestLine;
import org.apache.http.client.utils.CloneUtils;
import org.apache.http.conn.ClientConnectionRequest;
import org.apache.http.conn.ConnectionReleaseTrigger;
import org.apache.http.message.AbstractHttpMessage;
import org.apache.http.message.BasicRequestLine;
import org.apache.http.message.HeaderGroup;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;

/**
 * Basic implementation of an HTTP request that can be modified.
 *
 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
 *
 * @version $Revision: 674186 $
 * 
 * @since 4.0
 */
public abstract class HttpRequestBase extends AbstractHttpMessage 
    implements HttpUriRequest, AbortableHttpRequest, Cloneable {

    private Lock abortLock;

    private boolean aborted;
    
    private URI uri;
    private ClientConnectionRequest connRequest;
    private ConnectionReleaseTrigger releaseTrigger;
    
    public HttpRequestBase() {
        super();
        this.abortLock = new ReentrantLock();
    }

    public abstract String getMethod();

    public ProtocolVersion getProtocolVersion() {
        return HttpProtocolParams.getVersion(getParams());
    }

    public URI getURI() {
        return this.uri;
    }
    
    public RequestLine getRequestLine() {
        String method = getMethod();
        ProtocolVersion ver = getProtocolVersion();
        URI uri = getURI();
        String uritext = null;
        if (uri != null) {
            uritext = uri.toASCIIString();
        }
        if (uritext == null || uritext.length() == 0) {
            uritext = "/";
        }
        return new BasicRequestLine(method, uritext, ver);
    }

    public void setURI(final URI uri) {
        this.uri = uri;
    }

    public void setConnectionRequest(final ClientConnectionRequest connRequest)
            throws IOException {
        this.abortLock.lock();
        try {
            if (this.aborted) {
                throw new IOException("Request already aborted");
            }
            
            this.releaseTrigger = null;
            this.connRequest = connRequest;
        } finally {
            this.abortLock.unlock();
        }
    }

    public void setReleaseTrigger(final ConnectionReleaseTrigger releaseTrigger)
            throws IOException {
        this.abortLock.lock();
        try {
            if (this.aborted) {
                throw new IOException("Request already aborted");
            }
            
            this.connRequest = null;
            this.releaseTrigger = releaseTrigger;
        } finally {
            this.abortLock.unlock();
        }
    }
    
    public void abort() {
        ClientConnectionRequest localRequest;
        ConnectionReleaseTrigger localTrigger;
        
        this.abortLock.lock();
        try {
            if (this.aborted) {
                return;
            }            
            this.aborted = true;
            
            localRequest = connRequest;
            localTrigger = releaseTrigger;
        } finally {
            this.abortLock.unlock();
        }        

        // Trigger the callbacks outside of the lock, to prevent
        // deadlocks in the scenario where the callbacks have
        // their own locks that may be used while calling
        // setReleaseTrigger or setConnectionRequest.
        if (localRequest != null) {
            localRequest.abortRequest();
        }
        if (localTrigger != null) {
            try {
                localTrigger.abortConnection();
            } catch (IOException ex) {
                // ignore
            }
        }
    }
    
    public boolean isAborted() {
        return this.aborted;
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        HttpRequestBase clone = (HttpRequestBase) super.clone();
        clone.abortLock = new ReentrantLock();
        clone.aborted = false;
        clone.releaseTrigger = null;
        clone.connRequest = null;
        clone.headergroup = (HeaderGroup) CloneUtils.clone(this.headergroup);
        clone.params = (HttpParams) CloneUtils.clone(this.params);
        return clone;
    }
    
}