/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/entity/EntitySerializer.java $
 * $Revision: 560343 $
 * $Date: 2007-07-27 11:18:19 -0700 (Fri, 27 Jul 2007) $
 *
 * ====================================================================
 * 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.impl.entity;

import java.io.IOException;
import java.io.OutputStream;

import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpMessage;
import org.apache.http.entity.ContentLengthStrategy;
import org.apache.http.impl.io.ChunkedOutputStream;
import org.apache.http.impl.io.ContentLengthOutputStream;
import org.apache.http.impl.io.IdentityOutputStream;
import org.apache.http.io.SessionOutputBuffer;

/**
 * Default implementation of an entity serializer.
 * <p>
 * This entity serializer currently supports only "chunked" and "identitiy" transfer-coding</a>
 * </p>
 * 
 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
 *
 * @version $Revision: 560343 $
 * 
 * @since 4.0
 */
public class EntitySerializer {

    private final ContentLengthStrategy lenStrategy;
    
    public EntitySerializer(final ContentLengthStrategy lenStrategy) {
        super();
        if (lenStrategy == null) {
            throw new IllegalArgumentException("Content length strategy may not be null");
        }
        this.lenStrategy = lenStrategy;
    }

    protected OutputStream doSerialize(
            final SessionOutputBuffer outbuffer,
            final HttpMessage message) throws HttpException, IOException {
        long len = this.lenStrategy.determineLength(message);
        if (len == ContentLengthStrategy.CHUNKED) {
            return new ChunkedOutputStream(outbuffer);
        } else if (len == ContentLengthStrategy.IDENTITY) {
            return new IdentityOutputStream(outbuffer);
        } else {
            return new ContentLengthOutputStream(outbuffer, len);
        }
    }

    public void serialize(
            final SessionOutputBuffer outbuffer,
            final HttpMessage message,
            final HttpEntity entity) throws HttpException, IOException {
        if (outbuffer == null) {
            throw new IllegalArgumentException("Session output buffer may not be null");
        }
        if (message == null) {
            throw new IllegalArgumentException("HTTP message may not be null");
        }
        if (entity == null) {
            throw new IllegalArgumentException("HTTP entity may not be null");
        }
        OutputStream outstream = doSerialize(outbuffer, message);
        entity.writeTo(outstream);
        outstream.close();
    }
    
}