/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/entity/EntityDeserializer.java $
 * $Revision: 560358 $
 * $Date: 2007-07-27 12:30:42 -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 org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpMessage;
import org.apache.http.entity.BasicHttpEntity;
import org.apache.http.entity.ContentLengthStrategy;
import org.apache.http.impl.io.ChunkedInputStream;
import org.apache.http.impl.io.ContentLengthInputStream;
import org.apache.http.impl.io.IdentityInputStream;
import org.apache.http.io.SessionInputBuffer;
import org.apache.http.protocol.HTTP;

/**
 * Default implementation of an entity deserializer.
 * <p>
 * This entity deserializer currently supports only "chunked" and "identitiy" transfer-coding</a>
 * </p>
 * 
 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
 *
 * @version $Revision: 560358 $
 * 
 * @since 4.0
 */
public class EntityDeserializer {

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

    protected BasicHttpEntity doDeserialize(
            final SessionInputBuffer inbuffer,
            final HttpMessage message) throws HttpException, IOException {
        BasicHttpEntity entity = new BasicHttpEntity();
        
        long len = this.lenStrategy.determineLength(message);
        if (len == ContentLengthStrategy.CHUNKED) {
            entity.setChunked(true);
            entity.setContentLength(-1);
            entity.setContent(new ChunkedInputStream(inbuffer));
        } else if (len == ContentLengthStrategy.IDENTITY) {
            entity.setChunked(false);
            entity.setContentLength(-1);
            entity.setContent(new IdentityInputStream(inbuffer));                            
        } else {
            entity.setChunked(false);
            entity.setContentLength(len);
            entity.setContent(new ContentLengthInputStream(inbuffer, len));
        }
        
        Header contentTypeHeader = message.getFirstHeader(HTTP.CONTENT_TYPE);
        if (contentTypeHeader != null) {
            entity.setContentType(contentTypeHeader);    
        }
        Header contentEncodingHeader = message.getFirstHeader(HTTP.CONTENT_ENCODING);
        if (contentEncodingHeader != null) {
            entity.setContentEncoding(contentEncodingHeader);    
        }
        return entity;
    }
        
    public HttpEntity deserialize(
            final SessionInputBuffer inbuffer,
            final HttpMessage message) throws HttpException, IOException {
        if (inbuffer == null) {
            throw new IllegalArgumentException("Session input buffer may not be null");
        }
        if (message == null) {
            throw new IllegalArgumentException("HTTP message may not be null");
        }
        return doDeserialize(inbuffer, message);
    }
    
}