/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/io/AbstractMessageWriter.java $
 * $Revision: 569673 $
 * $Date: 2007-08-25 06:58:51 -0700 (Sat, 25 Aug 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.io;

import java.io.IOException;
import java.util.Iterator;

import org.apache.http.Header;
import org.apache.http.HttpException;
import org.apache.http.HttpMessage;
import org.apache.http.io.HttpMessageWriter;
import org.apache.http.io.SessionOutputBuffer;
import org.apache.http.message.LineFormatter;
import org.apache.http.message.BasicLineFormatter;
import org.apache.http.params.HttpParams;
import org.apache.http.util.CharArrayBuffer;

public abstract class AbstractMessageWriter implements HttpMessageWriter {
    
    protected final SessionOutputBuffer sessionBuffer;    
    protected final CharArrayBuffer lineBuf;
    protected final LineFormatter lineFormatter;

    public AbstractMessageWriter(final SessionOutputBuffer buffer,
                                 final LineFormatter formatter,
                                 final HttpParams params) {
        super();
        if (buffer == null) {
            throw new IllegalArgumentException("Session input buffer may not be null");
        }
        this.sessionBuffer = buffer;
        this.lineBuf = new CharArrayBuffer(128);
        this.lineFormatter = (formatter != null) ?
            formatter : BasicLineFormatter.DEFAULT;
    }
    
    protected abstract void writeHeadLine(HttpMessage message)
        throws IOException
        ;

    public void write(
            final HttpMessage message) throws IOException, HttpException {
        if (message == null) {
            throw new IllegalArgumentException("HTTP message may not be null");
        }
        writeHeadLine(message);
        for (Iterator it = message.headerIterator(); it.hasNext(); ) {
            Header header = (Header) it.next();
            this.sessionBuffer.writeLine
                (lineFormatter.formatHeader(this.lineBuf, header));
        }
        this.lineBuf.clear();
        this.sessionBuffer.writeLine(this.lineBuf);
    }
    
}