/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/conn/DefaultResponseParser.java $
 * $Revision: 617638 $
 * $Date: 2008-02-01 12:49:26 -0800 (Fri, 01 Feb 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.impl.conn;

import java.io.IOException;

import org.apache.http.HttpException;
import org.apache.http.HttpMessage;
import org.apache.http.HttpResponseFactory;
import org.apache.http.NoHttpResponseException;
import org.apache.http.ProtocolException;
import org.apache.http.StatusLine;
import org.apache.http.conn.params.ConnConnectionPNames;
import org.apache.http.impl.io.AbstractMessageParser;
import org.apache.http.io.SessionInputBuffer;
import org.apache.http.message.LineParser;
import org.apache.http.message.ParserCursor;
import org.apache.http.params.HttpParams;
import org.apache.http.util.CharArrayBuffer;

public class DefaultResponseParser extends AbstractMessageParser {
    
    private final HttpResponseFactory responseFactory;
    private final CharArrayBuffer lineBuf;
    private final int maxGarbageLines;
    
    public DefaultResponseParser(
            final SessionInputBuffer buffer,
            final LineParser parser,
            final HttpResponseFactory responseFactory,
            final HttpParams params) {
        super(buffer, parser, params);
        if (responseFactory == null) {
            throw new IllegalArgumentException
                ("Response factory may not be null");
        }
        this.responseFactory = responseFactory;
        this.lineBuf = new CharArrayBuffer(128);
        this.maxGarbageLines = params.getIntParameter(
            ConnConnectionPNames.MAX_STATUS_LINE_GARBAGE, Integer.MAX_VALUE);
    }


    @Override
    protected HttpMessage parseHead(
            final SessionInputBuffer sessionBuffer) throws IOException, HttpException {
        // clear the buffer
        this.lineBuf.clear();
        //read out the HTTP status string
        int count = 0;
        ParserCursor cursor = null;
        do {
            int i = sessionBuffer.readLine(this.lineBuf);
            if (i == -1 && count == 0) {
                // The server just dropped connection on us
                throw new NoHttpResponseException("The target server failed to respond");
            }
            cursor = new ParserCursor(0, this.lineBuf.length());
            if (lineParser.hasProtocolVersion(this.lineBuf, cursor)) {
                // Got one
                break;
            } else if (i == -1 || count >= this.maxGarbageLines) {
                // Giving up
                throw new ProtocolException("The server failed to respond with a " +
                        "valid HTTP response");
            }
            count++;
        } while(true);
        //create the status line from the status string
        StatusLine statusline = lineParser.parseStatusLine(this.lineBuf, cursor);
        return this.responseFactory.newHttpResponse(statusline, null);
    }

}