/*
 *  This file is part of the Wayback archival access software
 *   (http://archive-access.sourceforge.net/projects/wayback/).
 *
 *  Licensed to the Internet Archive (IA) by one or more individual 
 *  contributors. 
 *
 *  The IA 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.
 */
package org.archive.wayback.resourcestore.resourcefile;

import java.io.IOException;
import java.util.Hashtable;
import java.util.Map;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpParser;
import org.apache.commons.httpclient.StatusLine;
import org.apache.commons.httpclient.util.EncodingUtil;
import org.archive.io.ArchiveReader;
import org.archive.io.RecoverableIOException;
import org.archive.io.arc.ARCConstants;
import org.archive.io.warc.WARCRecord;
import org.archive.wayback.core.Resource;
import org.archive.wayback.replay.HttpHeaderOperation;

public class WarcResource extends Resource {
	private WARCRecord rec = null;
	private ArchiveReader reader = null;
	private Map<String, String> headers = null;
	private long length = 0;
	private int status = 0;
	private boolean parsedHeaders = false;
	public WarcResource(WARCRecord rec, ArchiveReader reader) {
		this.rec = rec;
		this.reader = reader;
	}
	
    /**
     * @param bytes Array of bytes to examine for an EOL.
     * @return Count of end-of-line characters or zero if none.
     */
    private int getEolCharsCount(byte [] bytes) {
        int count = 0;
        if (bytes != null && bytes.length >=1 &&
                bytes[bytes.length - 1] == '\n') {
            count++;
            if (bytes.length >=2 && bytes[bytes.length -2] == '\r') {
                count++;
            }
        }
        return count;
    }

	public void parseHeaders() throws IOException {
		if(parsedHeaders) {
			return;
		}
		
        byte [] statusBytes = HttpParser.readRawLine(rec);
        int eolCharCount = getEolCharsCount(statusBytes);
        if (eolCharCount <= 0) {
            throw new RecoverableIOException("Failed to read http status where one " +
                " was expected: " + new String(statusBytes));
        }
        String statusLineStr = EncodingUtil.getString(statusBytes, 0,
            statusBytes.length - eolCharCount, ARCConstants.DEFAULT_ENCODING);
        if ((statusLineStr == null) ||
                !StatusLine.startsWithHTTP(statusLineStr)) {
           throw new RecoverableIOException("Failed parse of http status line.");
        }
        StatusLine statusLine = new StatusLine(statusLineStr);

        this.status = statusLine.getStatusCode();

        Header[] tmpHeaders = HttpParser.parseHeaders(rec,
                ARCConstants.DEFAULT_ENCODING);
        headers = new Hashtable<String,String>();
		this.setInputStream(rec);
        for(Header header: tmpHeaders) {
        	headers.put(header.getName(), header.getValue());
			if(header.getName().toUpperCase().contains(
					HttpHeaderOperation.HTTP_TRANSFER_ENC_HEADER)) {
				if(header.getValue().toUpperCase().contains(
						HttpHeaderOperation.HTTP_CHUNKED_ENCODING_HEADER)) {
					setChunkedEncoding();
				}
			}
        }
		parsedHeaders = true;
	}
	
	
	@Override
	public Map<String, String> getHttpHeaders() {
		return headers;
	}

	@Override
	public long getRecordLength() {
		// TODO Auto-generated method stub
		return length;
	}

	@Override
	public int getStatusCode() {
		return status;
	}

	@Override
	public void close() throws IOException {
		rec.close();
		reader.close();
	}
}