//bzipParser.java
//------------------------
//part of YaCy
//(C) by Michael Peter Christen; mc@yacy.net
//first published on http://www.anomic.de
//Frankfurt, Germany, 2005
//
//this file is contributed by Martin Thelian
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
//This program is free software; you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2 of the License, or
//(at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

package net.yacy.document.parser;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.util.Date;
import java.util.Set;

import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.commons.compress.compressors.bzip2.BZip2Utils;

import net.yacy.cora.document.id.DigestURL;
import net.yacy.cora.document.id.MultiProtocolURL;
import net.yacy.document.AbstractParser;
import net.yacy.document.Document;
import net.yacy.document.Parser;
import net.yacy.document.TextParser;
import net.yacy.document.VocabularyScraper;
import net.yacy.kelondro.util.FileUtils;

/**
 * Parses a bz2 archive.
 * Unzips and parses the content and adds it to the created main document
 */
public class bzipParser extends AbstractParser implements Parser {
	
    public bzipParser() {
        super("Bzip 2 UNIX Compressed File Parser");
        this.SUPPORTED_EXTENSIONS.add("bz2");
        this.SUPPORTED_EXTENSIONS.add("tbz");
        this.SUPPORTED_EXTENSIONS.add("tbz2");
        this.SUPPORTED_MIME_TYPES.add("application/x-bzip2");
        this.SUPPORTED_MIME_TYPES.add("application/bzip2");
        this.SUPPORTED_MIME_TYPES.add("application/x-bz2");
        this.SUPPORTED_MIME_TYPES.add("application/x-bzip");
        this.SUPPORTED_MIME_TYPES.add("application/x-stuffit");
    }

    @Override
    public Document[] parse(
            final DigestURL location,
            final String mimeType,
            final String charset,
            Set<String> ignore_class_name,
            final VocabularyScraper scraper, 
            final int timezoneOffset,
            final InputStream source)
            throws Parser.Failure, InterruptedException {

        File tempFile = null;
        Document maindoc = null;
        int read = 0;
        final byte[] data = new byte[1024];
        BZip2CompressorInputStream zippedContent = null;
        FileOutputStream out = null;
        try {
            // BZip2CompressorInputStream checks filecontent (magic start-bytes "BZh") and throws ioexception if no match
            zippedContent = new BZip2CompressorInputStream(source);

            tempFile = File.createTempFile("bunzip","tmp");

            // creating a temp file to store the uncompressed data
            out = new FileOutputStream(tempFile);

            // reading bzip file and store it uncompressed
            while((read = zippedContent.read(data, 0, 1024)) != -1) {
                out.write(data, 0, read);
            }
            out.close();
            out = null;

        } catch(Exception e) {
        	if (tempFile != null) {
        		FileUtils.deletedelete(tempFile);
        	}
        	throw new Parser.Failure("Unexpected error while parsing bzip file. " + e.getMessage(), location);
        } finally {
        	if(zippedContent != null) {
        		try {
					zippedContent.close();
				} catch (IOException ignored) {
					log.warn("Could not close bzip input stream");
				}
        	}
        	if(out != null) {
        		try {
					out.close();
				} catch (IOException e) {
					throw new Parser.Failure("Unexpected error while parsing bzip file. " + e.getMessage(), location);
				}
        	}
        }
        try {
             // create maindoc for this bzip container, register with supplied url & mime
            maindoc = createMainDocument(location, mimeType, charset, this);
            // creating a new parser class to parse the unzipped content
            final String contentfilename = BZip2Utils.getUncompressedFilename(location.getFileName());
            final String mime = TextParser.mimeOf(MultiProtocolURL.getFileExtension(contentfilename));
            final Document[] docs = TextParser.parseSource(location, mime, null, ignore_class_name, scraper, timezoneOffset, 999, tempFile);
            if (docs != null) maindoc.addSubDocuments(docs);
        } catch (final Exception e) {
            if (e instanceof InterruptedException) throw (InterruptedException) e;
            if (e instanceof Parser.Failure) throw (Parser.Failure) e;

            throw new Parser.Failure("Unexpected error while parsing bzip file. " + e.getMessage(),location);
        } finally {
            if (tempFile != null) FileUtils.deletedelete(tempFile);
        }
        return maindoc == null ? null : new Document[]{maindoc};
    }
    
    @Override
    public boolean isParseWithLimitsSupported() {
    	return true;
    }
    
    /**
     * Create the main resulting parsed document for a bzip archive
     * @param location the parsed resource URL
     * @param mimeType the media type of the resource
     * @param charset the charset name if known
     * @param an instance of bzipParser that is registered as the parser origin of the document
     * @return a Document instance
     */
	public static Document createMainDocument(final DigestURL location, final String mimeType, final String charset, final bzipParser parser) {
		final String filename = location.getFileName();
		Document maindoc = new Document(
                location,
                mimeType,
                charset,
                parser,
                null,
                null,
                AbstractParser.singleList(filename.isEmpty() ? location.toTokens() : MultiProtocolURL.unescape(filename)), // title
                null,
                null,
                null,
                null,
                0.0d, 0.0d,
                (Object) null,
                null,
                null,
                null,
                false,
                new Date());
		return maindoc;
	}
	
	/**
	 * Parse content in an open stream uncompressing on the fly a bzipped resource.
	 * @param location the URL of the bzipped resource 
	 * @param charset the charset name if known
	 * @param timezoneOffset the local time zone offset
	 * @param compressedInStream an open stream uncompressing on the fly the compressed content
	 * @param maxLinks
	 *            the maximum total number of links to parse and add to the
	 *            result documents
	 * @param maxBytes
	 *            the maximum number of content bytes to process
	 * @return a list of documents that result from parsing the source, with
	 *         empty or null text.
	 * @throws Parser.Failure
	 *             when the parser processing failed
	 */
	public Document[] parseCompressedInputStream(final DigestURL location, final String charset, final int timezoneOffset, final int depth,
			final InputStream compressedInStream, final int maxLinks, final long maxBytes) throws Failure {
        // creating a new parser class to parse the unzipped content
		final String compressedFileName = location.getFileName();
        final String contentfilename = BZip2Utils.getUncompressedFilename(compressedFileName);
        final String mime = TextParser.mimeOf(MultiProtocolURL.getFileExtension(contentfilename));
        try {
        	/* Use the uncompressed file name for sub parsers to not unnecessarily use again the gzipparser */
    		final String locationPath = location.getPath();
        	final String contentPath = locationPath.substring(0, locationPath.length() - compressedFileName.length()) + contentfilename;
			final DigestURL contentLocation = new DigestURL(location.getProtocol(), location.getHost(), location.getPort(), contentPath);
			
	        /* Rely on the supporting parsers to respect the maxLinks and maxBytes limits on compressed content */
	        return TextParser.parseWithLimits(contentLocation, mime, charset, timezoneOffset, depth, -1, compressedInStream, maxLinks, maxBytes);
		} catch (MalformedURLException e) {
			throw new Parser.Failure("Unexpected error while parsing gzip file. " + e.getMessage(), location);
		}
	}
		
    
    @Override
    public Document[] parseWithLimits(final DigestURL location, final String mimeType, final String charset, final VocabularyScraper scraper,
    		final int timezoneOffset, final InputStream source, final int maxLinks, final long maxBytes)
    		throws Parser.Failure {
        Document maindoc = null;
        BZip2CompressorInputStream zippedContent = null;
        try {
            // BZip2CompressorInputStream checks filecontent (magic start-bytes "BZh") and throws ioexception if no match
            zippedContent = new BZip2CompressorInputStream(source);

        } catch(Exception e) {
        	throw new Parser.Failure("Unexpected error while parsing bzip file. " + e.getMessage(), location);
        } 
        
        try {
             // create maindoc for this bzip container, register with supplied url & mime
            maindoc = createMainDocument(location, mimeType, charset, this);
            // creating a new parser class to parse the unzipped content
            final Document[] docs = parseCompressedInputStream(location, null, timezoneOffset, 999, zippedContent, maxLinks, maxBytes);
            if (docs != null) {
            	maindoc.addSubDocuments(docs);
            	if(docs.length > 0 && docs[0].isPartiallyParsed()) {
            		maindoc.setPartiallyParsed(true);
            	}
            }
        } catch (final Exception e) {
            if (e instanceof Parser.Failure) {
            	throw (Parser.Failure) e;
            }

            throw new Parser.Failure("Unexpected error while parsing bzip file. " + e.getMessage(),location);
        }
        return maindoc == null ? null : new Document[]{maindoc};
    }
}