/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2012, Red Hat, Inc. and/or its affiliates or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat, Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.search.bridge.builtin;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.net.URI;
import java.sql.Blob;
import java.sql.SQLException;

import org.apache.lucene.document.Document;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.sax.WriteOutContentHandler;

import org.hibernate.search.bridge.FieldBridge;
import org.hibernate.search.bridge.LuceneOptions;
import org.hibernate.search.bridge.TikaMetadataProcessor;
import org.hibernate.search.bridge.TikaParseContextProvider;
import org.hibernate.search.util.impl.ClassLoaderHelper;
import org.hibernate.search.util.logging.impl.Log;
import org.hibernate.search.util.logging.impl.LoggerFactory;

import static com.google.common.base.Throwables.propagate;
import static org.apache.tika.io.IOUtils.closeQuietly;

/**
 * Bridge implementation which uses Apache Tika to extract data from provided input.
 *
 * @author Hardy Ferentschik
 */
public class TikaBridge implements FieldBridge {
	private static final Log log = LoggerFactory.make();

	private TikaMetadataProcessor metadataProcessor;
	private TikaParseContextProvider parseContextProvider;

	public TikaBridge() {
		setMetadataProcessorClass( null );
		setParseContextProviderClass( null );
	}

	public void setParseContextProviderClass(Class<?> parseContextProviderClass) {
		if ( parseContextProviderClass == null ) {
			parseContextProvider = new NoopParseContextProvider();
		}
		else {
			parseContextProvider = ClassLoaderHelper.instanceFromClass(
					TikaParseContextProvider.class,
					parseContextProviderClass,
					"Tika metadata processor"
			);
		}
	}

	public void setMetadataProcessorClass(Class<?> metadataProcessorClass) {
		if ( metadataProcessorClass == null ) {
			metadataProcessor = new NoopTikaMetadataProcessor();
		}
		else {
			metadataProcessor = ClassLoaderHelper.instanceFromClass(
					TikaMetadataProcessor.class,
					metadataProcessorClass,
					"Tika parse context provider"
			);
		}
	}

	@Override
	public void set(String name, Object value, Document document, LuceneOptions luceneOptions) {
		if ( value == null ) {
			throw new IllegalArgumentException( "null cannot be passed to Tika bridge" );
		}
		InputStream in = null;
		try {
			in = getInputStreamForData( value );

			Metadata metadata = metadataProcessor.prepareMetadata();
			ParseContext parseContext = parseContextProvider.getParseContext( name, value );

			StringWriter writer = new StringWriter();
			WriteOutContentHandler contentHandler = new WriteOutContentHandler( writer );

			Parser parser = new AutoDetectParser();
			parser.parse( in, contentHandler, metadata, parseContext );
			luceneOptions.addFieldToDocument( name, writer.toString(), document );

			// allow for optional indexing of metadata by the user
			metadataProcessor.set( name, value, document, luceneOptions, metadata );
		}
		catch ( Exception e ) {
			throw propagate( e );
		}
		finally {
			closeQuietly( in );
		}
	}

	private InputStream getInputStreamForData(Object object) throws Exception {
		InputStream in;
		if ( object instanceof Blob ) {
			try {
				in = ( ( Blob ) object ).getBinaryStream();
			}
			catch ( SQLException e ) {
				throw log.unableToGetInputStreamFromBlob( e );
			}
		}
		else if ( object instanceof byte[] ) {
			byte[] data = ( byte[] ) object;
			in = new ByteArrayInputStream( data );
		}
		else if ( object instanceof String ) {
			String path = ( String ) object;
			File file = new File( path );
			in = openInputStream( file );
		}
		else if ( object instanceof URI ) {
			URI uri = ( URI ) object;
			File file = new File( uri );
			in = openInputStream( file );
		}
		else {
			throw log.unsupportedTikaBridgeType();
		}
		return in;
	}

	private FileInputStream openInputStream(File file) throws IOException {
		if ( file.exists() ) {
			if ( file.isDirectory() ) {
				throw log.fileIsADirectory( file.toString() );
			}
			if ( !file.canRead() ) {
				throw log.fileIsNotReadable( file.toString() );
			}
		}
		else {
			throw log.fileDoesNotExist( file.toString() );
		}
		return new FileInputStream( file );
	}

	private static class NoopTikaMetadataProcessor implements TikaMetadataProcessor {
		@Override
		public Metadata prepareMetadata() {
			return new Metadata();
		}

		@Override
		public void set(String name, Object value, Document document, LuceneOptions luceneOptions, Metadata metadata) {
		}
	}

	private static class NoopParseContextProvider implements TikaParseContextProvider {
		@Override
		public ParseContext getParseContext(String name, Object value) {
			return new ParseContext();
		}
	}
}