/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.threading;

import java.io.File;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;

import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.stream.StreamResult;

import org.xml.sax.ContentHandler;

import org.apache.commons.io.FilenameUtils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.fop.activity.Initializable;
import org.apache.fop.apps.FOPException;
import org.apache.fop.apps.FOUserAgent;
import org.apache.fop.apps.FopFactory;
import org.apache.fop.apps.MimeConstants;
import org.apache.fop.configuration.Configurable;
import org.apache.fop.configuration.Configuration;
import org.apache.fop.configuration.ConfigurationException;
import org.apache.fop.render.intermediate.IFDocumentHandler;
import org.apache.fop.render.intermediate.IFException;
import org.apache.fop.render.intermediate.IFParser;
import org.apache.fop.render.intermediate.IFUtil;

/**
 * Implementation of the {@link Processor} interface that renders IF XML to a final output format.
 */
public class IFProcessorImpl
            implements Processor, Configurable, Initializable {

    private static final Log LOGGER = LogFactory.getLog(IFProcessorImpl.class);


    private FopFactory fopFactory;
    private TransformerFactory factory = TransformerFactory.newInstance();
    private String userconfig;
    private String mime;
    private String fileExtension;

    /** {@inheritDoc} */
    public void configure(Configuration configuration) throws ConfigurationException {
        this.userconfig = configuration.getChild("userconfig").getValue(null);
        this.mime = configuration.getChild("mime").getValue(MimeConstants.MIME_PDF);
        this.fileExtension = configuration.getChild("extension").getValue(".pdf");
    }

    /** {@inheritDoc} */
    public void initialize() throws Exception {
        if (this.userconfig != null) {
            LOGGER.debug("Setting user config: " + userconfig);
            fopFactory = FopFactory.newInstance(new File(this.userconfig));
        } else {
            fopFactory = FopFactory.newInstance(new File(".").toURI());
        }
    }

    /** {@inheritDoc}
     * @throws IFException */
    public void process(Source src, Templates templates, OutputStream out)
                throws org.apache.fop.apps.FOPException, java.io.IOException, IFException {
        FOUserAgent foUserAgent = fopFactory.newFOUserAgent();
        try {
            URL url = new URL(src.getSystemId());
            String filename = FilenameUtils.getName(url.getPath());
            foUserAgent.getEventBroadcaster().addEventListener(
                    new AvalonAdapter(LOGGER, filename));
        } catch (MalformedURLException mfue) {
            throw new RuntimeException(mfue);
        }

        //Setup target handler
        IFDocumentHandler targetHandler = fopFactory.getRendererFactory().createDocumentHandler(
                foUserAgent, mime);

        //Setup fonts
        IFUtil.setupFonts(targetHandler);
        targetHandler.setResult(new StreamResult(out));

        try {
            Transformer transformer;
            if (templates == null) {
                transformer = factory.newTransformer();
            } else {
                transformer = templates.newTransformer();
            }
            IFParser parser = new IFParser();
            ContentHandler contentHandler = parser.getContentHandler(targetHandler, foUserAgent);
            Result res = new SAXResult(contentHandler);
            transformer.transform(src, res);
        } catch (TransformerException e) {
            throw new FOPException(e);
        }
    }

    /** {@inheritDoc} */
    public String getTargetFileExtension() {
        return this.fileExtension;
    }

}
