/*******************************************************************************
 * Copyright 2010 Simon Mieth
 * 
 * Licensed 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.kabeja.xslt;

import java.io.FileReader;
import java.util.Iterator;
import java.util.Map;

import javax.xml.transform.Transformer;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;

import org.kabeja.xml.AbstractSAXFilter;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;


/**
 * @author <a href="mailto:simon.mieth@gmx.de">Simon Mieth</a>
 *
 */
public class SAXXSLTFilter extends AbstractSAXFilter {
    public static final String PROPERTY_XSLTSTYLESHEET = "stylesheet";
    protected ContentHandler handler;
    protected String xsltSource;

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.ContentHandler#startDocument()
     */
    public void startDocument() throws SAXException {
        if (this.properties.containsKey(PROPERTY_XSLTSTYLESHEET)) {
            try {
                SAXTransformerFactory factory = (SAXTransformerFactory) SAXTransformerFactory.newInstance();

                FileReader reader = new FileReader((String) this.properties.get(
                            PROPERTY_XSLTSTYLESHEET));

                SAXSource src = new SAXSource(new InputSource(reader));

                TransformerHandler f = factory.newTransformerHandler(src);
                setParameters(f);

                // put the the transformer in the chain
                f.setResult(new SAXResult(this.handler));
                super.setContentHandler(f);
            } catch (Exception e) {
                throw new SAXException(e);
            }
        }

        super.startDocument();
    }

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.XMLReader#setContentHandler(org.xml.sax.ContentHandler)
     */
    public void setContentHandler(ContentHandler handler) {
        this.handler = handler;
        super.setContentHandler(handler);
    }

    protected void setParameters(TransformerHandler h) {
        Transformer tf = h.getTransformer();
        Iterator i = this.properties.keySet().iterator();

        while (i.hasNext()) {
            String name = (String) i.next();

            if (!PROPERTY_XSLTSTYLESHEET.equals(i)) {
                tf.setParameter(name, this.properties.get(name));
            }
        }
    }

    public Map getProperties() {
        return this.properties;
    }
}