/*******************************************************************************
 * 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.batik.tools;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import org.apache.batik.util.Base64EncoderStream;
import org.kabeja.xml.SAXFilter;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import org.xml.sax.helpers.XMLFilterImpl;


/**
 * @author <a href="mailto:simon.mieth@gmx.de">Simon Mieth</a>
 *
 */
public class ImageBase64Encoder extends XMLFilterImpl implements SAXFilter {
    public static final String ELEMENT_IMAGE = "image";
    public static final String XLINK_NAMESPACE = "http://www.w3.org/1999/xlink";
    public static final String XLINK_ATTRIBUTE_HREF = "href";
    protected Map properties = new HashMap();

    /*
     * (non-Javadoc)
     *
     * @see org.kabeja.xml.SAXFilter#setProperties(java.util.Map)
     */
    public void setProperties(Map properties) {
    }

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.ContentHandler#startElement(java.lang.String,
     *      java.lang.String, java.lang.String, org.xml.sax.Attributes)
     */
    public void startElement(String uri, String localName, String qName,
        Attributes atts) throws SAXException {
        if (ELEMENT_IMAGE.equals(localName)) {
            boolean resolved = false;
            AttributesImpl attr = new AttributesImpl(atts);

            for (int i = 0; i < attr.getLength(); i++) {
                if (XLINK_ATTRIBUTE_HREF.equals(attr.getLocalName(i))) {
                    String file = attr.getValue(i);
                    String base = encodeBase64(file);

                    if (base != null) {
                        attr.setValue(i, base);
                        resolved = true;
                    }
                }
            }

            if (resolved) {
                super.startElement(uri, localName, qName, attr);
            }
        } else {
            super.startElement(uri, localName, qName, atts);
        }
    }

    protected String encodeBase64(String file) {
        try {
            URL url = new URL(file);

            ByteArrayOutputStream bos = new ByteArrayOutputStream(32000);
            bos.write("data:;base64,".getBytes());

            Base64EncoderStream base = new Base64EncoderStream(bos);

            BufferedInputStream in = new BufferedInputStream(url.openStream());
            int l = -1;
            byte[] b = new byte[1024];

            while ((l = in.read(b)) > -1) {
                base.write(b, 0, l);
            }

            in.close();
            base.flush();
            base.close();

            return new String(bos.toByteArray());
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        return "";
    }

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