// $Id: DataStreamHandler.java,v 1.9 2009-05-01 13:25:59 jim Exp $

/*
This code is released as public domain: you are free to use it in any way that you want. 
*/
package org.faceless.util;

import java.io.*;
import java.net.*;
import org.faceless.util.Base64InputStream;
import org.faceless.util.Base64OutputStream;

/**
 * A URLStreamHandler for the <a href="http://www.ietf.org/rfc/rfc2397.txt">data</a> URL
 * scheme. Factory is combined into this class for simplicity.
 *
 * Can't rely on this unfortunately, as at least WebLogic uses it's own streamhandlerfactory
 */
public class DataStreamHandler extends URLStreamHandler
{
    public  int getDefaultPort() {
        return -1;
    }
    
    public  InetAddress getHostAddress(URL url) {
        return null;
    }
    
    public URLConnection openConnection(final URL url) {
        return new URLConnection(url) {
            public void connect() {
            }

            public InputStream getInputStream() {
                String path = this.url.getPath();
                int i = path.indexOf(",");
                String data = path.substring(i+1);
                boolean base64 = path.substring(0, i).endsWith(";base64");
                try {
                    if (base64) {
                        return new Base64InputStream(new ByteArrayInputStream(data.getBytes("US-ASCII")));
                    } else {
                        return new FilterInputStream(new ByteArrayInputStream(data.getBytes("US-ASCII"))) {
                            public int read() throws IOException {
                                int c = super.read();
                                if (c=='%') {
                                    c = (Integer.parseInt(""+((char)super.read()), 16)<<4) + Integer.parseInt(""+((char)super.read()), 16);     // Character.toString() is a 1.4 feature, can't use
                                }
                                return c;
                            }
                        };
                    }
                } catch (IOException e) {
                    throw new Error("No US-ASCII encoding");
                }
            }

            public String getContentType() {
                String type = this.url.getPath();
                type = type.substring(0, type.indexOf(","));
                if (type.endsWith(";base64")) {
                    type = type.substring(0, type.length()-7);
                }
                return type.length()==0 ? "text/plain;charset=US-ASCII" : type;
            }
        };
    }

    /**
     * Return a factory creating objects of this type
     */
    public static final URLStreamHandlerFactory createFactory() {
        return new URLStreamHandlerFactory() {
            public URLStreamHandler createURLStreamHandler(String protocol) {
                return protocol.equalsIgnoreCase("data") ? new DataStreamHandler() : null;
            }
        };
    }

    /**
     * Create a data URL for the specified object
     * @param data the data to embed in the URL
     * @param mimetype the MIME-type of the data
     * @return a "data:" URL 
     */
    public static final String encode(byte[] data, String mimetype) {
        try {
            final StringBuffer sb = new StringBuffer((data.length/3*4)+mimetype.length()+8);
            sb.append("data:");
            sb.append(mimetype);
            sb.append(";base64,");
            OutputStream out = new OutputStream() {
                public void write(int c) { sb.append((char)(c&0xFF)); }
            };
            Base64OutputStream fout = new Base64OutputStream(out, false);
            fout.write(data);
            fout.close();
            return sb.toString();
        } catch (IOException e) {
            RuntimeException e2 = new RuntimeException(e.getMessage());
            try {
                e2.initCause(e);
            } catch (Throwable e3) { }
            throw e2;
        }
    }

    /*
    public static void main(String[] args) throws Exception {
        URL.setURLStreamHandlerFactory(createFactory());

        // String urlstring = encode("This is a test".getBytes("ISO-8859-1"), "text/plain");
        String urlstring = "data:image/png;base64,"+
            "iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAABGdBTUEAALGP"+
            "C/xhBQAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9YGARc5KB0XV+IA"+
            "AAAddEVYdENvbW1lbnQAQ3JlYXRlZCB3aXRoIFRoZSBHSU1Q72QlbgAAAF1J"+
            "REFUGNO9zL0NglAAxPEfdLTs4BZM4DIO4C7OwQg2JoQ9LE1exdlYvBBeZ7jq"+
            "ch9//q1uH4TLzw4d6+ErXMMcXuHWxId3KOETnnXXV6MJpcq2MLaI97CER3N0"+
            "vr4MkhoXe0rZigAAAABJRU5ErkJggg==";

        URLConnection con = new URL(urlstring).openConnection();
        System.err.println("Content-type: "+con.getContentType());
        InputStream in = con.getInputStream();
        OutputStream out = System.out;

        int c;
        while ((c=in.read())>=0) {
            out.write(c);
        }
        out.flush();
    }
    */
}