/*
 * 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.
 */

package org.apache.axis2.classloader;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * @version $Rev: 476049 $ $Date: 2006-11-16 23:35:17 -0500 (Thu, 16 Nov 2006) $
 */
public class JarFileUrlStreamHandler extends URLStreamHandler {
    public static URL createUrl(JarFile jarFile, JarEntry jarEntry) throws MalformedURLException {
        return createUrl(jarFile, jarEntry, new File(jarFile.getName()).toURL());
    }

    public static URL createUrl(JarFile jarFile, JarEntry jarEntry, URL codeSource) throws MalformedURLException {
        JarFileUrlStreamHandler handler = new JarFileUrlStreamHandler(jarFile, jarEntry);
        URL url = new URL("jar", "", -1, codeSource + "!/" + jarEntry.getName(), handler);
        handler.setExpectedUrl(url);
        return url;
    }

    private URL expectedUrl;
    private JarFile jarFile = null;
    private JarEntry jarEntry = null;

    public JarFileUrlStreamHandler() {
    }

    public JarFileUrlStreamHandler(JarFile jarFile, JarEntry jarEntry) {
        if (jarFile == null) throw new NullPointerException("jarFile is null");
        if (jarEntry == null) throw new NullPointerException("jarEntry is null");

        this.jarFile = jarFile;
        this.jarEntry = jarEntry;
    }

    public void setExpectedUrl(URL expectedUrl) {
        if (expectedUrl == null) throw new NullPointerException("expectedUrl is null");
        this.expectedUrl = expectedUrl;
    }

    public URLConnection openConnection(URL url) throws IOException {

        if (expectedUrl == null || !expectedUrl.equals(url)) {
            // the new url is supposed to be within our context, so it must have a jar protocol
            if (!url.getProtocol().equals("jar")) {
                throw new IllegalArgumentException("Unsupported protocol " + url.getProtocol());
            }

            // split the path at "!/" into the file part and entry part
            String path = url.getPath();
            String[] chunks = path.split("!/", 2);

            // if we only got only one chunk, it didn't contain the required "!/" delimiter
            if (chunks.length == 1) {
                throw new MalformedURLException("Url does not contain a '!' character: " + url);
            }

            String file = chunks[0];
            String entryPath = chunks[1];

            // this handler only supports jars on the local file system
            if (!file.startsWith("file:")) {
                // let the system handler deal with this
                return new URL(url.toExternalForm()).openConnection();
            }
            file = file.substring("file:".length());

            File f = new File(file);
            if (f.exists()) {
                jarFile = new JarFile(f);
            }

            if (jarFile == null) {
                throw new FileNotFoundException("Cannot find JarFile: " + file);
            }

            // get the entry
            jarEntry = jarFile.getJarEntry(entryPath);
            if (jarEntry == null) {
                throw new FileNotFoundException("Entry not found: " + url);
            }
            expectedUrl = url;
        }

        return new JarFileUrlConnection(url, jarFile, jarEntry);
    }
}