/*

 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.nashorn.internal.runtime;

import java.io.File;

import java.io.IOException;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLClassLoader;

import java.security.SecureClassLoader;

import jdk.nashorn.tools.Shell;

/**

 * Superclass for Nashorn class loader classes. This stores Context

 * instance as an instance field. The current context can be

 * efficiently accessed from a given Class via it's ClassLoader.

 *

 */

abstract class NashornLoader extends SecureClassLoader {

    private final Context context;

    final Context getContext() {

        return context;

    }

    NashornLoader(final ClassLoader parent, final Context context) {

        super(parent);

        this.context = context;

    }

    /**

     * Called by subclass after package access check is done

     * @param name name of the class to be loaded

     * @param resolve whether the class should be resolved or not

     * @return Class object

     * @throws ClassNotFoundException if class cannot be loaded

     */

    protected final Class<?> loadClassTrusted(final String name, final boolean resolve) throws ClassNotFoundException {

        return super.loadClass(name, resolve);

    }

    protected static void checkPackageAccess(final String name) {

        final int i = name.lastIndexOf('.');

        if (i != -1) {

            final SecurityManager sm = System.getSecurityManager();

            if (sm != null) {

            }

        }

    }

    /**

     * Create a secure URL class loader for the given classpath

     * @param classPath classpath for the loader to search from

     * @return the class loader

     */

    static ClassLoader createClassLoader(final String classPath) {

        final ClassLoader parent = Shell.class.getClassLoader();

        final URL[] urls = pathToURLs(classPath);

        return URLClassLoader.newInstance(urls, parent);

    }

    /*

     * Utility method for converting a search path string to an array

     * of directory and JAR file URLs.

     *

     * @param path the search path string

     * @return the resulting array of directory and JAR file URLs

     */

    private static URL[] pathToURLs(final String path) {

        final String[] components = path.split(File.pathSeparator);

        URL[] urls = new URL[components.length];

        int count = 0;

        while(count < components.length) {

            final URL url = fileToURL(new File(components[count]));

            if (url != null) {

                urls[count++] = url;

            }

        }

        if (urls.length != count) {

            final URL[] tmp = new URL[count];

            System.arraycopy(urls, 0, tmp, 0, count);

            urls = tmp;

        }

        return urls;

    }

    /*

     * Returns the directory or JAR file URL corresponding to the specified

     * local file name.

     *

     * @param file the File object

     * @return the resulting directory or JAR file URL, or null if unknown

     */

    private static URL fileToURL(final File file) {

        String name;

        try {

            name = file.getCanonicalPath();

        } catch (final IOException e) {

            name = file.getAbsolutePath();

        }

        name = name.replace(File.separatorChar, '/');

        if (!name.startsWith("/")) {

            name = "/" + name;

        }

        // If the file does not exist, then assume that it's a directory

        if (!file.isFile()) {

            name = name + "/";

        }

        try {

            return new URL("file", "", name);

        } catch (final MalformedURLException e) {

            throw new IllegalArgumentException("file");

        }

    }

}