/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 2 of the License.

 *

 * This program 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 for more details.

 *

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

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.vm4brwsr;

import java.io.IOException;

import java.io.InputStream;

import java.net.URL;

import java.util.Enumeration;

/** Implementation of Resources that delegates to some class loader.

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

final class LdrRsrcs implements Bck2Brwsr.Resources {

    private final ClassLoader loader;

    LdrRsrcs(ClassLoader loader) {

        this.loader = loader;

    }

    @Override

    public InputStream get(String name) throws IOException {

        return findSource(name).openStream();

    }

    @Override

    public String getModule(String name) throws IOException {

        final URL url = findSource(name);

        if (!"jar".equalsIgnoreCase(url.getProtocol())) {

            return null;

        }

        final String fullPathString = url.getPath();

        final int sepIndex = fullPathString.indexOf('!');

        final String jarPathString =

                (sepIndex != -1) ? fullPathString.substring(0, sepIndex)

                                 : fullPathString;

        if (!jarPathString.endsWith(".jar")) {

            return null;

        }

        String moduleName =

                jarPathString.substring(

                                  jarPathString.lastIndexOf('/') + 1,

                                  jarPathString.length() - 4);

        if (moduleName.endsWith("-SNAPSHOT")) {

            moduleName = moduleName.substring(

                                        0, moduleName.length() - 9);

        }

        final int dashIndex = moduleName.lastIndexOf('-');

        if (dashIndex != -1) {

            moduleName = moduleName.substring(0, dashIndex);

        }

        return moduleName;

    }

    private URL findSource(String name) throws IOException {

        Enumeration<URL> en = loader.getResources(name);

        URL u = null;

        while (en.hasMoreElements()) {

            u = en.nextElement();

        }

        if (u == null) {

            throw new IOException("Can't find " + name);

        }

        return u;

    }

}