/***** BEGIN LICENSE BLOCK *****
 * Version: CPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Common Public
 * License Version 1.0 (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.eclipse.org/legal/cpl-v10.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * Copyright (C) 2005 Charles O Nutter <headius@headius.com>
 * Copyright (C) 2005 Thomas E. Enebo <enebo@acm.org>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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package org.jruby.runtime.load;

import java.io.BufferedInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.jar.Manifest;

import org.jruby.Ruby;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.load.LoadServiceResource;

/**
 * Loading of Ruby scripts packaged in Jar files.
 *
 * Usually the Ruby scripts are accompanied by Java class files in the Jar.
 *
 */
public class JarredScript implements Library {
    private final LoadServiceResource resource;

    public JarredScript(LoadServiceResource resource) {
        this.resource = resource;
    }

    public LoadServiceResource getResource() {
        return this.resource;
    }

    public void load(Ruby runtime) {
        URL jarFile = resource.getURL();

        // Make Java class files in the jar reachable from Ruby
        runtime.getJavaSupport().addToClasspath(jarFile);

        try {
            JarInputStream in = new JarInputStream(new BufferedInputStream(jarFile.openStream()));

            Manifest mf = in.getManifest();
            if (mf != null) {
                String rubyInit = mf.getMainAttributes().getValue("Ruby-Init");
                if (rubyInit != null) {
                    JarEntry entry = in.getNextJarEntry();
                    while (entry != null && !entry.getName().equals(rubyInit)) {
                        entry = in.getNextJarEntry();
                    }
                    if (entry != null) {
                        IRubyObject old = runtime.getGlobalVariables().isDefined("$JAR_URL") ? runtime.getGlobalVariables().get("$JAR_URL") : runtime.getNil();
                        try {
                            runtime.getGlobalVariables().set("$JAR_URL", runtime.newString("jar:" + jarFile + "!/"));
                            runtime.loadScript("init", new InputStreamReader(in));
                        } finally {
                            runtime.getGlobalVariables().set("$JAR_URL", old);
                        }
                    }
                }
            }
            in.close();
        } catch (FileNotFoundException e) {
            throw runtime.newIOErrorFromException(e);
        } catch (IOException e) {
            throw runtime.newIOErrorFromException(e);
        }
    }
}