/*

 * Copyright (c) 2016, 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 java.lang;

import java.lang.module.Configuration;

import java.lang.module.ModuleReference;

import java.net.URI;

/**

 * A NamedPackage represents a package by name in a specific module.

 *

 * A class loader will automatically create NamedPackage for each

 * package when a class is defined.  Package object is lazily

 * defined until Class::getPackage, Package::getPackage(s), or

 * ClassLoader::getDefinedPackage(s) method is called.

 *

 * NamedPackage allows ClassLoader to keep track of the runtime

 * packages with minimal footprint and avoid constructing Package

 * object.

 */

class NamedPackage {

    private final String name;

    private final Module module;

    NamedPackage(String pn, Module module) {

        if (pn.isEmpty() && module.isNamed()) {

            throw new InternalError("unnamed package in  " + module);

        }

        this.name = pn.intern();

        this.module = module;

    }

    /**

     * Returns the name of this package.

     */

    String packageName() {

        return name;

    }

    /**

     * Returns the module of this named package.

     */

    Module module() {

        return module;

    }

    /**

     * Returns the location of the module if this named package is in

     * a named module; otherwise, returns null.

     */

    URI location() {

        if (module.isNamed() && module.getLayer() != null) {

            Configuration cf = module.getLayer().configuration();

            ModuleReference mref

                = cf.findModule(module.getName()).get().reference();

            return mref.location().orElse(null);

        }

        return null;

    }

    /**

     * Creates a Package object of the given name and module.

     */

    static Package toPackage(String name, Module module) {

        return new Package(name, module);

    }

}