/*

 * Copyright (c) 2015, 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.

 *

 * 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.

 */

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleFinder;

import java.lang.module.ModuleReader;

import java.lang.module.ModuleReference;

import java.net.URI;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Objects;

import java.util.Optional;

import java.util.Set;

import java.util.function.Supplier;

/**

 * This class consists exclusively of static utility methods that are useful

 * for creating tests for modules.

 */

public final class ModuleUtils {

    private ModuleUtils() { }

    /**

     * Returns a ModuleFinder that finds modules with the given module

     * descriptors.

     */

    static ModuleFinder finderOf(ModuleDescriptor... descriptors) {

        // Create a ModuleReference for each module

        Map<String, ModuleReference> namesToReference = new HashMap<>();

        for (ModuleDescriptor descriptor : descriptors) {

            String name = descriptor.name();

            URI uri = URI.create("module:/" + name);

            Supplier<ModuleReader> supplier = () -> {

                throw new UnsupportedOperationException();

            };

            ModuleReference mref = new ModuleReference(descriptor, uri, supplier);

            namesToReference.put(name, mref);

        }

        return new ModuleFinder() {

            @Override

            public Optional<ModuleReference> find(String name) {

                Objects.requireNonNull(name);

                return Optional.ofNullable(namesToReference.get(name));

            }

            @Override

            public Set<ModuleReference> findAll() {

                return new HashSet<>(namesToReference.values());

            }

        };

    }

}