/*

 * 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

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 */

package jdk.tools.jlink.internal;

import java.lang.module.Configuration;

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleFinder;

import java.lang.module.ModuleReader;

import java.lang.module.ModuleReference;

import java.io.IOException;

import java.io.UncheckedIOException;

import java.nio.ByteBuffer;

import java.util.Collection;

import java.util.HashSet;

import java.util.Map;

import java.util.Optional;

import java.util.Set;

import java.util.stream.Collectors;

import jdk.tools.jlink.plugin.PluginException;

import jdk.tools.jlink.plugin.ResourcePool;

import jdk.tools.jlink.plugin.ResourcePoolEntry;

import jdk.tools.jlink.plugin.ResourcePoolModule;

final class ResourcePoolConfiguration {

    private ResourcePoolConfiguration() {}

    private static ModuleDescriptor descriptorOf(ResourcePoolModule mod) {

        ModuleDescriptor md = mod.descriptor();

        // drop hashes

        ModuleDescriptor.Builder builder = ModuleDescriptor.newModule(md.name());

        md.requires().stream()

          .forEach(builder::requires);

        md.exports().stream()

          .forEach(builder::exports);

        md.opens().stream()

          .forEach(builder::opens);

        md.uses().stream()

          .forEach(builder::uses);

        md.provides().stream()

          .forEach(builder::provides);

        builder.packages(md.packages());

        md.version().ifPresent(builder::version);

        md.mainClass().ifPresent(builder::mainClass);

        return builder.build();

    }

    private static ModuleReference moduleReference(ModuleDescriptor desc) {

        return new ModuleReference(desc, null) {

            @Override

            public ModuleReader open() {

                throw new UnsupportedOperationException();

            }

        };

    }

    private static Map<String, ModuleReference> allModRefs(ResourcePool pool) {

        return pool.moduleView().modules().

            collect(Collectors.toMap(ResourcePoolModule::name,

                m -> moduleReference(descriptorOf(m))));

    }

    private static void checkPackages(ResourcePool pool) {

        // check that each resource pool module's packages()

        // returns a set that is consistent with the module

        // descriptor of that module.

        pool.moduleView().modules().forEach(m -> {

            ModuleDescriptor desc = m.descriptor();

            if (!desc.packages().equals(m.packages())) {

                throw new RuntimeException("Module " + m.name() +

                   "'s descriptor indicates the set of packages is : " +

                   desc.packages() + ", but module contains packages: " +

                   m.packages());

            }

        });

    }

    static Configuration validate(ResourcePool pool) {

        checkPackages(pool);

        final Map<String, ModuleReference> nameToModRef = allModRefs(pool);

        final Set<ModuleReference> allRefs = new HashSet<>(nameToModRef.values());

        final ModuleFinder finder = new ModuleFinder() {

            @Override

            public Optional<ModuleReference> find(String name) {

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

            }

            @Override

            public Set<ModuleReference> findAll() {

                return allRefs;

            }

        };

        return Configuration.empty().resolve(

            finder, ModuleFinder.of(), nameToModRef.keySet());

    }

}