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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
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 *
 * 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
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 * accompanied this code).
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package com.sun.tools.jdeps;

import java.io.IOException;
import java.io.PrintWriter;
import java.lang.module.ModuleDescriptor;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static com.sun.tools.jdeps.Analyzer.NOT_FOUND;

Analyze module dependences and any reference to JDK internal APIs.
It can apply transition reduction on the resulting module graph.
The result prints one line per module it depends on
one line per JDK internal API package it references:
    $MODULE[/$PACKAGE]
/**
 * Analyze module dependences and any reference to JDK internal APIs.
 * It can apply transition reduction on the resulting module graph.
 *
 * The result prints one line per module it depends on
 * one line per JDK internal API package it references:
 *     $MODULE[/$PACKAGE]
 *
 */
public class ModuleExportsAnalyzer extends DepsAnalyzer {
    // source archive to its dependences and JDK internal APIs it references
    private final Map<Archive, Map<Archive,Set<String>>> deps = new HashMap<>();
    private final boolean reduced;
    private final PrintWriter writer;
    public ModuleExportsAnalyzer(JdepsConfiguration config,
                                 JdepsFilter filter,
                                 boolean reduced,
                                 PrintWriter writer) {
        super(config, filter, null,
              Analyzer.Type.PACKAGE,
              false /* all classes */);
        this.reduced = reduced;
        this.writer = writer;
    }

    @Override
    public boolean run() throws IOException {
        // analyze dependences
        boolean rc = super.run();

        // A visitor to record the module-level dependences as well as
        // use of JDK internal APIs
        Analyzer.Visitor visitor = (origin, originArchive, target, targetArchive) -> {
            Set<String> jdkInternals =
                deps.computeIfAbsent(originArchive, _k -> new HashMap<>())
                    .computeIfAbsent(targetArchive, _k -> new HashSet<>());

            Module module = targetArchive.getModule();
            if (originArchive.getModule() != module &&
                    module.isJDK() && !module.isExported(target)) {
                // use of JDK internal APIs
                jdkInternals.add(target);
            }
        };

        // visit the dependences
        archives.stream()
            .filter(analyzer::hasDependences)
            .sorted(Comparator.comparing(Archive::getName))
            .forEach(archive -> analyzer.visitDependences(archive, visitor));


        // print the dependences on named modules
        printDependences();

        // print the dependences on unnamed module
        deps.values().stream()
            .flatMap(map -> map.keySet().stream())
            .filter(archive -> !archive.getModule().isNamed())
            .map(archive -> archive != NOT_FOUND
                                ? "unnamed module: " + archive.getPathName()
                                : archive.getPathName())
            .distinct()
            .sorted()
            .forEach(archive -> writer.format("   %s%n", archive));

        return rc;
    }

    private void printDependences() {
        // find use of JDK internals
        Map<Module, Set<String>> jdkinternals = new HashMap<>();
        dependenceStream()
            .flatMap(map -> map.entrySet().stream())
            .filter(e -> e.getValue().size() > 0)
            .forEach(e -> jdkinternals.computeIfAbsent(e.getKey().getModule(),
                                                       _k -> new HashSet<>())
                                      .addAll(e.getValue()));


        // build module graph
        ModuleGraphBuilder builder = new ModuleGraphBuilder(configuration);
        Module root = new RootModule("root");
        builder.addModule(root);
        // find named module dependences
        dependenceStream()
            .flatMap(map -> map.keySet().stream())
            .filter(m -> m.getModule().isNamed()
                            && !configuration.rootModules().contains(m))
            .map(Archive::getModule)
            .forEach(m -> builder.addEdge(root, m));

        // module dependences
        Set<Module> modules = builder.build().adjacentNodes(root);

        // if reduced is set, apply transition reduction
        Set<Module> reducedSet;
        if (reduced) {
            Set<Module> nodes = builder.reduced().adjacentNodes(root);
            if (nodes.size() == 1) {
                // java.base only
                reducedSet = nodes;
            } else {
                // java.base is mandated and can be excluded from the reduced graph
                reducedSet = nodes.stream()
                    .filter(m -> !"java.base".equals(m.name()) ||
                                    jdkinternals.containsKey("java.base"))
                    .collect(Collectors.toSet());
            }
        } else {
            reducedSet = modules;
        }

        modules.stream()
               .sorted(Comparator.comparing(Module::name))
               .forEach(m -> {
                    if (jdkinternals.containsKey(m)) {
                        jdkinternals.get(m).stream()
                            .sorted()
                            .forEach(pn -> writer.format("   %s/%s%n", m, pn));
                    } else if (reducedSet.contains(m)){
                        // if the transition reduction is applied, show the reduced graph
                        writer.format("   %s%n", m);
                    }
            });
    }

    /*
     * Returns a stream of dependence map from an Archive to the set of JDK
     * internal APIs being used.
     */
    private Stream<Map<Archive, Set<String>>> dependenceStream() {
        return deps.keySet().stream()
                   .filter(source -> !source.getModule().isNamed()
                            || configuration.rootModules().contains(source))
                   .map(deps::get);
    }

    private class RootModule extends Module {
        final ModuleDescriptor descriptor;
        RootModule(String name) {
            super(name);

            ModuleDescriptor.Builder builder = ModuleDescriptor.newModule(name);
            this.descriptor = builder.build();
        }

        @Override
        public ModuleDescriptor descriptor() {
            return descriptor;
        }
    }

}