/*

 * Copyright (c) 2015, 2019, 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.

 */

import java.io.File;

import java.io.IOException;

import java.io.StringReader;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.nio.file.Files;

import java.nio.file.Path;

import java.text.MessageFormat;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.EnumSet;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.LinkedHashMap;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Map;

import java.util.Properties;

import java.util.ResourceBundle;

import java.util.Set;

import java.util.Optional;

import java.util.Arrays;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import java.util.regex.Matcher;

import java.util.spi.ToolProvider;

import java.util.jar.JarFile;

import java.lang.module.Configuration;

import java.lang.module.ResolvedModule;

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleFinder;

import java.lang.module.ModuleReference;

import jdk.internal.module.ModulePath;

final class JLinkBundlerHelper {

    private static final ResourceBundle I18N = ResourceBundle.getBundle(

    static final ToolProvider JLINK_TOOL =

            ToolProvider.findFirst("jlink").orElseThrow();

    static File getMainJar(Map<String, ? super Object> params) {

        File result = null;

        RelativeFileSet fileset =

                StandardBundlerParam.MAIN_JAR.fetchFrom(params);

        if (fileset != null) {

            String filename = fileset.getIncludedFiles().iterator().next();

            result = fileset.getBaseDirectory().toPath().

                    resolve(filename).toFile();

            if (result == null || !result.exists()) {

                String srcdir =

                    StandardBundlerParam.SOURCE_DIR.fetchFrom(params);

                if (srcdir != null) {

                    result = new File(srcdir + File.separator + filename);

                }

            }

        }

        return result;

    }

    static String getMainClassFromModule(Map<String, ? super Object> params) {

        String mainModule = StandardBundlerParam.MODULE.fetchFrom(params);

        if (mainModule != null)  {

            int index = mainModule.indexOf("/");

            if (index > 0) {

                return mainModule.substring(index + 1);

            } else {

                ModuleDescriptor descriptor =

                        JLinkBundlerHelper.getMainModuleDescription(params);

                if (descriptor != null) {

                    Optional<String> mainClass = descriptor.mainClass();

                    if (mainClass.isPresent()) {

                        Log.verbose(MessageFormat.format(I18N.getString(

                                    "message.module-class"),

                                    mainClass.get(),

                                    JLinkBundlerHelper.getMainModule(params)));

                        return mainClass.get();

                    }

                }

            }

        }

        return null;

    }

    static String getMainModule(Map<String, ? super Object> params) {

        String result = null;

        String mainModule = StandardBundlerParam.MODULE.fetchFrom(params);

        if (mainModule != null) {

            int index = mainModule.indexOf("/");

            if (index > 0) {

                result = mainModule.substring(0, index);

            } else {

                result = mainModule;

            }

        }

        return result;

    }

    static void execute(Map<String, ? super Object> params,

            AbstractAppImageBuilder imageBuilder)

            throws IOException, Exception {

        List<Path> modulePath =

                StandardBundlerParam.MODULE_PATH.fetchFrom(params);

        Set<String> addModules =

                StandardBundlerParam.ADD_MODULES.fetchFrom(params);

        Set<String> limitModules =

                StandardBundlerParam.LIMIT_MODULES.fetchFrom(params);

        Path outputDir = imageBuilder.getRuntimeRoot();

        File mainJar = getMainJar(params);

        ModFile.ModType mainJarType = ModFile.ModType.Unknown;

        if (mainJar != null) {

            mainJarType = new ModFile(mainJar).getModType();

        } else if (StandardBundlerParam.MODULE.fetchFrom(params) == null) {

            // user specified only main class, all jars will be on the classpath

            mainJarType = ModFile.ModType.UnnamedJar;

        }

        boolean bindServices =

                StandardBundlerParam.BIND_SERVICES.fetchFrom(params);

        // Modules

        String mainModule = getMainModule(params);

        if (mainModule == null) {

            if (mainJarType == ModFile.ModType.UnnamedJar) {

                if (addModules.isEmpty()) {

                    // The default for an unnamed jar is ALL_DEFAULT

                    addModules.add(ModuleHelper.ALL_DEFAULT);

                }

            } else if (mainJarType == ModFile.ModType.Unknown ||

                    mainJarType == ModFile.ModType.ModularJar) {

                addModules.add(ModuleHelper.ALL_DEFAULT);

            }

        }

        Set<String> modules = new ModuleHelper(

                modulePath, addModules, limitModules).modules();

        if (mainModule != null) {

            modules.add(mainModule);

        }

        runJLink(outputDir, modulePath, modules, limitModules,

                new HashMap<String,String>(), bindServices);

        imageBuilder.prepareApplicationFiles(params);

    }

    // Returns the path to the JDK modules in the user defined module path.

    static Path findPathOfModule( List<Path> modulePath, String moduleName) {

        for (Path path : modulePath) {

            Path moduleNamePath = path.resolve(moduleName);

            if (Files.exists(moduleNamePath)) {

                return path;

            }

        }

        return null;

    }

    static ModuleDescriptor getMainModuleDescription(Map<String, ? super Object> params) {

        boolean hasModule = params.containsKey(StandardBundlerParam.MODULE.getID());

        if (hasModule) {

            List<Path> modulePath = StandardBundlerParam.MODULE_PATH.fetchFrom(params);

            if (!modulePath.isEmpty()) {

                ModuleFinder finder = ModuleFinder.of(modulePath.toArray(new Path[0]));

                String mainModule = JLinkBundlerHelper.getMainModule(params);

                Optional<ModuleReference> omref = finder.find(mainModule);

                if (omref.isPresent()) {

                    return omref.get().descriptor();

                }

            }

        }

        return null;

    }

    /*

     * Returns the set of modules that would be visible by default for

     * a non-modular-aware application consisting of the given elements.

     */

    private static Set<String> getDefaultModules(

            Collection<Path> paths, Collection<String> addModules) {

        // the modules in the run-time image that export an API

        Stream<String> systemRoots = ModuleFinder.ofSystem().findAll().stream()

                .map(ModuleReference::descriptor)

                .filter(JLinkBundlerHelper::exportsAPI)

                .map(ModuleDescriptor::name);

        Set<String> roots = Stream.concat(systemRoots,

                 addModules.stream()).collect(Collectors.toSet());

        ModuleFinder finder = createModuleFinder(paths);

        return Configuration.empty()

                .resolveAndBind(finder, ModuleFinder.of(), roots)

                .modules()

                .stream()

                .map(ResolvedModule::name)

                .collect(Collectors.toSet());

    }

    /*

     * Returns true if the given module exports an API to all module.

     */

    private static boolean exportsAPI(ModuleDescriptor descriptor) {

        return descriptor.exports()

                .stream()

                .anyMatch(e -> !e.isQualified());

    }

    private static ModuleFinder createModuleFinder(Collection<Path> modulePath) {

        return ModuleFinder.compose(

                ModulePath.of(JarFile.runtimeVersion(), true,

                        modulePath.toArray(Path[]::new)),

                ModuleFinder.ofSystem());

    }

    private static class ModuleHelper {

        // The token for "all modules on the module path".

        private static final String ALL_MODULE_PATH = "ALL-MODULE-PATH";

        // The token for "all valid runtime modules".

        static final String ALL_DEFAULT = "ALL-DEFAULT";

        private final Set<String> modules = new HashSet<>();

        ModuleHelper(List<Path> paths, Set<String> addModules,

                Set<String> limitModules) {

            boolean addAllModulePath = false;

            boolean addDefaultMods = false;

            for (Iterator<String> iterator = addModules.iterator();

                    iterator.hasNext();) {

                String module = iterator.next();

                switch (module) {

                    case ALL_MODULE_PATH:

                        iterator.remove();

                        addAllModulePath = true;

                        break;

                    case ALL_DEFAULT:

                        iterator.remove();

                        addDefaultMods = true;

                        break;

                    default:

                        this.modules.add(module);

                }

            }

            if (addAllModulePath) {

                this.modules.addAll(getModuleNamesFromPath(paths));

            } else if (addDefaultMods) {

                this.modules.addAll(getDefaultModules(

                        paths, addModules));

            }

        }

        Set<String> modules() {

            return modules;

        }

        private static Set<String> getModuleNamesFromPath(List<Path> paths) {

            return createModuleFinder(paths)

                    .findAll()

                    .stream()

                    .map(ModuleReference::descriptor)

                    .map(ModuleDescriptor::name)

                    .collect(Collectors.toSet());

        }

    }

    private static void runJLink(Path output, List<Path> modulePath,

            Set<String> modules, Set<String> limitModules,

            HashMap<String, String> user, boolean bindServices)

            throws PackagerException {

        // This is just to ensure jlink is given a non-existant directory

        // The passed in output path should be non-existant or empty directory

        try {

            IOUtils.deleteRecursive(output.toFile());

        } catch (IOException ioe) {

            throw new PackagerException(ioe);

        }

        ArrayList<String> args = new ArrayList<String>();

        args.add("--output");

        args.add(output.toString());

        if (modulePath != null && !modulePath.isEmpty()) {

            args.add("--module-path");

            args.add(getPathList(modulePath));

        }

        if (modules != null && !modules.isEmpty()) {

            args.add("--add-modules");

            args.add(getStringList(modules));

        }

        if (limitModules != null && !limitModules.isEmpty()) {

            args.add("--limit-modules");

            args.add(getStringList(limitModules));

        }

        if (user != null && !user.isEmpty()) {

            for (Map.Entry<String, String> entry : user.entrySet()) {

                args.add(entry.getKey());

                args.add(entry.getValue());

            }

        } else {

            args.add("--strip-native-commands");

            args.add("--strip-debug");

            args.add("--no-man-pages");

            args.add("--no-header-files");

            if (bindServices) {

                args.add("--bind-services");

            }

        }

        StringWriter writer = new StringWriter();

        PrintWriter pw = new PrintWriter(writer);

        Log.verbose("jlink arguments: " + args);

        int retVal = JLINK_TOOL.run(pw, pw, args.toArray(new String[0]));

        String jlinkOut = writer.toString();

        if (retVal != 0) {

            throw new PackagerException("error.jlink.failed" , jlinkOut);

        } else if (jlinkOut.length() > 0) {

            Log.verbose("jlink output: " + jlinkOut);

        }

    }

    private static String getPathList(List<Path> pathList) {

        String ret = null;

        for (Path p : pathList) {

            String s =  Matcher.quoteReplacement(p.toString());

            if (ret == null) {

                ret = s;

            } else {

                ret += File.pathSeparator +  s;

            }

        }

        return ret;

    }

    private static String getStringList(Set<String> strings) {

        String ret = null;

        for (String s : strings) {

            if (ret == null) {

                ret = s;

            } else {

                ret += "," + s;

            }

        }

        return (ret == null) ? null : Matcher.quoteReplacement(ret);

    }

}