/*

 * 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.

 */

package tests;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintStream;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.StandardCopyOption;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashSet;

import java.util.List;

import java.util.Objects;

import java.util.Set;

import java.util.jar.JarEntry;

import java.util.jar.JarInputStream;

import java.util.jar.JarOutputStream;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import java.util.zip.ZipEntry;

import javax.tools.JavaCompiler;

import javax.tools.StandardJavaFileManager;

import javax.tools.StandardLocation;

import javax.tools.ToolProvider;

/**

 *

 * A generator for jmods, jars and images.

 */

public class JImageGenerator {

    public static final String LOAD_ALL_CLASSES_TEMPLATE = "package PACKAGE;\n"

            + "\n"

            + "import java.net.URI;\n"

            + "import java.nio.file.FileSystems;\n"

            + "import java.nio.file.Files;\n"

            + "import java.nio.file.Path;\n"

            + "import java.util.function.Function;\n"

            + "\n"

            + "public class CLASS {\n"

            + "    private static long total_time;\n"

            + "    private static long num_classes;\n"

            + "    public static void main(String[] args) throws Exception {\n"

            + "        Function<Path, String> formatter = (path) -> {\n"

            + "            String clazz = path.toString().substring(\"modules/\".length()+1, path.toString().lastIndexOf(\".\"));\n"

            + "            clazz = clazz.substring(clazz.indexOf(\"/\") + 1);\n"

            + "            return clazz.replaceAll(\"/\", \"\\\\.\");\n"

            + "        };\n"

            + "        Files.walk(FileSystems.getFileSystem(URI.create(\"jrt:/\")).getPath(\"/modules/\")).\n"

            + "                filter((p) -> {\n"

            + "                    return Files.isRegularFile(p) && p.toString().endsWith(\".class\")\n"

            + "                    && !p.toString().endsWith(\"module-info.class\");\n"

            + "                }).\n"

            + "                map(formatter).forEach((clazz) -> {\n"

            + "                    try {\n"

            + "                        long t = System.currentTimeMillis();\n"

            + "                        Class.forName(clazz, false, Thread.currentThread().getContextClassLoader());\n"

            + "                        total_time+= System.currentTimeMillis()-t;\n"

            + "                        num_classes+=1;\n"

            + "                    } catch (IllegalAccessError ex) {\n"

            + "                        // Security exceptions can occur, this is not what we are testing\n"

            + "                        System.err.println(\"Access error, OK \" + clazz);\n"

            + "                    } catch (Exception ex) {\n"

            + "                        System.err.println(\"ERROR \" + clazz);\n"

            + "                        throw new RuntimeException(ex);\n"

            + "                    }\n"

            + "                });\n"

            + "    double res = (double) total_time / num_classes;\n"

            + "    // System.out.println(\"Total time \" + total_time + \" num classes \" + num_classes + \" average \" + res);\n"

            + "    }\n"

            + "}\n";

    private static final String OUTPUT_OPTION = "--output";

    private static final String POST_PROCESS_OPTION = "--post-process-path";

    private static final String MAIN_CLASS_OPTION = "--main-class";

    private static final String CLASS_PATH_OPTION = "--class-path";

    private static final String MODULE_PATH_OPTION = "--module-path";

    private static final String ADD_MODULES_OPTION = "--add-modules";

    private static final String LIMIT_MODULES_OPTION = "--limit-modules";

    private static final String PLUGIN_MODULE_PATH = "--plugin-module-path";

    private static final String CMDS_OPTION = "--cmds";

    private static final String CONFIG_OPTION = "--config";

    private static final String HASH_MODULES_OPTION = "--hash-modules";

    private static final String LIBS_OPTION = "--libs";

    private static final String MODULE_VERSION_OPTION = "--module-version";

    private JImageGenerator() {}

    private static String optionsPrettyPrint(String... args) {

        return Stream.of(args).collect(Collectors.joining(" "));

    }

    public static File getJModsDir(File jdkHome) {

        File jdkjmods = new File(jdkHome, "jmods");

        if (!jdkjmods.exists()) {

            return null;

        }

        return jdkjmods;

    }

    public static Path addFiles(Path module, InMemoryFile... resources) throws IOException {

        Path tempFile = Files.createTempFile("jlink-test", "");

        try (JarInputStream in = new JarInputStream(Files.newInputStream(module));

             JarOutputStream out = new JarOutputStream(new FileOutputStream(tempFile.toFile()))) {

            ZipEntry entry;

            while ((entry = in.getNextEntry()) != null) {

                String name = entry.getName();

                out.putNextEntry(new ZipEntry(name));

                copy(in, out);

                out.closeEntry();

            }

            for (InMemoryFile r : resources) {

                addFile(r, out);

            }

        }

        Files.move(tempFile, module, StandardCopyOption.REPLACE_EXISTING);

        return module;

    }

    private static void copy(InputStream in, OutputStream out) throws IOException {

        int len;

        byte[] buf = new byte[4096];

        while ((len = in.read(buf)) > 0) {

            out.write(buf, 0, len);

        }

    }

    public static JModTask getJModTask() {

        return new JModTask();

    }

    public static JLinkTask getJLinkTask() {

        return new JLinkTask();

    }

    public static JImageTask getJImageTask() {

        return new JImageTask();

    }

    private static void addFile(InMemoryFile resource, JarOutputStream target) throws IOException {

        String fileName = resource.getPath();

        fileName = fileName.replace("\\", "/");

        String[] ss = fileName.split("/");

        Path p = Paths.get("");

        for (int i = 0; i < ss.length; ++i) {

            if (i < ss.length - 1) {

                if (!ss[i].isEmpty()) {

                    p = p.resolve(ss[i]);

                    JarEntry entry = new JarEntry(p.toString() + "/");

                    target.putNextEntry(entry);

                    target.closeEntry();

                }

            } else {

                p = p.resolve(ss[i]);

                JarEntry entry = new JarEntry(p.toString());

                target.putNextEntry(entry);

                copy(resource.getBytes(), target);

                target.closeEntry();

            }

        }

    }

    public static Path createNewFile(Path root, String pathName, String extension) {

        Path out = root.resolve(pathName + extension);

        int i = 1;

        while (Files.exists(out)) {

            out = root.resolve(pathName + "-" + (++i) + extension);

        }

        return out;

    }

    public static Path generateSources(Path output, String moduleName, List<InMemorySourceFile> sources) throws IOException {

        Path moduleDir = output.resolve(moduleName);

        Files.createDirectory(moduleDir);

        for (InMemorySourceFile source : sources) {

            Path fileDir = moduleDir;

            if (!source.packageName.isEmpty()) {

                String dir = source.packageName.replace('.', File.separatorChar);

                fileDir = moduleDir.resolve(dir);

                Files.createDirectories(fileDir);

            }

            Files.write(fileDir.resolve(source.className + ".java"), source.source.getBytes());

        }

        return moduleDir;

    }

    public static Path generateSourcesFromTemplate(Path output, String moduleName, String... classNames) throws IOException {

        List<InMemorySourceFile> sources = new ArrayList<>();

        for (String className : classNames) {

            String packageName = getPackageName(className);

            String simpleName = getSimpleName(className);

            String content = LOAD_ALL_CLASSES_TEMPLATE

                    .replace("CLASS", simpleName);

            if (packageName.isEmpty()) {

                content = content.replace("package PACKAGE;", packageName);

            } else {

                content = content.replace("PACKAGE", packageName);

            }

            sources.add(new InMemorySourceFile(packageName, simpleName, content));

        }

        return generateSources(output, moduleName, sources);

    }

    public static void generateModuleInfo(Path moduleDir, List<String> packages, String... dependencies) throws IOException {

        StringBuilder moduleInfoBuilder = new StringBuilder();

        Path file = moduleDir.resolve("module-info.java");

        String moduleName = moduleDir.getFileName().toString();

        moduleInfoBuilder.append("module ").append(moduleName).append("{\n");

        for (String dep : dependencies) {

            moduleInfoBuilder.append("requires ").append(dep).append(";\n");

        }

        for (String pkg : packages) {

            if (!pkg.trim().isEmpty()) {

                moduleInfoBuilder.append("exports ").append(pkg).append(";\n");

            }

        }

        moduleInfoBuilder.append("}");

        Files.write(file, moduleInfoBuilder.toString().getBytes());

    }

    public static void compileSuccess(Path source, Path destination, String... options) throws IOException {

        if (!compile(source, destination, options)) {

            throw new AssertionError("Compilation failed.");

        }

    }

    public static boolean compile(Path source, Path destination, String... options) throws IOException {

        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        try (StandardJavaFileManager jfm = compiler.getStandardFileManager(null, null, null)) {

            List<Path> sources

                    = Files.find(source, Integer.MAX_VALUE,

                    (file, attrs) -> file.toString().endsWith(".java"))

                    .collect(Collectors.toList());

            Files.createDirectories(destination);

            jfm.setLocationFromPaths(StandardLocation.CLASS_OUTPUT, Collections.singleton(destination));

            List<String> opts = Arrays.asList(options);

            JavaCompiler.CompilationTask task

                    = compiler.getTask(null, jfm, null, opts, null,

                    jfm.getJavaFileObjectsFromPaths(sources));

            List<String> list = new ArrayList<>(opts);

            list.addAll(sources.stream()

                    .map(Path::toString)

                    .collect(Collectors.toList()));

            System.err.println("javac options: " + optionsPrettyPrint(list.toArray(new String[list.size()])));

            return task.call();

        }

    }

    public static Path createJarFile(Path jarfile, Path dir) throws IOException {

        return createJarFile(jarfile, dir, Paths.get("."));

    }

    public static Path createJarFile(Path jarfile, Path dir, Path file) throws IOException {

        // create the target directory

        Path parent = jarfile.getParent();

        if (parent != null)

            Files.createDirectories(parent);

        List<Path> entries = Files.find(dir.resolve(file), Integer.MAX_VALUE,

                (p, attrs) -> attrs.isRegularFile())

                .map(dir::relativize)

                .collect(Collectors.toList());

        try (OutputStream out = Files.newOutputStream(jarfile);

             JarOutputStream jos = new JarOutputStream(out)) {

            for (Path entry : entries) {

                // map the file path to a name in the JAR file

                Path normalized = entry.normalize();

                String name = normalized

                        .subpath(0, normalized.getNameCount())  // drop root

                        .toString()

                        .replace(File.separatorChar, '/');

                jos.putNextEntry(new JarEntry(name));

                Files.copy(dir.resolve(entry), jos);

            }

        }

        return jarfile;

    }

    public static Set<String> getModuleContent(Path module) {

        Result result = JImageGenerator.getJModTask()

                .jmod(module)

                .list();

        result.assertSuccess();

        return Stream.of(result.getMessage().split("\r?\n"))

                .collect(Collectors.toSet());

    }

    public static void checkModule(Path module, Set<String> expected) throws IOException {

        Set<String> actual = getModuleContent(module);

        if (!Objects.equals(actual, expected)) {

            Set<String> unexpected = new HashSet<>(actual);

            unexpected.removeAll(expected);

            Set<String> notFound = new HashSet<>(expected);

            notFound.removeAll(actual);

            System.err.println("Unexpected files:");

            unexpected.forEach(s -> System.err.println("\t" + s));

            System.err.println("Not found files:");

            notFound.forEach(s -> System.err.println("\t" + s));

            throw new AssertionError("Module check failed.");

        }

    }

    public static class JModTask {

        private final List<Path> classpath = new ArrayList<>();

        private final List<Path> libs = new ArrayList<>();

        private final List<Path> cmds = new ArrayList<>();

        private final List<Path> config = new ArrayList<>();

        private final List<Path> jars = new ArrayList<>();

        private final List<Path> jmods = new ArrayList<>();

        private final List<String> options = new ArrayList<>();

        private Path output;

        private String hashModules;

        private String mainClass;

        private String moduleVersion;

        public JModTask addNativeLibraries(Path cp) {

            this.libs.add(cp);

            return this;

        }

        public JModTask hashModules(String hash) {

            this.hashModules = hash;

            return this;

        }

        public JModTask addCmds(Path cp) {

            this.cmds.add(cp);

            return this;

        }

        public JModTask addClassPath(Path cp) {

            this.classpath.add(cp);

            return this;

        }

        public JModTask addConfig(Path cp) {

            this.config.add(cp);

            return this;

        }

        public JModTask addJars(Path jars) {

            this.jars.add(jars);

            return this;

        }

        public JModTask addJmods(Path jmods) {

            this.jmods.add(jmods);

            return this;

        }

        public JModTask jmod(Path output) {

            this.output = output;

            return this;

        }

        public JModTask moduleVersion(String moduleVersion) {

            this.moduleVersion = moduleVersion;

            return this;

        }

        public JModTask mainClass(String mainClass) {

            this.mainClass = mainClass;

            return this;

        }

        public JModTask option(String o) {

            this.options.add(o);

            return this;

        }

        private String modulePath() {

            // This is expect FIRST jmods THEN jars, if you change this, some tests could fail

            String jmods = toPath(this.jmods);

            String jars = toPath(this.jars);

            return jmods + File.pathSeparator + jars;

        }

        private String toPath(List<Path> paths) {

            return paths.stream()

                    .map(Path::toString)

                    .collect(Collectors.joining(File.pathSeparator));

        }

        private String[] optionsJMod(String cmd) {

            List<String> options = new ArrayList<>();

            options.add(cmd);

            if (!cmds.isEmpty()) {

                options.add(CMDS_OPTION);

                options.add(toPath(cmds));

            }

            if (!config.isEmpty()) {

                options.add(CONFIG_OPTION);

                options.add(toPath(config));

            }

            if (hashModules != null) {

                options.add(HASH_MODULES_OPTION);

                options.add(hashModules);

            }

            if (mainClass != null) {

                options.add(MAIN_CLASS_OPTION);

                options.add(mainClass);

            }

            if (!libs.isEmpty()) {

                options.add(LIBS_OPTION);

                options.add(toPath(libs));

            }

            if (!classpath.isEmpty()) {

                options.add(CLASS_PATH_OPTION);

                options.add(toPath(classpath));

            }

            if (!jars.isEmpty() || !jmods.isEmpty()) {

                options.add(MODULE_PATH_OPTION);

                options.add(modulePath());

            }

            if (moduleVersion != null) {

                options.add(MODULE_VERSION_OPTION);

                options.add(moduleVersion);

            }

            options.addAll(this.options);

            if (output != null) {

                options.add(output.toString());

            }

            return options.toArray(new String[options.size()]);

        }

        public Result create() {

            return cmd("create");

        }

        public Result list() {

            return cmd("list");

        }

        public Result call() {

            return cmd("");

        }

        private Result cmd(String cmd) {

            String[] args = optionsJMod(cmd);

            System.err.println("jmod options: " + optionsPrettyPrint(args));

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            String msg = new String(baos.toByteArray());

            return new Result(exitCode, msg, output);

        }

    }

    public static String getPackageName(String canonicalName) {

        int index = canonicalName.lastIndexOf('.');

        return index > 0 ? canonicalName.substring(0, index) : "";

    }

    public static String getSimpleName(String canonicalName) {

        int index = canonicalName.lastIndexOf('.');

        return canonicalName.substring(index + 1);

    }

    public static class JImageTask {

        private final List<Path> pluginModulePath = new ArrayList<>();

        private final List<String> options = new ArrayList<>();

        private Path dir;

        private Path image;

        public JImageTask pluginModulePath(Path p) {

            this.pluginModulePath.add(p);

            return this;

        }

        public JImageTask image(Path image) {

            this.image = image;

            return this;

        }

        public JImageTask dir(Path dir) {

            this.dir = dir;

            return this;

        }

        public JImageTask option(String o) {

            this.options.add(o);

            return this;

        }