/*

 * Copyright (c) 2012, 2013, 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.

 */

package com.sun.tools.jdeps;

import com.sun.tools.classfile.AccessFlags;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPoolException;

import com.sun.tools.classfile.Dependencies;

import com.sun.tools.classfile.Dependencies.ClassFileError;

import com.sun.tools.classfile.Dependency;

import com.sun.tools.jdeps.PlatformClassPath.JDKArchive;

import java.io.*;

import java.nio.file.DirectoryStream;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.text.MessageFormat;

import java.util.*;

import java.util.regex.Pattern;

/**

 * Implementation for the jdeps tool for static class dependency analysis.

 */

class JdepsTask {

    static class BadArgs extends Exception {

        static final long serialVersionUID = 8765093759964640721L;

        BadArgs(String key, Object... args) {

            super(JdepsTask.getMessage(key, args));

            this.key = key;

            this.args = args;

        }

        BadArgs showUsage(boolean b) {

            showUsage = b;

            return this;

        }

        final String key;

        final Object[] args;

        boolean showUsage;

    }

    static abstract class Option {

        Option(boolean hasArg, String... aliases) {

            this.hasArg = hasArg;

            this.aliases = aliases;

        }

        boolean isHidden() {

            return false;

        }

        boolean matches(String opt) {

            for (String a : aliases) {

                if (a.equals(opt))

                    return true;

                if (hasArg && opt.startsWith(a + "="))

                    return true;

            }

            return false;

        }

        boolean ignoreRest() {

            return false;

        }

        abstract void process(JdepsTask task, String opt, String arg) throws BadArgs;

        final boolean hasArg;

        final String[] aliases;

    }

    static abstract class HiddenOption extends Option {

        HiddenOption(boolean hasArg, String... aliases) {

            super(hasArg, aliases);

        }

        boolean isHidden() {

            return true;

        }

    }

    static Option[] recognizedOptions = {

        new Option(false, "-h", "-?", "-help") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.help = true;

            }

        },

        new Option(true, "-dotoutput") {

            void process(JdepsTask task, String opt, String arg) throws BadArgs {

                Path p = Paths.get(arg);

                if (Files.exists(p) && (!Files.isDirectory(p) || !Files.isWritable(p))) {

                    throw new BadArgs("err.dot.output.path", arg);

                }

                task.options.dotOutputDir = arg;

            }

        },

        new Option(false, "-s", "-summary") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.showSummary = true;

                task.options.verbose = Analyzer.Type.SUMMARY;

            }

        },

        new Option(false, "-v", "-verbose",

                          "-verbose:package",

                          "-verbose:class")

        {

            void process(JdepsTask task, String opt, String arg) throws BadArgs {

                switch (opt) {

                    case "-v":

                    case "-verbose":

                        task.options.verbose = Analyzer.Type.VERBOSE;

                        break;

                    case "-verbose:package":

                            task.options.verbose = Analyzer.Type.PACKAGE;

                            break;

                    case "-verbose:class":

                            task.options.verbose = Analyzer.Type.CLASS;

                            break;

                    default:

                        throw new BadArgs("err.invalid.arg.for.option", opt);

                }

            }

        },

        new Option(true, "-cp", "-classpath") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.classpath = arg;

            }

        },

        new Option(true, "-p", "-package") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.packageNames.add(arg);

            }

        },

        new Option(true, "-e", "-regex") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.regex = arg;

            }

        },

        new Option(true, "-include") {

            void process(JdepsTask task, String opt, String arg) throws BadArgs {

                task.options.includePattern = Pattern.compile(arg);

            }

        },

        new Option(false, "-P", "-profile") {

            void process(JdepsTask task, String opt, String arg) throws BadArgs {

                task.options.showProfile = true;

                if (Profile.getProfileCount() == 0) {

                    throw new BadArgs("err.option.unsupported", opt, getMessage("err.profiles.msg"));

                }

            }

        },

        new Option(false, "-apionly") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.apiOnly = true;

            }

        },

        new Option(false, "-R", "-recursive") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.depth = 0;

            }

        },

        new Option(false, "-version") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.version = true;

            }

        },

        new HiddenOption(false, "-fullversion") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.fullVersion = true;

            }

        },

        new HiddenOption(false, "-showlabel") {

            void process(JdepsTask task, String opt, String arg) {

                task.options.showLabel = true;

            }

        },

        new HiddenOption(true, "-depth") {

            void process(JdepsTask task, String opt, String arg) throws BadArgs {

                try {

                    task.options.depth = Integer.parseInt(arg);

                } catch (NumberFormatException e) {

                    throw new BadArgs("err.invalid.arg.for.option", opt);

                }

            }

        },

    };

    private static final String PROGNAME = "jdeps";

    private final Options options = new Options();

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

    private PrintWriter log;

    void setLog(PrintWriter out) {

        log = out;

    }

    /**

     * Result codes.

     */

    static final int EXIT_OK = 0, // Completed with no errors.

                     EXIT_ERROR = 1, // Completed but reported errors.

                     EXIT_CMDERR = 2, // Bad command-line arguments

                     EXIT_SYSERR = 3, // System error or resource exhaustion.

                     EXIT_ABNORMAL = 4;// terminated abnormally

    int run(String[] args) {

        if (log == null) {

            log = new PrintWriter(System.out);

        }

        try {

            handleOptions(args);

            if (options.help) {

                showHelp();

            }

            if (options.version || options.fullVersion) {

                showVersion(options.fullVersion);

            }

            if (classes.isEmpty() && options.includePattern == null) {

                if (options.help || options.version || options.fullVersion) {

                    return EXIT_OK;

                } else {

                    showHelp();

                    return EXIT_CMDERR;

                }

            }

            if (options.regex != null && options.packageNames.size() > 0) {

                showHelp();

                return EXIT_CMDERR;

            }

            if (options.showSummary && options.verbose != Analyzer.Type.SUMMARY) {

                showHelp();

                return EXIT_CMDERR;

            }

            boolean ok = run();

            return ok ? EXIT_OK : EXIT_ERROR;

        } catch (BadArgs e) {

            reportError(e.key, e.args);

            if (e.showUsage) {

                log.println(getMessage("main.usage.summary", PROGNAME));

            }

            return EXIT_CMDERR;

        } catch (IOException e) {

            return EXIT_ABNORMAL;

        } finally {

            log.flush();

        }

    }

    private final List<Archive> sourceLocations = new ArrayList<>();

    private boolean run() throws IOException {

        findDependencies();

        Analyzer analyzer = new Analyzer(options.verbose);

        analyzer.run(sourceLocations);

        if (options.dotOutputDir != null) {

            Path dir = Paths.get(options.dotOutputDir);

            Files.createDirectories(dir);

            generateDotFiles(dir, analyzer);

        } else {

            printRawOutput(log, analyzer);

        }

        return true;

    }

    private void generateDotFiles(Path dir, Analyzer analyzer) throws IOException {

        Path summary = dir.resolve("summary.dot");

        boolean verbose = options.verbose == Analyzer.Type.VERBOSE;

        DotGraph<?> graph = verbose ? new DotSummaryForPackage()

                                    : new DotSummaryForArchive();

        for (Archive archive : sourceLocations) {

            analyzer.visitArchiveDependences(archive, graph);

            if (verbose || options.showLabel) {

                // traverse detailed dependences to generate package-level

                // summary or build labels for edges

                analyzer.visitDependences(archive, graph);

            }

        }

        try (PrintWriter sw = new PrintWriter(Files.newOutputStream(summary))) {

            graph.writeTo(sw);

        }

        // output individual .dot file for each archive

        if (options.verbose != Analyzer.Type.SUMMARY) {

            for (Archive archive : sourceLocations) {

                if (analyzer.hasDependences(archive)) {

                    Path dotfile = dir.resolve(archive.getFileName() + ".dot");

                    try (PrintWriter pw = new PrintWriter(Files.newOutputStream(dotfile));

                         DotFileFormatter formatter = new DotFileFormatter(pw, archive)) {

                        analyzer.visitDependences(archive, formatter);

                    }

                }

            }

        }

    }

    private void printRawOutput(PrintWriter writer, Analyzer analyzer) {

        for (Archive archive : sourceLocations) {

            RawOutputFormatter formatter = new RawOutputFormatter(writer);

            analyzer.visitArchiveDependences(archive, formatter);

            if (options.verbose != Analyzer.Type.SUMMARY) {

                analyzer.visitDependences(archive, formatter);

            }

        }

    }

    private boolean isValidClassName(String name) {

        if (!Character.isJavaIdentifierStart(name.charAt(0))) {

            return false;

        }

        for (int i=1; i < name.length(); i++) {

            char c = name.charAt(i);

            if (c != '.'  && !Character.isJavaIdentifierPart(c)) {

                return false;

            }

        }

        return true;

    }

    private Dependency.Filter getDependencyFilter() {

         if (options.regex != null) {

            return Dependencies.getRegexFilter(Pattern.compile(options.regex));

        } else if (options.packageNames.size() > 0) {

            return Dependencies.getPackageFilter(options.packageNames, false);

        } else {

            return new Dependency.Filter() {

                @Override

                public boolean accepts(Dependency dependency) {

                    return !dependency.getOrigin().equals(dependency.getTarget());

                }

            };

        }

    }

    private boolean matches(String classname, AccessFlags flags) {

        if (options.apiOnly && !flags.is(AccessFlags.ACC_PUBLIC)) {

            return false;

        } else if (options.includePattern != null) {

            return options.includePattern.matcher(classname.replace('/', '.')).matches();

        } else {

            return true;

        }

    }

    private void findDependencies() throws IOException {

        Dependency.Finder finder =

            options.apiOnly ? Dependencies.getAPIFinder(AccessFlags.ACC_PROTECTED)

                            : Dependencies.getClassDependencyFinder();

        Dependency.Filter filter = getDependencyFilter();

        List<Archive> archives = new ArrayList<>();

        Deque<String> roots = new LinkedList<>();

        for (String s : classes) {

            Path p = Paths.get(s);

            if (Files.exists(p)) {

                archives.add(new Archive(p, ClassFileReader.newInstance(p)));

            } else {

                if (isValidClassName(s)) {

                    roots.add(s);

                } else {

                    warning("warn.invalid.arg", s);

                }

            }

        }

        sourceLocations.addAll(archives);

        List<Archive> classpaths = new ArrayList<>(); // for class file lookup

        classpaths.addAll(getClassPathArchives(options.classpath));

        if (options.includePattern != null) {

            archives.addAll(classpaths);

        }

        classpaths.addAll(PlatformClassPath.getArchives());

        // add all classpath archives to the source locations for reporting

        sourceLocations.addAll(classpaths);

        // Work queue of names of classfiles to be searched.

        // Entries will be unique, and for classes that do not yet have

        // dependencies in the results map.

        Deque<String> deque = new LinkedList<>();

        Set<String> doneClasses = new HashSet<>();

        // get the immediate dependencies of the input files

        for (Archive a : archives) {

            for (ClassFile cf : a.reader().getClassFiles()) {

                String classFileName;

                try {

                    classFileName = cf.getName();

                } catch (ConstantPoolException e) {

                    throw new ClassFileError(e);

                }

                if (matches(classFileName, cf.access_flags)) {

                    if (!doneClasses.contains(classFileName)) {

                        doneClasses.add(classFileName);

                    }

                    for (Dependency d : finder.findDependencies(cf)) {

                        if (filter.accepts(d)) {

                            String cn = d.getTarget().getName();

                            if (!doneClasses.contains(cn) && !deque.contains(cn)) {

                                deque.add(cn);

                            }

                            a.addClass(d.getOrigin(), d.getTarget());

                        }

                    }

                }

            }

        }

        // add Archive for looking up classes from the classpath

        // for transitive dependency analysis

        Deque<String> unresolved = roots;

        int depth = options.depth > 0 ? options.depth : Integer.MAX_VALUE;

        do {

            String name;

            while ((name = unresolved.poll()) != null) {

                if (doneClasses.contains(name)) {

                    continue;

                }

                ClassFile cf = null;

                for (Archive a : classpaths) {

                    cf = a.reader().getClassFile(name);

                    if (cf != null) {

                        String classFileName;

                        try {

                            classFileName = cf.getName();

                        } catch (ConstantPoolException e) {

                            throw new ClassFileError(e);

                        }

                        if (!doneClasses.contains(classFileName)) {

                            // if name is a fully-qualified class name specified

                            // from command-line, this class might already be parsed

                            doneClasses.add(classFileName);

                            for (Dependency d : finder.findDependencies(cf)) {

                                if (depth == 0) {

                                    // ignore the dependency

                                    a.addClass(d.getOrigin());

                                    break;

                                } else if (filter.accepts(d)) {

                                    a.addClass(d.getOrigin(), d.getTarget());

                                    String cn = d.getTarget().getName();

                                    if (!doneClasses.contains(cn) && !deque.contains(cn)) {

                                        deque.add(cn);

                                    }

                                }

                            }

                        }

                        break;

                    }

                }

                if (cf == null) {

                    doneClasses.add(name);

                }

            }

            unresolved = deque;

            deque = new LinkedList<>();

        } while (!unresolved.isEmpty() && depth-- > 0);

    }

    public void handleOptions(String[] args) throws BadArgs {

        // process options

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

            if (args[i].charAt(0) == '-') {

                String name = args[i];

                Option option = getOption(name);

                String param = null;

                if (option.hasArg) {

                    if (name.startsWith("-") && name.indexOf('=') > 0) {

                        param = name.substring(name.indexOf('=') + 1, name.length());

                    } else if (i + 1 < args.length) {

                        param = args[++i];

                    }

                    if (param == null || param.isEmpty() || param.charAt(0) == '-') {

                        throw new BadArgs("err.missing.arg", name).showUsage(true);

                    }

                }

                option.process(this, name, param);