/*

 * Copyright (c) 1999, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javac.main;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

import java.io.PrintWriter;

import java.net.URL;

import java.nio.file.NoSuchFileException;

import java.security.DigestInputStream;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.util.Set;

import javax.tools.JavaFileManager;

import com.sun.tools.javac.api.BasicJavacTask;

import com.sun.tools.javac.file.CacheFSInfo;

import com.sun.tools.javac.file.BaseFileManager;

import com.sun.tools.javac.file.JavacFileManager;

import com.sun.tools.javac.jvm.Target;

import com.sun.tools.javac.platform.PlatformDescription;

import com.sun.tools.javac.processing.AnnotationProcessingError;

import com.sun.tools.javac.util.*;

import com.sun.tools.javac.util.Log.PrefixKind;

import com.sun.tools.javac.util.Log.WriterKind;

/** This class provides a command line interface to the javac compiler.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class Main {

    /** The name of the compiler, for use in diagnostics.

     */

    String ownName;

    /** The writer to use for normal output.

     */

    PrintWriter stdOut;

    /** The writer to use for diagnostic output.

     */

    PrintWriter stdErr;

    /** The log to use for diagnostic output.

     */

    public Log log;

    /**

     * If true, certain errors will cause an exception, such as command line

     * arg errors, or exceptions in user provided code.

     */

    boolean apiMode;

    /** Result codes.

     */

    public enum Result {

        OK(0),        // Compilation completed with no errors.

        ERROR(1),     // Completed but reported errors.

        CMDERR(2),    // Bad command-line arguments

        SYSERR(3),    // System error or resource exhaustion.

        ABNORMAL(4);  // Compiler terminated abnormally

        Result(int exitCode) {

            this.exitCode = exitCode;

        }

        public boolean isOK() {

            return (exitCode == 0);

        }

        public final int exitCode;

    }

    /**

     * Construct a compiler instance.

     * @param name the name of this tool

     */

    public Main(String name) {

        this.ownName = name;

    }

    /**

     * Construct a compiler instance.

     * @param name the name of this tool

     * @param out a stream to which to write messages

     */

    public Main(String name, PrintWriter out) {

        this.ownName = name;

        this.stdOut = this.stdErr = out;

    }

    /** Report a usage error.

     */

    void error(String key, Object... args) {

        if (apiMode) {

            String msg = log.localize(PrefixKind.JAVAC, key, args);

            throw new PropagatedException(new IllegalStateException(msg));

        }

        warning(key, args);

        log.printLines(PrefixKind.JAVAC, "msg.usage", ownName);

    }

    /** Report a warning.

     */

    void warning(String key, Object... args) {

        log.printRawLines(ownName + ": " + log.localize(PrefixKind.JAVAC, key, args));

    }

    /**

     * Programmatic interface for main function.

     * @param args  the command line parameters

     * @return the result of the compilation

     */

    public Result compile(String[] args) {

        Context context = new Context();

        JavacFileManager.preRegister(context); // can't create it until Log has been set up

        Result result = compile(args, context);

        if (fileManager instanceof JavacFileManager) {

            try {

                // A fresh context was created above, so jfm must be a JavacFileManager

                ((JavacFileManager)fileManager).close();

            } catch (IOException ex) {

                bugMessage(ex);

            }

        }

        return result;

    }

    /**

     * Internal version of compile, allowing context to be provided.

     * Note that the context needs to have a file manager set up.

     * @param argv  the command line parameters

     * @param context the context

     * @return the result of the compilation

     */

    public Result compile(String[] argv, Context context) {

        if (stdOut != null) {

            context.put(Log.outKey, stdOut);

        }

        if (stdErr != null) {

            context.put(Log.errKey, stdErr);

        }

        log = Log.instance(context);

        if (argv.length == 0) {

            OptionHelper h = new OptionHelper.GrumpyHelper(log) {

                @Override

                public String getOwnName() { return ownName; }

                @Override

                public void put(String name, String value) { }

            };

            Option.HELP.process(h, "-help");

            return Result.CMDERR;

        }

        // prefix argv with contents of _JAVAC_OPTIONS if set

        String envOpt = System.getenv("_JAVAC_OPTIONS");

        if (envOpt != null && !envOpt.trim().isEmpty()) {

            String[] envv = envOpt.split("\\s+");

            String[] result = new String[envv.length + argv.length];

            System.arraycopy(envv, 0, result, 0, envv.length);

            System.arraycopy(argv, 0, result, envv.length, argv.length);

            argv = result;

        }

        // expand @-files

        try {

            argv = CommandLine.parse(argv);

        } catch (FileNotFoundException | NoSuchFileException e) {

            warning("err.file.not.found", e.getMessage());

            return Result.SYSERR;

        } catch (IOException ex) {

            log.printLines(PrefixKind.JAVAC, "msg.io");

            ex.printStackTrace(log.getWriter(WriterKind.NOTICE));

            return Result.SYSERR;

        }

        Arguments args = Arguments.instance(context);

        args.init(ownName, argv);

        if (log.nerrors > 0)

            return Result.CMDERR;

        Options options = Options.instance(context);

        // init Log

        boolean forceStdOut = options.isSet("stdout");

        if (forceStdOut) {

            log.flush();

            log.setWriters(new PrintWriter(System.out, true));

        }

        // init CacheFSInfo

        // allow System property in following line as a Mustang legacy

        boolean batchMode = (options.isUnset("nonBatchMode")

                    && System.getProperty("nonBatchMode") == null);

        if (batchMode)

            CacheFSInfo.preRegister(context);

        boolean ok = true;

        // init file manager

        fileManager = context.get(JavaFileManager.class);

        if (fileManager instanceof BaseFileManager) {

            ((BaseFileManager) fileManager).setContext(context); // reinit with options

            ok &= ((BaseFileManager) fileManager).handleOptions(args.getDeferredFileManagerOptions());

        }

        // handle this here so it works even if no other options given

        String showClass = options.get("showClass");

        if (showClass != null) {

            if (showClass.equals("showClass")) // no value given for option

                showClass = "com.sun.tools.javac.Main";

            showClass(showClass);

        }

        ok &= args.validate();

        if (!ok || log.nerrors > 0)

            return Result.CMDERR;

        if (args.isEmpty())

            return Result.OK;

        // init Dependencies

        if (options.isSet("debug.completionDeps")) {

            Dependencies.GraphDependencies.preRegister(context);

        }

        // init plugins

        Set<List<String>> pluginOpts = args.getPluginOpts();

        if (!pluginOpts.isEmpty() || context.get(PlatformDescription.class) != null) {

            BasicJavacTask t = (BasicJavacTask) BasicJavacTask.instance(context);

            t.initPlugins(pluginOpts);

        }

        // init multi-release jar handling

        if (fileManager.isSupportedOption(Option.MULTIRELEASE.primaryName) == 1) {

            Target target = Target.instance(context);

            List<String> list = List.of(target.multiReleaseValue());

            fileManager.handleOption(Option.MULTIRELEASE.primaryName, list.iterator());

        }

        // init JavaCompiler

        JavaCompiler comp = JavaCompiler.instance(context);

        // init doclint

        List<String> docLintOpts = args.getDocLintOpts();

        if (!docLintOpts.isEmpty()) {

            BasicJavacTask t = (BasicJavacTask) BasicJavacTask.instance(context);

            t.initDocLint(docLintOpts);

        }

        if (options.get(Option.XSTDOUT) != null) {

            // Stdout reassigned - ask compiler to close it when it is done

            comp.closeables = comp.closeables.prepend(log.getWriter(WriterKind.NOTICE));

        }

        try {

            comp.compile(args.getFileObjects(), args.getClassNames(), null);

            if (log.expectDiagKeys != null) {

                if (log.expectDiagKeys.isEmpty()) {

                    log.printRawLines("all expected diagnostics found");

                    return Result.OK;

                } else {

                    log.printRawLines("expected diagnostic keys not found: " + log.expectDiagKeys);

                    return Result.ERROR;

                }

            }

            return (comp.errorCount() == 0) ? Result.OK : Result.ERROR;

        } catch (OutOfMemoryError | StackOverflowError ex) {

            resourceMessage(ex);

            return Result.SYSERR;

        } catch (FatalError ex) {

            feMessage(ex, options);

            return Result.SYSERR;

        } catch (AnnotationProcessingError ex) {

            apMessage(ex);

            return Result.SYSERR;

        } catch (PropagatedException ex) {

            // TODO: what about errors from plugins?   should not simply rethrow the error here

            throw ex.getCause();

        } catch (Throwable ex) {

            // Nasty.  If we've already reported an error, compensate

            // for buggy compiler error recovery by swallowing thrown

            // exceptions.

            if (comp == null || comp.errorCount() == 0 || options.isSet("dev"))

                bugMessage(ex);

            return Result.ABNORMAL;

        } finally {

            if (comp != null) {

                try {

                    comp.close();

                } catch (ClientCodeException ex) {

                    throw new RuntimeException(ex.getCause());

                }

            }

        }

    }

    /** Print a message reporting an internal error.

     */

    void bugMessage(Throwable ex) {

        log.printLines(PrefixKind.JAVAC, "msg.bug", JavaCompiler.version());

        ex.printStackTrace(log.getWriter(WriterKind.NOTICE));

    }

    /** Print a message reporting a fatal error.

     */

    void feMessage(Throwable ex, Options options) {

        log.printRawLines(ex.getMessage());

        if (ex.getCause() != null && options.isSet("dev")) {

            ex.getCause().printStackTrace(log.getWriter(WriterKind.NOTICE));

        }

    }

    /** Print a message reporting an input/output error.

     */

    void ioMessage(Throwable ex) {

        log.printLines(PrefixKind.JAVAC, "msg.io");

        ex.printStackTrace(log.getWriter(WriterKind.NOTICE));

    }

    /** Print a message reporting an out-of-resources error.

     */

    void resourceMessage(Throwable ex) {

        log.printLines(PrefixKind.JAVAC, "msg.resource");

        ex.printStackTrace(log.getWriter(WriterKind.NOTICE));

    }

    /** Print a message reporting an uncaught exception from an

     * annotation processor.

     */

    void apMessage(AnnotationProcessingError ex) {

        log.printLines(PrefixKind.JAVAC, "msg.proc.annotation.uncaught.exception");

        ex.getCause().printStackTrace(log.getWriter(WriterKind.NOTICE));

    }

    /** Print a message reporting an uncaught exception from an

     * annotation processor.

     */

    void pluginMessage(Throwable ex) {

        log.printLines(PrefixKind.JAVAC, "msg.plugin.uncaught.exception");

        ex.printStackTrace(log.getWriter(WriterKind.NOTICE));

    }

    /** Display the location and checksum of a class. */

    void showClass(String className) {

        PrintWriter pw = log.getWriter(WriterKind.NOTICE);

        pw.println("javac: show class: " + className);

        URL url = getClass().getResource('/' + className.replace('.', '/') + ".class");

        if (url != null) {

            pw.println("  " + url);

        }

        try (InputStream in = getClass().getResourceAsStream('/' + className.replace('.', '/') + ".class")) {

            final String algorithm = "MD5";

            byte[] digest;

            MessageDigest md = MessageDigest.getInstance(algorithm);

            try (DigestInputStream din = new DigestInputStream(in, md)) {

                byte[] buf = new byte[8192];

                int n;

                do { n = din.read(buf); } while (n > 0);

                digest = md.digest();

            }

            StringBuilder sb = new StringBuilder();

            for (byte b: digest)

                sb.append(String.format("%02x", b));

            pw.println("  " + algorithm + " checksum: " + sb);

        } catch (NoSuchAlgorithmException | IOException e) {

            pw.println("  cannot compute digest: " + e);

        }

    }

    // TODO: update this to JavacFileManager

    private JavaFileManager fileManager;

    /* ************************************************************************

     * Internationalization

     *************************************************************************/

    public static final String javacBundleName =

        "com.sun.tools.javac.resources.javac";

}