/*
 * Copyright (c) 1999, 2018, 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.CodeSource;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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.main.CommandLine.UnmatchedQuote;
import com.sun.tools.javac.platform.PlatformDescription;
import com.sun.tools.javac.processing.AnnotationProcessingError;
import com.sun.tools.javac.resources.CompilerProperties.Errors;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticInfo;
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.
 
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.
/** 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.
/** The name of the compiler, for use in diagnostics.
     */
    String ownName;

    
The writer to use for normal output.
/** The writer to use for normal output.
     */
    PrintWriter stdOut;

    
The writer to use for diagnostic output.
/** The writer to use for diagnostic output.
     */
    PrintWriter stdErr;

    
The log to use for diagnostic output.
/** 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.
/**
     * If true, certain errors will cause an exception, such as command line
     * arg errors, or exceptions in user provided code.
     */
    boolean apiMode;

    private static final String ENV_OPT_NAME = "JDK_JAVAC_OPTIONS";

    
Result codes.
/** 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.
Params:
name – the name of this tool/**
     * Construct a compiler instance.
     * @param name the name of this tool
     */
    public Main(String name) {
        this.ownName = name;
    }

    
Construct a compiler instance.
Params:
name – the name of this tool
out – a stream to which to write messages/**
     * 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;
    }

    
Construct a compiler instance.
Params:
name – the name of this tool
out – a stream to which to write expected output
err – a stream to which to write diagnostic output/**
     * Construct a compiler instance.
     * @param name the name of this tool
     * @param out a stream to which to write expected output
     * @param err a stream to which to write diagnostic output
     */
    public Main(String name, PrintWriter out, PrintWriter err) {
        this.ownName = name;
        this.stdOut = out;
        this.stdErr = err;
    }

    
Report a usage error.
/** Report a usage error.
     */
    void reportDiag(DiagnosticInfo diag) {
        if (apiMode) {
            String msg = log.localize(diag);
            throw new PropagatedException(new IllegalStateException(msg));
        }
        reportHelper(diag);
        log.printLines(PrefixKind.JAVAC, "msg.usage", ownName);
    }

    
Report helper.
/** Report helper.
     */
    void reportHelper(DiagnosticInfo diag) {
        String msg = log.localize(diag);
        String errorPrefix = log.localize(Errors.Error);
        msg = msg.startsWith(errorPrefix) ? msg : errorPrefix + msg;
        log.printRawLines(msg);
    }


    
Programmatic interface for main function.
Params:
args –  the command line parameters
Returns:
the result of the compilation/**
     * 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);
        try {
            // A fresh context was created above, so the file manager can be safely closed:
            if (fileManager != null)
                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.
Params:
argv –  the command line parameters
context – the context
Returns:
the result of the compilation/**
     * 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) { }
            };
            try {
                Option.HELP.process(h, "-help");
            } catch (Option.InvalidValueException ignore) {
            }
            return Result.CMDERR;
        }

        // prefix argv with contents of environment variable and expand @-files
        try {
            argv = CommandLine.parse(ENV_OPT_NAME, argv);
        } catch (UnmatchedQuote ex) {
            reportDiag(Errors.UnmatchedQuote(ex.variableName));
            return Result.CMDERR;
        } catch (FileNotFoundException | NoSuchFileException e) {
            reportHelper(Errors.FileNotFound(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);
        JavaFileManager undel = fileManager instanceof DelegatingJavaFileManager ?
                ((DelegatingJavaFileManager) fileManager).getBaseFileManager() : fileManager;
        if (undel instanceof BaseFileManager) {
            ((BaseFileManager) undel).setContext(context); // reinit with options
            ok &= ((BaseFileManager) undel).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, List.nil());

            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 (IllegalAccessError iae) {
            if (twoClassLoadersInUse(iae)) {
                bugMessage(iae);
            }
            return Result.ABNORMAL;
        } 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());
                }
            }
        }
    }

    private boolean twoClassLoadersInUse(IllegalAccessError iae) {
        String msg = iae.getMessage();
        Pattern pattern = Pattern.compile("(?i)(?<=tried to access class )([a-z_$][a-z\\d_$]*\\.)*[a-z_$][a-z\\d_$]*");
        Matcher matcher = pattern.matcher(msg);
        if (matcher.find()) {
            try {
                String otherClassName = matcher.group(0);
                Class<?> otherClass = Class.forName(otherClassName);
                ClassLoader otherClassLoader = otherClass.getClassLoader();
                ClassLoader javacClassLoader = this.getClass().getClassLoader();
                if (javacClassLoader != otherClassLoader) {
                    CodeSource otherClassCodeSource = otherClass.getProtectionDomain().getCodeSource();
                    CodeSource javacCodeSource = this.getClass().getProtectionDomain().getCodeSource();
                    if (otherClassCodeSource != null && javacCodeSource != null) {
                        log.printLines(Errors.TwoClassLoaders2(otherClassCodeSource.getLocation(),
                                javacCodeSource.getLocation()));
                    } else {
                        log.printLines(Errors.TwoClassLoaders1);
                    }
                    return true;
                }
            } catch (Throwable t) {
                return false;
            }
        }
        return false;
    }

    
Print a message reporting an internal error.
/** 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.
/** 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.
/** 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.
/** 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.
/** 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.
/** 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. /** 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";
}