/*

 * Copyright (c) 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.

 *

 * 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 jdk.tools.jaotc;

import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;

import static org.graalvm.compiler.core.common.GraalOptions.ImmutableCode;

import static org.graalvm.compiler.hotspot.meta.HotSpotAOTProfilingPlugin.Options.TieredAOT;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.lang.management.ManagementFactory;

import java.lang.management.MemoryUsage;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.text.MessageFormat;

import java.util.ArrayList;

import java.util.Date;

import java.util.LinkedList;

import java.util.List;

import java.util.Set;

import java.util.stream.Stream;

import jdk.tools.jaotc.binformat.BinaryContainer;

import jdk.tools.jaotc.binformat.ByteContainer;

import jdk.tools.jaotc.collect.ClassCollector;

import jdk.tools.jaotc.utils.Timer;

import org.graalvm.compiler.api.runtime.GraalJVMCICompiler;

import org.graalvm.compiler.hotspot.HotSpotGraalRuntimeProvider;

import org.graalvm.compiler.hotspot.HotSpotHostBackend;

import org.graalvm.compiler.runtime.RuntimeProvider;

import jdk.vm.ci.meta.MetaAccessProvider;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import jdk.vm.ci.meta.ResolvedJavaType;

import jdk.vm.ci.runtime.JVMCI;

public class Main implements LogPrinter {

    static {

        GeneratePIC.setValue(true);

        ImmutableCode.setValue(true);

    }

    static class BadArgs extends Exception {

        private static final long serialVersionUID = 1L;

        final String key;

        final Object[] args;

        boolean showUsage;

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

            super(MessageFormat.format(key, args));

            this.key = key;

            this.args = args;

        }

        BadArgs showUsage(boolean b) {

            showUsage = b;

            return this;

        }

    }

    abstract static class Option {

        final String help;

        final boolean hasArg;

        final String[] aliases;

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

            this.help = help;

            this.hasArg = hasArg;

            this.aliases = aliases;

        }

        boolean isHidden() {

            return false;

        }

        boolean matches(String opt) {

            for (String a : aliases) {

                if (a.equals(opt)) {

                    return true;

                } else if (opt.startsWith("--") && hasArg && opt.startsWith(a + "=")) {

                    return true;

                }

            }

            return false;

        }

        boolean ignoreRest() {

            return false;

        }

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

    }

    static Option[] recognizedOptions = {new Option("  --module <name>            Module to compile", true, "--module") {

        @Override

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

            task.options.module = arg;

        }

    }, new Option("  --module-path <path>       Specify where to find module to compile", true, "--module-path") {

        @Override

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

            task.options.modulepath = arg;

        }

    }, new Option("  --output <file>            Output file name", true, "--output") {

        @Override

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

            String name = arg;

            if (name.endsWith(".so")) {

                name = name.substring(0, name.length() - ".so".length());

            }

            task.options.outputName = name;

        }

    }, new Option("  --compile-commands <file>  Name of file with compile commands", true, "--compile-commands") {

        @Override

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

            task.options.methodList = arg;

        }

        @Override

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

            TieredAOT.setValue(true);

        }

    }, new Option("  --classpath <path>         Specify where to find user class files", true, "--classpath", "--class-path") {

        @Override

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

            task.options.classpath = arg;

        }

    }, new Option("  --threads <number>         Number of compilation threads to be used", true, "--threads") {

        @Override

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

            int threads = Integer.parseInt(arg);

            final int available = Runtime.getRuntime().availableProcessors();

            if (threads <= 0) {

                task.warning("invalid number of threads specified: {0}, using: {1}", threads, available);

                threads = available;

            }

            if (threads > available) {

                task.warning("too many threads specified: {0}, limiting to: {1}", threads, available);

            }

            task.options.threads = Integer.min(threads, available);

        }

    }, new Option("  --ignore-errors            Ignores all exceptions thrown during class loading", false, "--ignore-errors") {

        @Override

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

            task.options.ignoreClassLoadingErrors = true;

        }

    }, new Option("  --exit-on-error            Exit on compilation errors", false, "--exit-on-error") {

        @Override

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

            task.options.exitOnError = true;

        }

    }, new Option("  --info                     Print information during compilation", false, "--info") {

        @Override

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

            task.options.info = true;

        }

    }, new Option("  --verbose                  Print verbose information", false, "--verbose") {

        @Override

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

            task.options.info = true;

            task.options.verbose = true;

        }

    }, new Option("  --debug                    Print debug information", false, "--debug") {

        @Override

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

            task.options.info = true;

            task.options.verbose = true;

            task.options.debug = true;

        }

    }, new Option("  --help                     Print this usage message", false, "--help") {

        @Override

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

            task.options.help = true;

        }

    }, new Option("  --version                  Version information", false, "--version") {

        @Override

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

            task.options.version = true;

        }

    }, new Option("  -J<flag>                   Pass <flag> directly to the runtime system", false, "-J") {

        @Override

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

        }

    }};

    public static class Options {

        public List<String> files = new LinkedList<>();

        public String module = null;

        public String modulepath = "modules";

        public String outputName = "unnamed";

        public String methodList;

        public String classpath = ".";

        /**

         * We don't see scaling beyond 16 threads.

         */

        private static final int COMPILER_THREADS = 16;

        public boolean ignoreClassLoadingErrors;

        public boolean exitOnError;

    }

    /* package */final Options options = new Options();

    /**

     * Logfile.

     */

    private static FileWriter logFile = null;

    private static final int EXIT_OK = 0;        // No errors.

    private static final int EXIT_CMDERR = 2;    // Bad command-line arguments and/or switches.

    private static final int EXIT_ABNORMAL = 4;  // Terminated abnormally.

    private static final String PROGNAME = "jaotc";

    private static final String JVM_VERSION = System.getProperty("java.runtime.version");

    public static void main(String[] args) throws Exception {

        Main t = new Main();

        final int exitCode = t.run(args);

        System.exit(exitCode);

    }

    private int run(String[] args) {

        if (log == null) {

            log = new PrintWriter(System.out);

        }

        try {

            handleOptions(args);

            if (options.help) {

                showHelp();

                return EXIT_OK;

            }

            if (options.version) {

                showVersion();

                return EXIT_OK;

            }

            printlnInfo("Compiling " + options.outputName + "...");

            final long start = System.currentTimeMillis();

            run();

            final long end = System.currentTimeMillis();

            printlnInfo("Total time: " + (end - start) + " ms");

            return EXIT_OK;

        } catch (BadArgs e) {

            reportError(e.key, e.args);

            if (e.showUsage) {

                showUsage();

            }

            return EXIT_CMDERR;

        } catch (Exception e) {

            e.printStackTrace();

            return EXIT_ABNORMAL;

        } finally {

            log.flush();

        }

    }

    private static String humanReadableByteCount(long bytes) {

        int unit = 1024;

        if (bytes < unit) {

            return bytes + " B";

        }

        int exp = (int) (Math.log(bytes) / Math.log(unit));

        char pre = "KMGTPE".charAt(exp - 1);

        return String.format("%.1f %cB", bytes / Math.pow(unit, exp), pre);

    }

    void printMemoryUsage() {

        if (options.verbose) {

            MemoryUsage memusage = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();

            float freeratio = 1f - (float) memusage.getUsed() / memusage.getCommitted();

            log.format(" [used: %-7s, comm: %-7s, freeRatio ~= %.1f%%]",

                            humanReadableByteCount(memusage.getUsed()),

                            humanReadableByteCount(memusage.getCommitted()),

                            freeratio * 100);

        }

    }

    @SuppressWarnings("try")

    private void run() throws Exception {

        openLog();

        try {

            CompilationSpec compilationRestrictions = collectSpecifiedMethods();

            Set<Class<?>> classesToCompile;

            try (Timer t = new Timer(this, "")) {

                ClassCollector collector = new ClassCollector(this.options, this);

                classesToCompile = collector.collectClassesToCompile();

                printInfo(classesToCompile.size() + " classes found");

            }

            GraalJVMCICompiler graalCompiler = (GraalJVMCICompiler) JVMCI.getRuntime().getCompiler();

            HotSpotGraalRuntimeProvider runtime = (HotSpotGraalRuntimeProvider) graalCompiler.getGraalRuntime();

            HotSpotHostBackend backend = (HotSpotHostBackend) runtime.getCapability(RuntimeProvider.class).getHostBackend();

            MetaAccessProvider metaAccess = backend.getProviders().getMetaAccess();

            GraalFilters filters = new GraalFilters(metaAccess);

            List<AOTCompiledClass> classes;

            try (Timer t = new Timer(this, "")) {

                classes = collectMethodsToCompile(classesToCompile, compilationRestrictions, filters, metaAccess);

            }

            // Free memory!

            try (Timer t = options.verbose ? new Timer(this, "Freeing memory") : null) {

                printMemoryUsage();

                compilationRestrictions = null;

                classesToCompile = null;

                System.gc();

            }

            AOTBackend aotBackend = new AOTBackend(this, backend, filters);

            AOTCompiler compiler = new AOTCompiler(this, aotBackend, options.threads);

            classes = compiler.compileClasses(classes);

            // Free memory!

            try (Timer t = options.verbose ? new Timer(this, "Freeing memory") : null) {

                printMemoryUsage();

                aotBackend = null;

                compiler = null;

                System.gc();

            }

            DataBuilder dataBuilder = new DataBuilder(this, backend, classes, binaryContainer);

            dataBuilder.prepareData();

            // Print information about section sizes

            printContainerInfo(binaryContainer.getHeaderContainer().getContainer());

            printContainerInfo(binaryContainer.getConfigContainer());

            printContainerInfo(binaryContainer.getKlassesOffsetsContainer());

            printContainerInfo(binaryContainer.getMethodsOffsetsContainer());

            printContainerInfo(binaryContainer.getKlassesDependenciesContainer());

            printContainerInfo(binaryContainer.getStubsOffsetsContainer());

            printContainerInfo(binaryContainer.getMethodMetadataContainer());

            printContainerInfo(binaryContainer.getCodeContainer());

            printContainerInfo(binaryContainer.getCodeSegmentsContainer());

            printContainerInfo(binaryContainer.getConstantDataContainer());

            printContainerInfo(binaryContainer.getMetaspaceGotContainer());

            printContainerInfo(binaryContainer.getMetadataGotContainer());

            printContainerInfo(binaryContainer.getMethodStateContainer());

            printContainerInfo(binaryContainer.getOopGotContainer());

            printContainerInfo(binaryContainer.getMetaspaceNamesContainer());

            // Free memory!

            try (Timer t = options.verbose ? new Timer(this, "Freeing memory") : null) {

                printMemoryUsage();

                backend = null;

                for (AOTCompiledClass aotCompClass : classes) {

                    aotCompClass.clear();

                }

                classes.clear();

                classes = null;

                dataBuilder = null;

                binaryContainer.freeMemory();

                System.gc();

            }

            String objectFileName = options.outputName + ".o";

            String libraryFileName = options.outputName + ".so";

            try (Timer t = new Timer(this, "Creating binary: " + objectFileName)) {

                binaryContainer.createBinary(objectFileName, JVM_VERSION);

            }

            // Free memory!

            try (Timer t = options.verbose ? new Timer(this, "Freeing memory") : null) {

                printMemoryUsage();

                binaryContainer = null;

                System.gc();

            }

            try (Timer t = new Timer(this, "Creating shared library: " + libraryFileName)) {

                Process p = Runtime.getRuntime().exec("ld -shared -z noexecstack -o " + libraryFileName + " " + objectFileName);

                final int exitCode = p.waitFor();

                if (exitCode != 0) {

                    InputStream stderr = p.getErrorStream();

                    BufferedReader br = new BufferedReader(new InputStreamReader(stderr));

                    Stream<String> lines = br.lines();

                    StringBuilder sb = new StringBuilder();

                    lines.iterator().forEachRemaining(e -> sb.append(e));

                    throw new InternalError(sb.toString());

                }

                File objFile = new File(objectFileName);

                if (objFile.exists()) {

                    if (!objFile.delete()) {

                        throw new InternalError("Failed to delete " + objectFileName + " file");

                    }

                }

                // Make non-executable for all.

                File libFile = new File(libraryFileName);

                if (libFile.exists()) {

                    if (!libFile.setExecutable(false, false)) {

                        throw new InternalError("Failed to change attribute for " + libraryFileName + " file");

                    }

                }

            }

            printVerbose("Final memory  ");

            printMemoryUsage();

            printlnVerbose("");

        } finally {

            closeLog();

        }

    }

    private void addMethods(AOTCompiledClass aotClass, ResolvedJavaMethod[] methods, CompilationSpec compilationRestrictions, GraalFilters filters) {

        for (ResolvedJavaMethod m : methods) {

            addMethod(aotClass, m, compilationRestrictions, filters);

        }

    }

    private void addMethod(AOTCompiledClass aotClass, ResolvedJavaMethod method, CompilationSpec compilationRestrictions, GraalFilters filters) {

        // Don't compile native or abstract methods.

        if (!method.hasBytecodes()) {

            return;

        }

        if (!compilationRestrictions.shouldCompileMethod(method)) {

            return;

        }

        if (!filters.shouldCompileMethod(method)) {

            return;

        }

        aotClass.addMethod(method);

        printlnVerbose("  added " + method.getName() + method.getSignature().toMethodDescriptor());

    }

    private void printContainerInfo(ByteContainer container) {

        printlnVerbose(container.getContainerName() + ": " + container.getByteStreamSize() + " bytes");

    }

    PrintWriter log;

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

        if (args.length == 0) {

            options.help = true;

            return;

        }

        // Make checkstyle happy.

        int i = 0;

        for (; i < args.length; i++) {

            String arg = args[i];

            if (arg.charAt(0) == '-') {

                Option option = getOption(arg);

                String param = null;

                if (option.hasArg) {

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

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

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

                        param = args[++i];

                    }

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

                        throw new BadArgs("missing argument for option: {0}", arg).showUsage(true);

                    }

                }

                option.process(this, arg, param);

                if (option.ignoreRest()) {