/*

 * 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 sun.launcher;

/*

 *

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

 *  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>

 *

 */

/**

 * A utility package for the java(1), javaw(1) launchers.

 * The following are helper methods that the native launcher uses

 * to perform checks etc. using JNI, see src/share/bin/java.c

 */

import java.io.File;

import java.io.IOException;

import java.io.PrintStream;

import java.io.UnsupportedEncodingException;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.math.BigDecimal;

import java.math.RoundingMode;

import java.nio.charset.Charset;

import java.util.ResourceBundle;

import java.text.MessageFormat;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

import java.util.Locale;

import java.util.Locale.Category;

import java.util.Properties;

import java.util.Set;

import java.util.TreeSet;

import java.util.jar.Attributes;

import java.util.jar.JarFile;

import java.util.jar.Manifest;

public enum LauncherHelper {

    INSTANCE;

    private static final String MAIN_CLASS = "Main-Class";

    private static StringBuilder outBuf = new StringBuilder();

    private static ResourceBundle javarb = null;

    private static final String INDENT = "    ";

    private static final String VM_SETTINGS     = "VM settings:";

    private static final String PROP_SETTINGS   = "Property settings:";

    private static final String LOCALE_SETTINGS = "Locale settings:";

    // sync with java.c and sun.misc.VM

    private static final String diagprop = "sun.java.launcher.diag";

    private static final String defaultBundleName =

            "sun.launcher.resources.launcher";

    private static class ResourceBundleHolder {

        private static final ResourceBundle RB =

                ResourceBundle.getBundle(defaultBundleName);

    }

    /*

     * A method called by the launcher to print out the standard settings,

     * by default -XshowSettings is equivalent to -XshowSettings:all,

     * Specific information may be gotten by using suboptions with possible

     * values vm, properties and locale.

     *

     * printToStderr: choose between stdout and stderr

     *

     * optionFlag: specifies which options to print default is all other

     *    possible values are vm, properties, locale.

     *

     * initialHeapSize: in bytes, as set by the launcher, a zero-value indicates

     *    this code should determine this value, using a suitable method or

     *    the line could be omitted.

     *

     * maxHeapSize: in bytes, as set by the launcher, a zero-value indicates

     *    this code should determine this value, using a suitable method.

     *

     * stackSize: in bytes, as set by the launcher, a zero-value indicates

     *    this code determine this value, using a suitable method or omit the

     *    line entirely.

     */

    static void showSettings(boolean printToStderr, String optionFlag,

            long initialHeapSize, long maxHeapSize, long stackSize,

            boolean isServer) {

        PrintStream ostream = (printToStderr) ? System.err : System.out;

        String opts[] = optionFlag.split(":");

        String optStr = (opts.length > 1 && opts[1] != null)

                ? opts[1].trim()

                : "all";

        switch (optStr) {

            case "vm":

                printVmSettings(ostream, initialHeapSize, maxHeapSize,

                        stackSize, isServer);

                break;

            case "properties":

                printProperties(ostream);

                break;

            case "locale":

                printLocale(ostream);

                break;

            default:

                printVmSettings(ostream, initialHeapSize, maxHeapSize,

                        stackSize, isServer);

                printProperties(ostream);

                printLocale(ostream);

                break;

        }

    }

    /*

     * prints the main vm settings subopt/section

     */

    private static void printVmSettings(PrintStream ostream,

            long initialHeapSize, long maxHeapSize,

            long stackSize, boolean isServer) {

        ostream.println(VM_SETTINGS);

        if (stackSize != 0L) {

            ostream.println(INDENT + "Stack Size: " +

                    SizePrefix.scaleValue(stackSize));

        }

        if (initialHeapSize != 0L) {

             ostream.println(INDENT + "Min. Heap Size: " +

                    SizePrefix.scaleValue(initialHeapSize));

        }

        if (maxHeapSize != 0L) {

            ostream.println(INDENT + "Max. Heap Size: " +

                    SizePrefix.scaleValue(maxHeapSize));

        } else {

            ostream.println(INDENT + "Max. Heap Size (Estimated): "

                    + SizePrefix.scaleValue(Runtime.getRuntime().maxMemory()));

        }

        ostream.println(INDENT + "Ergonomics Machine Class: "

                + ((isServer) ? "server" : "client"));

        ostream.println(INDENT + "Using VM: "

                + System.getProperty("java.vm.name"));

        ostream.println();

    }

    /*

     * prints the properties subopt/section

     */

    private static void printProperties(PrintStream ostream) {

        Properties p = System.getProperties();

        ostream.println(PROP_SETTINGS);

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

        sortedPropertyKeys.addAll(p.stringPropertyNames());

        Collections.sort(sortedPropertyKeys);

        for (String x : sortedPropertyKeys) {

            printPropertyValue(ostream, x, p.getProperty(x));

        }

        ostream.println();

    }

    private static boolean isPath(String key) {

        return key.endsWith(".dirs") || key.endsWith(".path");

    }

    private static void printPropertyValue(PrintStream ostream,

            String key, String value) {

        ostream.print(INDENT + key + " = ");

        if (key.equals("line.separator")) {

            for (byte b : value.getBytes()) {

                switch (b) {

                    case 0xd:

                        ostream.print("\\r ");

                        break;

                    case 0xa:

                        ostream.print("\\n ");

                        break;

                    default:

                        // print any bizzare line separators in hex, but really

                        // shouldn't happen.

                        ostream.printf("0x%02X", b & 0xff);

                        break;

                }

            }

            ostream.println();

            return;

        }

        if (!isPath(key)) {

            ostream.println(value);

            return;

        }

        String[] values = value.split(System.getProperty("path.separator"));

        boolean first = true;

        for (String s : values) {

            if (first) { // first line treated specially

                ostream.println(s);

                first = false;

            } else { // following lines prefix with indents

                ostream.println(INDENT + INDENT + s);

            }

        }

    }

    /*

     * prints the locale subopt/section

     */

    private static void printLocale(PrintStream ostream) {

        Locale locale = Locale.getDefault();

        ostream.println(LOCALE_SETTINGS);

        ostream.println(INDENT + "default locale = " +

                locale.getDisplayLanguage());

        ostream.println(INDENT + "default display locale = " +

                Locale.getDefault(Category.DISPLAY).getDisplayName());

        ostream.println(INDENT + "default format locale = " +

                Locale.getDefault(Category.FORMAT).getDisplayName());

        printLocales(ostream);

        ostream.println();

    }

    private static void printLocales(PrintStream ostream) {

        Locale[] tlocales = Locale.getAvailableLocales();

        final int len = tlocales == null ? 0 : tlocales.length;

        if (len < 1 ) {

            return;

        }

        // Locale does not implement Comparable so we convert it to String

        // and sort it for pretty printing.

        Set<String> sortedSet = new TreeSet<>();

        for (Locale l : tlocales) {

            sortedSet.add(l.toString());

        }

        ostream.print(INDENT + "available locales = ");

        Iterator<String> iter = sortedSet.iterator();

        final int last = len - 1;

        for (int i = 0 ; iter.hasNext() ; i++) {

            String s = iter.next();

            ostream.print(s);

            if (i != last) {

                ostream.print(", ");

            }

            // print columns of 8

            if ((i + 1) % 8 == 0) {

                ostream.println();

                ostream.print(INDENT + INDENT);

            }

        }

    }

    private enum SizePrefix {

        KILO(1024, "K"),

        MEGA(1024 * 1024, "M"),

        GIGA(1024 * 1024 * 1024, "G"),

        TERA(1024L * 1024L * 1024L * 1024L, "T");

        long size;

        String abbrev;

        SizePrefix(long size, String abbrev) {

            this.size = size;

            this.abbrev = abbrev;

        }

        private static String scale(long v, SizePrefix prefix) {

            return BigDecimal.valueOf(v).divide(BigDecimal.valueOf(prefix.size),

                    2, RoundingMode.HALF_EVEN).toPlainString() + prefix.abbrev;

        }

        /*

         * scale the incoming values to a human readable form, represented as

         * K, M, G and T, see java.c parse_size for the scaled values and

         * suffixes. The lowest possible scaled value is Kilo.

         */

        static String scaleValue(long v) {

            if (v < MEGA.size) {

                return scale(v, KILO);

            } else if (v < GIGA.size) {

                return scale(v, MEGA);

            } else if (v < TERA.size) {

                return scale(v, GIGA);

            } else {

                return scale(v, TERA);

            }

        }

    }

    /**

     * A private helper method to get a localized message and also

     * apply any arguments that we might pass.

     */

    private static String getLocalizedMessage(String key, Object... args) {

        String msg = ResourceBundleHolder.RB.getString(key);

        return (args != null) ? MessageFormat.format(msg, args) : msg;

    }

    /**

     * The java -help message is split into 3 parts, an invariant, followed

     * by a set of platform dependent variant messages, finally an invariant

     * set of lines.

     * This method initializes the help message for the first time, and also

     * assembles the invariant header part of the message.

     */

    static void initHelpMessage(String progname) {

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.header",

                (progname == null) ? "java" : progname ));

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.datamodel",

                32));

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.datamodel",

                64));

    }

    /**

     * Appends the vm selection messages to the header, already created.

     * initHelpSystem must already be called.

     */

    static void appendVmSelectMessage(String vm1, String vm2) {

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.vmselect",

                vm1, vm2));

    }

    /**

     * Appends the vm synoym message to the header, already created.

     * initHelpSystem must be called before using this method.

     */

    static void appendVmSynonymMessage(String vm1, String vm2) {

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.hotspot",

                vm1, vm2));

    }

    /**

     * Appends the vm Ergo message to the header, already created.

     * initHelpSystem must be called before using this method.

     */

    static void appendVmErgoMessage(boolean isServerClass, String vm) {

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.ergo.message1",

                vm));

        outBuf = (isServerClass)

             ? outBuf.append(",\n" +

                getLocalizedMessage("java.launcher.ergo.message2") + "\n\n")

             : outBuf.append(".\n\n");

    }

    /**

     * Appends the last invariant part to the previously created messages,

     * and finishes up the printing to the desired output stream.

     * initHelpSystem must be called before using this method.

     */

    static void printHelpMessage(boolean printToStderr) {

        PrintStream ostream = (printToStderr) ? System.err : System.out;

        outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.footer",

                File.pathSeparator));

        ostream.println(outBuf.toString());

    }

    /**

     * Prints the Xusage text to the desired output stream.

     */

    static void printXUsageMessage(boolean printToStderr) {

        PrintStream ostream =  (printToStderr) ? System.err : System.out;

        ostream.println(getLocalizedMessage("java.launcher.X.usage",

                File.pathSeparator));

    }

    static String getMainClassFromJar(PrintStream ostream, String jarname) {

        try {

            JarFile jarFile = null;

            try {

                jarFile = new JarFile(jarname);

                Manifest manifest = jarFile.getManifest();

                if (manifest == null) {

                    abort(ostream, null, "java.launcher.jar.error2", jarname);

                }

                Attributes mainAttrs = manifest.getMainAttributes();

                if (mainAttrs == null) {

                    abort(ostream, null, "java.launcher.jar.error3", jarname);

                }

                return mainAttrs.getValue(MAIN_CLASS).trim();

            } finally {

                if (jarFile != null) {

                    jarFile.close();

                }

            }

        } catch (IOException ioe) {

            abort(ostream, ioe, "java.launcher.jar.error1", jarname);

        }

        return null;

    }

    // From src/share/bin/java.c:

    //   enum LaunchMode { LM_UNKNOWN = 0, LM_CLASS, LM_JAR };

    private static final int LM_UNKNOWN = 0;

    private static final int LM_CLASS   = 1;

    private static final int LM_JAR     = 2;

    static void abort(PrintStream ostream, Throwable t, String msgKey, Object... args) {

        if (msgKey != null) {

            ostream.println(getLocalizedMessage(msgKey, args));

        }

        if (sun.misc.VM.getSavedProperty(diagprop) != null) {

            if (t != null) {

                t.printStackTrace();

            } else {

                Thread.currentThread().dumpStack();

            }

        }

        System.exit(1);

    }

    /**

     * This method does the following:

     * 1. gets the classname from a Jar's manifest, if necessary

     * 2. loads the class using the System ClassLoader

     * 3. ensures the availability and accessibility of the main method,

     *    using signatureDiagnostic method.

     *    a. does the class exist

     *    b. is there a main

     *    c. is the main public

     *    d. is the main static

     *    c. does the main take a String array for args

     * 4. and off we go......

     *

     * @param printToStderr

     * @param isJar

     * @param name

     * @return

     */

    public static Class<?> checkAndLoadMain(boolean printToStderr,

                                            int mode,

                                            String what) {

        final PrintStream ostream = (printToStderr) ? System.err : System.out;

        final ClassLoader ld = ClassLoader.getSystemClassLoader();

        // get the class name

        String cn = null;

        switch (mode) {

            case LM_CLASS:

                cn = what;

                break;

            case LM_JAR:

                cn = getMainClassFromJar(ostream, what);

                break;

            default:

                // should never happen

                throw new InternalError("" + mode + ": Unknown launch mode");

        }

        cn = cn.replace('/', '.');

        Class<?> c = null;

        try {

            c = ld.loadClass(cn);

        } catch (ClassNotFoundException cnfe) {

            abort(ostream, cnfe, "java.launcher.cls.error1", cn);

        }

        getMainMethod(ostream, c);

        return c;

    }

    static Method getMainMethod(PrintStream ostream, Class<?> clazz) {

        String classname = clazz.getName();

        Method method = null;

        try {

            method = clazz.getMethod("main", String[].class);

        } catch (NoSuchMethodException nsme) {

            abort(ostream, null, "java.launcher.cls.error4", classname);

        }

        /*

         * getMethod (above) will choose the correct method, based

         * on its name and parameter type, however, we still have to

         * ensure that the method is static and returns a void.

         */

        int mod = method.getModifiers();

        if (!Modifier.isStatic(mod)) {

            abort(ostream, null, "java.launcher.cls.error2", "static", classname);

        }

        if (method.getReturnType() != java.lang.Void.TYPE) {

            abort(ostream, null, "java.launcher.cls.error3", classname);

        }