/*

 * Copyright (c) 2006, 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 sun.tools.jinfo;

import java.io.IOException;

import java.io.InputStream;

import java.util.Collection;

import com.sun.tools.attach.VirtualMachine;

import com.sun.tools.attach.VirtualMachineDescriptor;

import sun.tools.attach.HotSpotVirtualMachine;

import sun.tools.common.ProcessArgumentMatcher;

/*

 * This class is the main class for the JInfo utility. It parses its arguments

 * and decides if the command should be satisfied using the VM attach mechanism

 * or an SA tool.

 */

final public class JInfo {

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

        if (args.length == 0) {

            usage(1); // no arguments

        }

        checkForUnsupportedOptions(args);

        boolean doFlag = false;

        boolean doFlags = false;

        boolean doSysprops = false;

        int flag = -1;

        // Parse the options (arguments starting with "-" )

        int optionCount = 0;

        while (optionCount < args.length) {

            String arg = args[optionCount];

            if (!arg.startsWith("-")) {

                break;

            }

            optionCount++;

            if (arg.equals("-?") ||

                arg.equals("-h") ||

                arg.equals("--help") ||

                // -help: legacy.

                arg.equals("-help")) {

                usage(0);

            }

            if (arg.equals("-flag")) {

                doFlag = true;

                // Consume the flag

                if (optionCount < args.length) {

                    flag = optionCount++;

                    break;

                }

                usage(1);

            }

            if (arg.equals("-flags")) {

                doFlags = true;

                break;

            }

            if (arg.equals("-sysprops")) {

                doSysprops = true;

                break;

            }

        }

        int paramCount = args.length - optionCount;

        if (paramCount != 1) {

            usage(1);

        }

        String parg = args[optionCount];

        ProcessArgumentMatcher ap = new ProcessArgumentMatcher(parg);

        Collection<String> pids = ap.getVirtualMachinePids(JInfo.class);

        if (pids.isEmpty()) {

            System.err.println("Could not find any processes matching : '" + parg + "'");

            System.exit(1);

        }

        for (String pid : pids) {

            if (pids.size() > 1) {

                System.out.println("Pid:" + pid);

            }

            if (!doFlag && !doFlags && !doSysprops) {

                // Print flags and sysporps if no options given

                sysprops(pid);

                System.out.println();

                flags(pid);

                System.out.println();

                commandLine(pid);

            }

            if (doFlag) {

                if (flag < 0) {

                    System.err.println("Missing flag");

                    usage(1);

                }

                flag(pid, args[flag]);

            }

            if (doFlags) {

                flags(pid);

            }

            if (doSysprops) {

                sysprops(pid);

            }

        }

    }

    private static void flag(String pid, String option) throws IOException {

        HotSpotVirtualMachine vm = (HotSpotVirtualMachine) attach(pid);

        String flag;

        InputStream in;

        int index = option.indexOf('=');

        if (index != -1) {

            flag = option.substring(0, index);

            String value = option.substring(index + 1);

            in = vm.setFlag(flag, value);

        } else {

            char c = option.charAt(0);

            switch (c) {

                case '+':

                    flag = option.substring(1);

                    in = vm.setFlag(flag, "1");

                    break;

                case '-':

                    flag = option.substring(1);

                    in = vm.setFlag(flag, "0");

                    break;

                default:

                    flag = option;

                    in = vm.printFlag(flag);

                    break;

            }

        }

        drain(vm, in);

    }

    private static void flags(String pid) throws IOException {

        HotSpotVirtualMachine vm = (HotSpotVirtualMachine) attach(pid);

        InputStream in = vm.executeJCmd("VM.flags");

        System.out.println("VM Flags:");

        drain(vm, in);

    }

    private static void commandLine(String pid) throws IOException {

        HotSpotVirtualMachine vm = (HotSpotVirtualMachine) attach(pid);

        InputStream in = vm.executeJCmd("VM.command_line");

        drain(vm, in);

    }

    private static void sysprops(String pid) throws IOException {

        HotSpotVirtualMachine vm = (HotSpotVirtualMachine) attach(pid);

        InputStream in = vm.executeJCmd("VM.system_properties");

        System.out.println("Java System Properties:");

        drain(vm, in);

    }

    // Attach to <pid>, exiting if we fail to attach

    private static VirtualMachine attach(String pid) {

        try {

            return VirtualMachine.attach(pid);

        } catch (Exception x) {

            String msg = x.getMessage();

            if (msg != null) {

                System.err.println(pid + ": " + msg);

            } else {

                x.printStackTrace();

            }

            System.exit(1);

            return null; // keep compiler happy

        }

    }

    // Read the stream from the target VM until EOF, then detach

    private static void drain(VirtualMachine vm, InputStream in) throws IOException {

        // read to EOF and just print output

        byte b[] = new byte[256];

        int n;

        do {

            n = in.read(b);

            if (n > 0) {

                String s = new String(b, 0, n, "UTF-8");

                System.out.print(s);

            }

        } while (n > 0);

        in.close();

        vm.detach();

    }

    private static void checkForUnsupportedOptions(String[] args) {

        // Check arguments for -F, and non-numeric value

        // and warn the user that SA is not supported anymore

        int maxCount = 1;

        int paramCount = 0;

        for (String s : args) {

            if (s.equals("-F")) {

                SAOptionError("-F option used");

            }

            if (s.equals("-flag")) {

                maxCount = 2;

            }

            if (! s.startsWith("-")) {

                paramCount += 1;

            }

        }

        if (paramCount > maxCount) {

            SAOptionError("More than " + maxCount + " non-option argument");

        }

    }

    private static void SAOptionError(String msg) {

        System.err.println("Error: " + msg);

        System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jinfo instead");

        System.exit(1);

    }

     // print usage message

    private static void usage(int exit) {

        System.err.println("Usage:");

        System.err.println("    jinfo <option> <pid>");

        System.err.println("       (to connect to a running process)");

        System.err.println("");

        System.err.println("where <option> is one of:");

        System.err.println("    -flag <name>         to print the value of the named VM flag");

        System.err.println("    -flag [+|-]<name>    to enable or disable the named VM flag");

        System.err.println("    -flag <name>=<value> to set the named VM flag to the given value");

        System.err.println("    -flags               to print VM flags");

        System.err.println("    -sysprops            to print Java system properties");

        System.err.println("    <no option>          to print both VM flags and system properties");

        System.err.println("    -? | -h | --help | -help to print this help message");

        System.exit(exit);

    }

}