/*

 * Copyright (c) 1998, 2019, 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.

 */

/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

package com.sun.tools.example.debug.tty;

import com.sun.jdi.*;

import com.sun.jdi.event.*;

import com.sun.jdi.request.*;

import com.sun.jdi.connect.*;

import java.util.*;

import java.io.*;

public class TTY implements EventNotifier {

    EventHandler handler = null;

    /**

     * List of Strings to execute at each stop.

     */

    private List<String> monitorCommands = new ArrayList<String>();

    private int monitorCount = 0;

    /**

     * The name of this tool.

     */

    private static final String progname = "jdb";

    private volatile boolean shuttingDown = false;

    public void setShuttingDown(boolean s) {

       shuttingDown = s;

    }

    public boolean isShuttingDown() {

        return shuttingDown;

    }

    @Override

    public void vmStartEvent(VMStartEvent se)  {

        Thread.yield();  // fetch output

        MessageOutput.lnprint("VM Started:");

    }

    @Override

    public void vmDeathEvent(VMDeathEvent e)  {

    }

    @Override

    public void vmDisconnectEvent(VMDisconnectEvent e)  {

    }

    @Override

    public void threadStartEvent(ThreadStartEvent e)  {

    }

    @Override

    public void threadDeathEvent(ThreadDeathEvent e)  {

    }

    @Override

    public void classPrepareEvent(ClassPrepareEvent e)  {

    }

    @Override

    public void classUnloadEvent(ClassUnloadEvent e)  {

    }

    @Override

    public void breakpointEvent(BreakpointEvent be)  {

        Thread.yield();  // fetch output

        MessageOutput.lnprint("Breakpoint hit:");

        // Print breakpoint location and prompt if suspend policy is

        // SUSPEND_NONE or SUSPEND_EVENT_THREAD. In case of SUSPEND_ALL

        // policy this is handled by vmInterrupted() method.

        int suspendPolicy = be.request().suspendPolicy();

        switch (suspendPolicy) {

            case EventRequest.SUSPEND_EVENT_THREAD:

            case EventRequest.SUSPEND_NONE:

                printBreakpointLocation(be);

                MessageOutput.printPrompt();

                break;

        }

    }

    @Override

    public void fieldWatchEvent(WatchpointEvent fwe)  {

        Field field = fwe.field();

        ObjectReference obj = fwe.object();

        Thread.yield();  // fetch output

        if (fwe instanceof ModificationWatchpointEvent) {

            MessageOutput.lnprint("Field access encountered before after",

                                  new Object [] {field,

                                                 fwe.valueCurrent(),

                                                 ((ModificationWatchpointEvent)fwe).valueToBe()});

        } else {

            MessageOutput.lnprint("Field access encountered", field.toString());

        }

    }

    @Override

    public void stepEvent(StepEvent se)  {

        Thread.yield();  // fetch output

        MessageOutput.lnprint("Step completed:");

    }

    @Override

    public void exceptionEvent(ExceptionEvent ee) {

        Thread.yield();  // fetch output

        Location catchLocation = ee.catchLocation();

        if (catchLocation == null) {

            MessageOutput.lnprint("Exception occurred uncaught",

                                  ee.exception().referenceType().name());

        } else {

            MessageOutput.lnprint("Exception occurred caught",

                                  new Object [] {ee.exception().referenceType().name(),

                                                 Commands.locationString(catchLocation)});

        }

    }

    @Override

    public void methodEntryEvent(MethodEntryEvent me) {

        Thread.yield();  // fetch output

        /*

         * These can be very numerous, so be as efficient as possible.

         * If we are stopping here, then we will see the normal location

         * info printed.

         */

        if (me.request().suspendPolicy() != EventRequest.SUSPEND_NONE) {

            // We are stopping; the name will be shown by the normal mechanism

            MessageOutput.lnprint("Method entered:");

        } else {

            // We aren't stopping, show the name

            MessageOutput.print("Method entered:");

            printLocationOfEvent(me);

        }

    }

    @Override

    public boolean methodExitEvent(MethodExitEvent me) {

        Thread.yield();  // fetch output

        /*

         * These can be very numerous, so be as efficient as possible.

         */

        Method mmm = Env.atExitMethod();

        Method meMethod = me.method();

        if (mmm == null || mmm.equals(meMethod)) {

            // Either we are not tracing a specific method, or we are

            // and we are exitting that method.

            if (me.request().suspendPolicy() != EventRequest.SUSPEND_NONE) {

                // We will be stopping here, so do a newline

                MessageOutput.println();

            }

            if (Env.vm().canGetMethodReturnValues()) {

                MessageOutput.print("Method exitedValue:", me.returnValue() + "");

            } else {

                MessageOutput.print("Method exited:");

            }

            if (me.request().suspendPolicy() == EventRequest.SUSPEND_NONE) {

                // We won't be stopping here, so show the method name

                printLocationOfEvent(me);

            }

            // In case we want to have a one shot trace exit some day, this

            // code disables the request so we don't hit it again.

            if (false) {

                // This is a one shot deal; we don't want to stop

                // here the next time.

                Env.setAtExitMethod(null);

                EventRequestManager erm = Env.vm().eventRequestManager();

                for (EventRequest eReq : erm.methodExitRequests()) {

                    if (eReq.equals(me.request())) {

                        eReq.disable();

                    }

                }

            }

            return true;

        }

        // We are tracing a specific method, and this isn't it.  Keep going.

        return false;

    }

    @Override

    public void vmInterrupted() {

        Thread.yield();  // fetch output

        printCurrentLocation();

        for (String cmd : monitorCommands) {

            StringTokenizer t = new StringTokenizer(cmd);

            t.nextToken();  // get rid of monitor number

            executeCommand(t);

        }

        MessageOutput.printPrompt();

    }

    @Override

    public void receivedEvent(Event event) {

    }

    private void printBaseLocation(String threadName, Location loc) {

        MessageOutput.println("location",

                              new Object [] {threadName,

                                             Commands.locationString(loc)});

    }

    private void printBreakpointLocation(BreakpointEvent be) {

        printLocationWithSourceLine(be.thread().name(), be.location());

    }

    private void printCurrentLocation() {

        ThreadInfo threadInfo = ThreadInfo.getCurrentThreadInfo();

        StackFrame frame;

        try {

            frame = threadInfo.getCurrentFrame();

        } catch (IncompatibleThreadStateException exc) {

            MessageOutput.println("<location unavailable>");

            return;

        }

        if (frame == null) {

            MessageOutput.println("No frames on the current call stack");

        } else {

            printLocationWithSourceLine(threadInfo.getThread().name(), frame.location());

        }

        MessageOutput.println();

    }

    private void printLocationWithSourceLine(String threadName, Location loc) {

        printBaseLocation(threadName, loc);

        // Output the current source line, if possible

        if (loc.lineNumber() != -1) {

            String line;

            try {

                line = Env.sourceLine(loc, loc.lineNumber());

            } catch (java.io.IOException e) {

                line = null;

            }

            if (line != null) {

                MessageOutput.println("source line number and line",

                                           new Object [] {loc.lineNumber(),

                                                          line});

            }

        }

    }

    private void printLocationOfEvent(LocatableEvent theEvent) {

        printBaseLocation(theEvent.thread().name(), theEvent.location());

    }

    void help() {

        MessageOutput.println("zz help text");

    }

    private static final String[][] commandList = {

        /*

         * NOTE: this list must be kept sorted in ascending ASCII

         *       order by element [0].  Ref: isCommand() below.

         *

         *Command      OK when        OK when

         * name      disconnected?   readonly?

         *------------------------------------

         */

        {"!!",           "n",         "y"},

        {"?",            "y",         "y"},

        {"bytecodes",    "n",         "y"},

        {"catch",        "y",         "n"},

        {"class",        "n",         "y"},

        {"classes",      "n",         "y"},

        {"classpath",    "n",         "y"},

        {"clear",        "y",         "n"},

        {"connectors",   "y",         "y"},

        {"cont",         "n",         "n"},

        {"dbgtrace",     "y",         "y"},

        {"disablegc",    "n",         "n"},

        {"down",         "n",         "y"},

        {"dump",         "n",         "y"},

        {"enablegc",     "n",         "n"},

        {"eval",         "n",         "y"},

        {"exclude",      "y",         "n"},

        {"exit",         "y",         "y"},

        {"extension",    "n",         "y"},

        {"fields",       "n",         "y"},

        {"gc",           "n",         "n"},

        {"help",         "y",         "y"},

        {"ignore",       "y",         "n"},

        {"interrupt",    "n",         "n"},

        {"kill",         "n",         "n"},

        {"lines",        "n",         "y"},

        {"list",         "n",         "y"},

        {"load",         "n",         "y"},

        {"locals",       "n",         "y"},

        {"lock",         "n",         "n"},

        {"memory",       "n",         "y"},

        {"methods",      "n",         "y"},

        {"monitor",      "n",         "n"},

        {"next",         "n",         "n"},

        {"pop",          "n",         "n"},

        {"print",        "n",         "y"},

        {"quit",         "y",         "y"},

        {"read",         "y",         "y"},

        {"redefine",     "n",         "n"},

        {"reenter",      "n",         "n"},

        {"resume",       "n",         "n"},

        {"run",          "y",         "n"},

        {"save",         "n",         "n"},

        {"set",          "n",         "n"},

        {"sourcepath",   "y",         "y"},

        {"step",         "n",         "n"},

        {"stepi",        "n",         "n"},

        {"stop",         "y",         "n"},

        {"suspend",      "n",         "n"},

        {"thread",       "n",         "y"},

        {"threadgroup",  "n",         "y"},

        {"threadgroups", "n",         "y"},

        {"threadlocks",  "n",         "y"},

        {"threads",      "n",         "y"},

        {"trace",        "n",         "n"},

        {"unmonitor",    "n",         "n"},

        {"untrace",      "n",         "n"},

        {"unwatch",      "y",         "n"},

        {"up",           "n",         "y"},

        {"use",          "y",         "y"},

        {"version",      "y",         "y"},

        {"watch",        "y",         "n"},

        {"where",        "n",         "y"},

        {"wherei",       "n",         "y"},

    };

    /*

     * Look up the command string in commandList.

     * If found, return the index.

     * If not found, return index < 0

     */

    private int isCommand(String key) {

        //Reference: binarySearch() in java/util/Arrays.java

        //           Adapted for use with String[][0].

        int low = 0;

        int high = commandList.length - 1;

        while (low <= high) {

            int mid = (low + high) >>> 1;

            String midVal = commandList[mid][0];

            int compare = midVal.compareTo(key);

            if (compare < 0) {

                low = mid + 1;

            } else if (compare > 0) {

                high = mid - 1;

            }

            else {

                return mid; // key found

        }

        }

        return -(low + 1);  // key not found.

    };

    /*

     * Return true if the command is OK when disconnected.

     */

    private boolean isDisconnectCmd(int ii) {

        if (ii < 0 || ii >= commandList.length) {

            return false;

        }

        return (commandList[ii][1].equals("y"));

    }

    /*

     * Return true if the command is OK when readonly.

     */

    private boolean isReadOnlyCmd(int ii) {

        if (ii < 0 || ii >= commandList.length) {

            return false;

        }

        return (commandList[ii][2].equals("y"));

    };

    void executeCommand(StringTokenizer t) {

        String cmd = t.nextToken().toLowerCase();

        // Normally, prompt for the next command after this one is done

        boolean showPrompt = true;

        /*

         * Anything starting with # is discarded as a no-op or 'comment'.

         */

        if (!cmd.startsWith("#")) {

            /*

             * Next check for an integer repetition prefix.  If found,

             * recursively execute cmd that number of times.

             */

            if (Character.isDigit(cmd.charAt(0)) && t.hasMoreTokens()) {

                try {

                    int repeat = Integer.parseInt(cmd);

                    String subcom = t.nextToken("");

                    while (repeat-- > 0) {

                        executeCommand(new StringTokenizer(subcom));

                        showPrompt = false; // Bypass the printPrompt() below.

                    }

                } catch (NumberFormatException exc) {

                    MessageOutput.println("Unrecognized command.  Try help...", cmd);

                }

            } else {

                int commandNumber = isCommand(cmd);

                /*

                 * Check for an unknown command

                 */

                if (commandNumber < 0) {

                    MessageOutput.println("Unrecognized command.  Try help...", cmd);

                } else if (!Env.connection().isOpen() && !isDisconnectCmd(commandNumber)) {

                    MessageOutput.println("Command not valid until the VM is started with the run command",

                                          cmd);

                } else if (Env.connection().isOpen() && !Env.vm().canBeModified() &&

                           !isReadOnlyCmd(commandNumber)) {

                    MessageOutput.println("Command is not supported on a read-only VM connection",

                                          cmd);

                } else {

                    Commands evaluator = new Commands();

                    try {

                        if (cmd.equals("print")) {

                            evaluator.commandPrint(t, false);

                            showPrompt = false;        // asynchronous command

                        } else if (cmd.equals("eval")) {

                            evaluator.commandPrint(t, false);

                            showPrompt = false;        // asynchronous command

                        } else if (cmd.equals("set")) {

                            evaluator.commandSet(t);

                            showPrompt = false;        // asynchronous command

                        } else if (cmd.equals("dump")) {

                            evaluator.commandPrint(t, true);

                            showPrompt = false;        // asynchronous command

                        } else if (cmd.equals("locals")) {

                            evaluator.commandLocals();

                        } else if (cmd.equals("classes")) {

                            evaluator.commandClasses();

                        } else if (cmd.equals("class")) {

                            evaluator.commandClass(t);

                        } else if (cmd.equals("connectors")) {

                            evaluator.commandConnectors(Bootstrap.virtualMachineManager());

                        } else if (cmd.equals("methods")) {

                            evaluator.commandMethods(t);

                        } else if (cmd.equals("fields")) {

                            evaluator.commandFields(t);

                        } else if (cmd.equals("threads")) {

                            evaluator.commandThreads(t);

                        } else if (cmd.equals("thread")) {

                            evaluator.commandThread(t);

                        } else if (cmd.equals("suspend")) {

                            evaluator.commandSuspend(t);

                        } else if (cmd.equals("resume")) {

                            evaluator.commandResume(t);

                        } else if (cmd.equals("cont")) {

                            MessageOutput.printPrompt(true);

                            showPrompt = false;

                            evaluator.commandCont();

                        } else if (cmd.equals("threadgroups")) {

                            evaluator.commandThreadGroups();

                        } else if (cmd.equals("threadgroup")) {

                            evaluator.commandThreadGroup(t);

                        } else if (cmd.equals("catch")) {

                            evaluator.commandCatchException(t);

                        } else if (cmd.equals("ignore")) {

                            evaluator.commandIgnoreException(t);

                        } else if (cmd.equals("step")) {

                            MessageOutput.printPrompt(true);

                            showPrompt = false;

                            evaluator.commandStep(t);

                        } else if (cmd.equals("stepi")) {

                            MessageOutput.printPrompt(true);

                            showPrompt = false;

                            evaluator.commandStepi();

                        } else if (cmd.equals("next")) {

                            MessageOutput.printPrompt(true);

                            showPrompt = false;

                            evaluator.commandNext();

                        } else if (cmd.equals("kill")) {

                            showPrompt = false;        // asynchronous command

                            evaluator.commandKill(t);

                        } else if (cmd.equals("interrupt")) {

                            evaluator.commandInterrupt(t);

                        } else if (cmd.equals("trace")) {

                            evaluator.commandTrace(t);

                        } else if (cmd.equals("untrace")) {

                            evaluator.commandUntrace(t);