/*

 * 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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

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

import com.sun.jdi.*;

import com.sun.jdi.event.*;

import com.sun.jdi.request.EventRequestManager;

import com.sun.jdi.request.EventRequest;

import java.io.PrintStream;

import java.util.StringTokenizer;

import java.util.Collection;

import java.util.Iterator;

public class EventHandler implements Runnable {

    EventNotifier notifier;

    Thread thread;

    volatile boolean connected = true;

    boolean completed = false;

    String shutdownMessageKey;

    boolean stopOnVMStart;

    EventHandler(EventNotifier notifier, boolean stopOnVMStart) {

        this.notifier = notifier;

        this.stopOnVMStart = stopOnVMStart;

        this.thread = new Thread(this, "event-handler");

        this.thread.start();

    }

    synchronized void shutdown() {

        connected = false;  // force run() loop termination

        thread.interrupt();

        while (!completed) {

            try {wait();} catch (InterruptedException exc) {}

        }

    }

    public void run() {

        EventQueue queue = Env.vm().eventQueue();

        while (connected) {

            try {

                EventSet eventSet = queue.remove();

                boolean resumeStoppedApp = false;

                EventIterator it = eventSet.eventIterator();

                while (it.hasNext()) {

                    resumeStoppedApp |= !handleEvent(it.nextEvent());

                }

                if (resumeStoppedApp) {

                    eventSet.resume();

                } else if (eventSet.suspendPolicy() == EventRequest.SUSPEND_ALL) {

                    setCurrentThread(eventSet);

                    notifier.vmInterrupted();

                }

            } catch (InterruptedException exc) {

                // Do nothing. Any changes will be seen at top of loop.

            } catch (VMDisconnectedException discExc) {

                handleDisconnectedException();

                break;

            }

        }

        synchronized (this) {

            completed = true;

            notifyAll();

        }

    }

    private boolean handleEvent(Event event) {

        notifier.receivedEvent(event);

        if (event instanceof ExceptionEvent) {

            return exceptionEvent(event);

        } else if (event instanceof BreakpointEvent) {

            return breakpointEvent(event);

        } else if (event instanceof WatchpointEvent) {

            return fieldWatchEvent(event);

        } else if (event instanceof StepEvent) {

            return stepEvent(event);

        } else if (event instanceof MethodEntryEvent) {

            return methodEntryEvent(event);

        } else if (event instanceof MethodExitEvent) {

            return methodExitEvent(event);

        } else if (event instanceof ClassPrepareEvent) {

            return classPrepareEvent(event);

        } else if (event instanceof ClassUnloadEvent) {

            return classUnloadEvent(event);

        } else if (event instanceof ThreadStartEvent) {

            return threadStartEvent(event);

        } else if (event instanceof ThreadDeathEvent) {

            return threadDeathEvent(event);

        } else if (event instanceof VMStartEvent) {

            return vmStartEvent(event);

        } else {

            return handleExitEvent(event);

        }

    }

    private boolean vmDied = false;

    private boolean handleExitEvent(Event event) {

        if (event instanceof VMDeathEvent) {

            vmDied = true;

            return vmDeathEvent(event);

        } else if (event instanceof VMDisconnectEvent) {

            connected = false;

            if (!vmDied) {

                vmDisconnectEvent(event);

            }

            Env.shutdown(shutdownMessageKey);

            return false;

        } else {

            throw new InternalError(MessageOutput.format("Unexpected event type",

                                                         new Object[] {event.getClass()}));

        }

    }

    synchronized void handleDisconnectedException() {

        /*

         * A VMDisconnectedException has happened while dealing with

         * another event. We need to flush the event queue, dealing only

         * with exit events (VMDeath, VMDisconnect) so that we terminate

         * correctly.

         */

        EventQueue queue = Env.vm().eventQueue();

        while (connected) {

            try {

                EventSet eventSet = queue.remove();

                EventIterator iter = eventSet.eventIterator();

                while (iter.hasNext()) {

                    handleExitEvent(iter.next());

                }

            } catch (InterruptedException exc) {

                // ignore

            } catch (InternalError exc) {

                // ignore

            }

        }

    }

    private ThreadReference eventThread(Event event) {

        if (event instanceof ClassPrepareEvent) {

            return ((ClassPrepareEvent)event).thread();

        } else if (event instanceof LocatableEvent) {

            return ((LocatableEvent)event).thread();

        } else if (event instanceof ThreadStartEvent) {

            return ((ThreadStartEvent)event).thread();

        } else if (event instanceof ThreadDeathEvent) {

            return ((ThreadDeathEvent)event).thread();

        } else if (event instanceof VMStartEvent) {

            return ((VMStartEvent)event).thread();

        } else {

            return null;

        }

    }

    private void setCurrentThread(EventSet set) {

        ThreadReference thread;

        if (set.size() > 0) {

            /*

             * If any event in the set has a thread associated with it,

             * they all will, so just grab the first one.

             */

            Event event = set.iterator().next(); // Is there a better way?

            thread = eventThread(event);

        } else {

            thread = null;

        }

        setCurrentThread(thread);

    }

    private void setCurrentThread(ThreadReference thread) {

        ThreadInfo.invalidateAll();

        ThreadInfo.setCurrentThread(thread);

    }

    private boolean vmStartEvent(Event event)  {

        VMStartEvent se = (VMStartEvent)event;

        notifier.vmStartEvent(se);

        return stopOnVMStart;

    }

    private boolean breakpointEvent(Event event)  {

        BreakpointEvent be = (BreakpointEvent)event;

        notifier.breakpointEvent(be);

        return true;

    }

    private boolean methodEntryEvent(Event event)  {

        MethodEntryEvent me = (MethodEntryEvent)event;

        notifier.methodEntryEvent(me);

        return true;

    }

    private boolean methodExitEvent(Event event)  {

        MethodExitEvent me = (MethodExitEvent)event;

        return notifier.methodExitEvent(me);

    }

    private boolean fieldWatchEvent(Event event)  {

        WatchpointEvent fwe = (WatchpointEvent)event;

        notifier.fieldWatchEvent(fwe);

        return true;

    }

    private boolean stepEvent(Event event)  {

        StepEvent se = (StepEvent)event;

        notifier.stepEvent(se);

        return true;

    }

    private boolean classPrepareEvent(Event event)  {

        ClassPrepareEvent cle = (ClassPrepareEvent)event;

        notifier.classPrepareEvent(cle);

        if (!Env.specList.resolve(cle)) {

            MessageOutput.lnprint("Stopping due to deferred breakpoint errors.");

            return true;

        } else {

            return false;

        }

    }

    private boolean classUnloadEvent(Event event)  {

        ClassUnloadEvent cue = (ClassUnloadEvent)event;

        notifier.classUnloadEvent(cue);

        return false;

    }

    private boolean exceptionEvent(Event event) {

        ExceptionEvent ee = (ExceptionEvent)event;

        notifier.exceptionEvent(ee);

        return true;

    }

    private boolean threadDeathEvent(Event event) {

        ThreadDeathEvent tee = (ThreadDeathEvent)event;

        ThreadInfo.removeThread(tee.thread());

        return false;

    }

    private boolean threadStartEvent(Event event) {

        ThreadStartEvent tse = (ThreadStartEvent)event;

        ThreadInfo.addThread(tse.thread());

        notifier.threadStartEvent(tse);

        return false;

    }

    public boolean vmDeathEvent(Event event) {

        shutdownMessageKey = "The application exited";

        notifier.vmDeathEvent((VMDeathEvent)event);

        return false;

    }

    public boolean vmDisconnectEvent(Event event) {

        shutdownMessageKey = "The application has been disconnected";

        notifier.vmDisconnectEvent((VMDisconnectEvent)event);

        return false;

    }

}