/*

 * 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.connect.*;

import com.sun.jdi.request.EventRequestManager;

import com.sun.jdi.request.ExceptionRequest;

import com.sun.jdi.request.ThreadStartRequest;

import com.sun.jdi.request.ThreadDeathRequest;

import java.util.*;

import java.util.regex.*;

import java.io.*;

class VMConnection {

    private VirtualMachine vm;

    private Process process = null;

    private int outputCompleteCount = 0;

    private final Connector connector;

    private final Map<String, com.sun.jdi.connect.Connector.Argument> connectorArgs;

    private final int traceFlags;

    synchronized void notifyOutputComplete() {

        outputCompleteCount++;

        notifyAll();

    }

    synchronized void waitOutputComplete() {

        // Wait for stderr and stdout

        if (process != null) {

            while (outputCompleteCount < 2) {

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

            }

        }

    }

    private Connector findConnector(String name) {

        for (Connector connector :

                 Bootstrap.virtualMachineManager().allConnectors()) {

            if (connector.name().equals(name)) {

                return connector;

            }

        }

        return null;

    }

    private Map <String, com.sun.jdi.connect.Connector.Argument> parseConnectorArgs(Connector connector, String argString) {

        Map<String, com.sun.jdi.connect.Connector.Argument> arguments = connector.defaultArguments();

        /*

         * We are parsing strings of the form:

         *    name1=value1,[name2=value2,...]

         * However, the value1...valuen substrings may contain

         * embedded comma(s), so make provision for quoting inside

         * the value substrings. (Bug ID 4285874)

         */

        String regexPattern =

            "(quote=[^,]+,)|" +           // special case for quote=.,

            "(\\w+=)" +                   // name=

            "(((\"[^\"]*\")|" +           //   ( "l , ue"

            "('[^']*')|" +                //     'l , ue'

            "([^,'\"]+))+,)";             //     v a l u e )+ ,

        Pattern p = Pattern.compile(regexPattern);

        Matcher m = p.matcher(argString);

        while (m.find()) {

            int startPosition = m.start();

            int endPosition = m.end();

            if (startPosition > 0) {

                /*

                 * It is an error if parsing skips over any part of argString.

                 */

                throw new IllegalArgumentException

                    (MessageOutput.format("Illegal connector argument",

                                          argString));

            }

            String token = argString.substring(startPosition, endPosition);

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

            String name = token.substring(0, index);

            String value = token.substring(index + 1,

                                           token.length() - 1); // Remove comma delimiter

            Connector.Argument argument = arguments.get(name);

            if (argument == null) {

                throw new IllegalArgumentException

                    (MessageOutput.format("Argument is not defined for connector:",

                                          new Object [] {name, connector.name()}));

            }

            argument.setValue(value);

            argString = argString.substring(endPosition); // Remove what was just parsed...

            m = p.matcher(argString);                     //    and parse again on what is left.

        }

        if ((! argString.equals(",")) && (argString.length() > 0)) {

            /*

             * It is an error if any part of argString is left over,

             * unless it was empty to begin with.

             */

            throw new IllegalArgumentException

                (MessageOutput.format("Illegal connector argument", argString));

        }

        return arguments;

    }

    VMConnection(String connectSpec, int traceFlags) {

        String nameString;

        String argString;

        int index = connectSpec.indexOf(':');

        if (index == -1) {

            nameString = connectSpec;

            argString = "";

        } else {

            nameString = connectSpec.substring(0, index);

            argString = connectSpec.substring(index + 1);

        }

        connector = findConnector(nameString);

        if (connector == null) {

            throw new IllegalArgumentException

                (MessageOutput.format("No connector named:", nameString));

        }

        connectorArgs = parseConnectorArgs(connector, argString);

        this.traceFlags = traceFlags;

    }

    synchronized VirtualMachine open() {

        if (connector instanceof LaunchingConnector) {

            vm = launchTarget();

        } else if (connector instanceof AttachingConnector) {

            vm = attachTarget();

        } else if (connector instanceof ListeningConnector) {

            vm = listenTarget();

        } else {

            throw new InternalError

                (MessageOutput.format("Invalid connect type"));

        }

        vm.setDebugTraceMode(traceFlags);

        if (vm.canBeModified()){

            setEventRequests(vm);

            resolveEventRequests();

        }

        /*

         * Now that the vm connection is open, fetch the debugee

         * classpath and set up a default sourcepath.

         * (Unless user supplied a sourcepath on the command line)

         * (Bug ID 4186582)

         */

        if (Env.getSourcePath().length() == 0) {

            if (vm instanceof PathSearchingVirtualMachine) {

                PathSearchingVirtualMachine psvm =

                    (PathSearchingVirtualMachine) vm;

                Env.setSourcePath(psvm.classPath());

            } else {

                Env.setSourcePath(".");

            }

        }

        return vm;

    }

    boolean setConnectorArg(String name, String value) {

        /*

         * Too late if the connection already made

         */

        if (vm != null) {

            return false;

        }

        Connector.Argument argument = connectorArgs.get(name);

        if (argument == null) {

            return false;

        }

        argument.setValue(value);

        return true;

    }

    String connectorArg(String name) {

        Connector.Argument argument = connectorArgs.get(name);

        if (argument == null) {

            return "";

        }

        return argument.value();

    }

    public synchronized VirtualMachine vm() {

        if (vm == null) {

            throw new VMNotConnectedException();

        } else {

            return vm;

        }

    }

    boolean isOpen() {

        return (vm != null);

    }

    boolean isLaunch() {

        return (connector instanceof LaunchingConnector);

    }

    public void disposeVM() {

        try {

            if (vm != null) {

                vm.dispose();

                vm = null;

            }

        } finally {

            if (process != null) {

                process.destroy();

                process = null;

            }

            waitOutputComplete();

        }

    }

    private void setEventRequests(VirtualMachine vm) {

        EventRequestManager erm = vm.eventRequestManager();

        // Normally, we want all uncaught exceptions.  We request them

        // via the same mechanism as Commands.commandCatchException()

        // so the user can ignore them later if they are not

        // interested.

        // FIXME: this works but generates spurious messages on stdout

        //        during startup:

        //          Set uncaught java.lang.Throwable

        //          Set deferred uncaught java.lang.Throwable

        Commands evaluator = new Commands();

        evaluator.commandCatchException

            (new StringTokenizer("uncaught java.lang.Throwable"));

        ThreadStartRequest tsr = erm.createThreadStartRequest();

        tsr.enable();

        ThreadDeathRequest tdr = erm.createThreadDeathRequest();

        tdr.enable();

    }

    private void resolveEventRequests() {

        Env.specList.resolveAll();

    }

    private void dumpStream(InputStream stream) throws IOException {

        BufferedReader in =

            new BufferedReader(new InputStreamReader(stream));

        int i;

        try {

            while ((i = in.read()) != -1) {

                   MessageOutput.printDirect((char)i);// Special case: use

                                                      //   printDirect()

            }

        } catch (IOException ex) {

            String s = ex.getMessage();

            if (!s.startsWith("Bad file number")) {

                  throw ex;

            }

            // else we got a Bad file number IOException which just means

            // that the debuggee has gone away.  We'll just treat it the

            // same as if we got an EOF.

        }

    }

    /**

     *  Create a Thread that will retrieve and display any output.

     *  Needs to be high priority, else debugger may exit before

     *  it can be displayed.

     */

    private void displayRemoteOutput(final InputStream stream) {

        Thread thr = new Thread("output reader") {

            public void run() {

                try {

                    dumpStream(stream);

                } catch (IOException ex) {

                    MessageOutput.fatalError("Failed reading output");

                } finally {

                    notifyOutputComplete();

                }

            }

        };

        thr.setPriority(Thread.MAX_PRIORITY-1);

        thr.start();

    }

    private void dumpFailedLaunchInfo(Process process) {

        try {

            dumpStream(process.getErrorStream());

            dumpStream(process.getInputStream());

        } catch (IOException e) {

            MessageOutput.println("Unable to display process output:",

                                  e.getMessage());

        }

    }

    /* launch child target vm */

    private VirtualMachine launchTarget() {

        LaunchingConnector launcher = (LaunchingConnector)connector;

        try {

            VirtualMachine vm = launcher.launch(connectorArgs);

            process = vm.process();

            displayRemoteOutput(process.getErrorStream());

            displayRemoteOutput(process.getInputStream());

            return vm;

        } catch (IOException ioe) {

            ioe.printStackTrace();

            MessageOutput.fatalError("Unable to launch target VM.");

        } catch (IllegalConnectorArgumentsException icae) {

            icae.printStackTrace();

            MessageOutput.fatalError("Internal debugger error.");

        } catch (VMStartException vmse) {

            MessageOutput.println("vmstartexception", vmse.getMessage());

            MessageOutput.println();

            dumpFailedLaunchInfo(vmse.process());

            MessageOutput.fatalError("Target VM failed to initialize.");

        }

        return null; // Shuts up the compiler

    }

    /* attach to running target vm */

    private VirtualMachine attachTarget() {

        AttachingConnector attacher = (AttachingConnector)connector;

        try {

            return attacher.attach(connectorArgs);

        } catch (IOException ioe) {

            ioe.printStackTrace();

            MessageOutput.fatalError("Unable to attach to target VM.");

        } catch (IllegalConnectorArgumentsException icae) {

            icae.printStackTrace();

            MessageOutput.fatalError("Internal debugger error.");

        }

        return null; // Shuts up the compiler

    }

    /* listen for connection from target vm */

    private VirtualMachine listenTarget() {

        ListeningConnector listener = (ListeningConnector)connector;

        try {

            String retAddress = listener.startListening(connectorArgs);

            MessageOutput.println("Listening at address:", retAddress);

            vm = listener.accept(connectorArgs);

            listener.stopListening(connectorArgs);

            return vm;

        } catch (IOException ioe) {

            ioe.printStackTrace();

            MessageOutput.fatalError("Unable to attach to target VM.");

        } catch (IllegalConnectorArgumentsException icae) {

            icae.printStackTrace();

            MessageOutput.fatalError("Internal debugger error.");

        }

        return null; // Shuts up the compiler

    }

}