/* Copyright (C) 2007 Michael Goffioul
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; If not, see <http://www.gnu.org/licenses/>.
*/

package org.octave;

import java.util.*;

public class Octave
{
  private static Object notifyObject = null;
  private static Object[] args = null;
  private static LinkedList invokeList = new LinkedList();
  private static LinkedList waitList = new LinkedList();

  public native static boolean call (String name, Object[] argin, Object[] argout);
  public native static void doInvoke(int ID, Object[] args);
  public native static void doEvalString(String cmd);
  public native static boolean needThreadedInvokation();

  public static void checkPendingAction()
    {
      if (notifyObject != null)
        {
          synchronized(notifyObject)
            {
              if (notifyObject instanceof OctaveReference)
                doInvoke(((OctaveReference)notifyObject).getID(), args);
              else if (notifyObject instanceof String)
                doEvalString((String)notifyObject);
              notifyObject.notifyAll();
            }
          notifyObject = null;
          args = null;
        }

      Object obj;
      Object[] objArgs;

      while (true)
        {
          obj = null;
          objArgs = null;

          synchronized (invokeList)
            {
              if (invokeList.size() > 0)
                {
                  obj = invokeList.remove();
                  if (obj instanceof OctaveReference)
                    objArgs = (Object[])invokeList.remove();
                }
            }

          if (obj != null)
            {
              if (obj instanceof Runnable)
                ((Runnable)obj).run();
              else if (obj instanceof OctaveReference)
                doInvoke(((OctaveReference)obj).getID(), objArgs);
              else if (obj instanceof String)
                doEvalString((String)obj);
            }
          else
            break;
        }
      /*
      synchronized(invokeList)
        {
          while (invokeList.size() > 0)
            {
              Object obj = invokeList.remove();
	      if (obj instanceof Runnable)
                ((Runnable)obj).run();
              if (obj instanceof OctaveReference)
                {
                  Object[] objArgs = (Object[])invokeList.remove();
                  doInvoke(((OctaveReference)obj).getID(), objArgs);
                }
              else if (obj instanceof String)
                doEvalString((String)obj);
            }
        }
        */
    }

  private static void checkWaitState()
    {
      if (waitList.size() > 0)
        {
          Object wObj = waitList.getFirst();
          synchronized (wObj)
            {
              wObj.notifyAll();
            }
        }
    }

  public static void invokeAndWait(OctaveReference ref, Object[] invokeArgs)
    {
      if (needThreadedInvokation())
        {
          synchronized(ref)
            {
              notifyObject = ref;
              args = invokeArgs;
              try { checkWaitState(); ref.wait(); }
              catch (InterruptedException e) {}
            }
        }
      else
        doInvoke(ref.getID(), invokeArgs);
    }

  public static void evalAndWait(String cmd)
    {
      if (needThreadedInvokation())
        {
          synchronized(cmd)
            {
              notifyObject = cmd;
              args = null;
              try { checkWaitState(); cmd.wait(); }
              catch (InterruptedException e) {}
            }
        }
      else
        doEvalString(cmd);
    }

  public static void invokeLater(Runnable r)
    {
      if (needThreadedInvokation())
        synchronized(invokeList)
          {
            invokeList.add(r);
            checkWaitState();
          }
      else
        r.run();
    }

  public static void invokeLater(OctaveReference ref, Object[] invokeArgs)
    {
      if (needThreadedInvokation())
        synchronized(invokeList)
          {
            invokeList.add(ref);
            invokeList.add(invokeArgs);
            checkWaitState();
          }
      else
        doInvoke(ref.getID(), invokeArgs);
    }

  public static void evalLater(String cmd)
    {
      if (needThreadedInvokation())
        synchronized(invokeList)
          {
            invokeList.add(cmd);
            checkWaitState();
          }
      else
        doEvalString(cmd);
    }

  public static void waitFor(Object wObj)
    {
      waitList.add(0, wObj);
      synchronized (wObj)
        {
          while (waitList.size() > 0 && waitList.getFirst() == wObj)
            {
              try { wObj.wait(); }
              catch (InterruptedException e) {}
              checkPendingAction();
            }
        }
    }

  public static void endWaitFor(Object obj)
    {
      boolean isCurrentWaitObject = (waitList.size() > 0 && waitList.getFirst() == obj);

      waitList.remove(obj);
	  if (needThreadedInvokation() && isCurrentWaitObject)
        synchronized (obj)
          {
            obj.notifyAll();
          }
    }

  public static Object do_test (String name, Object arg0) throws Exception
    {
      Object[] argin = new Object[] { arg0 };
	  Object[] argout = new Object[1];
      if (call (name, argin, argout))
        return argout[0];
      throw new Exception ("octave call failed");
    }
}