/*
Copyright 2007 Creare Inc.

Licensed under the Apache License, Version 2.0 (the "License"); 
you may not use this file except in compliance with the License. 
You may obtain a copy of the License at 

http://www.apache.org/licenses/LICENSE-2.0 

Unless required by applicable law or agreed to in writing, software 
distributed under the License is distributed on an "AS IS" BASIS, 
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
See the License for the specific language governing permissions and 
limitations under the License.
*/

// VChansPlugIn - registers local channels, but fulfills requests for data
//                by querying the remote channels
// EMF
// February 2002
// Copyright 2002, 2004 Creare Incorporated
// Modified: INB 04/07/2004 - replaced the Request method with one that doesn't
// take the byFrame flag because that is no longer supported.

import com.rbnb.sapi.ChannelMap;
import com.rbnb.sapi.PlugIn;
import com.rbnb.sapi.PlugInChannelMap;
import com.rbnb.sapi.Sink;

import java.util.Enumeration;
import java.util.Hashtable;

public class VChansPlugIn {
  private String address=new String("localhost:3333"); //server to connect to
  private String sinkName=new String("VCsink"); //sink connection name
  private String pluginName=new String("VChans"); //plugin connection name
  private Hashtable toLocal=new Hashtable(); //for mapping virtual/real channels
  private Hashtable toRemote=new Hashtable();
  private PlugIn plugin=null; //plugin connection
  private Sink sink=null; //sink connection

  public VChansPlugIn(String[] args) {
    //parse args (expecting optional -a address, followed by remote/local
    //            channel name pairs)
    for (int i=0;i<args.length;i++) {
      if (args[i].startsWith("-a")) {
        if (args[i].length()==2) address=args[++i];
        else address=args[i].substring(2);
      } else {
        String remote=args[i];
        String local=args[++i];
        System.err.println("mapping "+remote+" to "+local);
        // fill up Hashtables, so can easily map virtual to/from real channels
        toLocal.put(remote,local);
        toRemote.put(local,remote);
      }
    }
  }

  public static void main(String[] args) {
    (new VChansPlugIn(args)).exec();
  }

  public void exec() {
    try {
      //make connections
      sink=new Sink();
      sink.OpenRBNBConnection(address,sinkName);
      plugin=new PlugIn();
      plugin.OpenRBNBConnection(address,pluginName);

      //register virtual channels
      ChannelMap cm=new ChannelMap();
      for (Enumeration e=toLocal.elements();e.hasMoreElements();) {
        cm.Add((String)e.nextElement());
      }
      plugin.Register(cm);

      //loop handling requests - note multithreaded would be better.
      //                       - does not support monitor/subscribe yet
      while (true) {
        PlugInChannelMap picm=plugin.Fetch(-1); //block until request arrives

        //map virtual to real channels
        cm=new ChannelMap();
        for (int i=0;i<picm.NumberOfChannels();i++) {
          cm.Add((String)toRemote.get(picm.GetName(i)));
        }

        //request data from real channels
	/* INB - this method is no longer supported.  04/07/2004
        sink.Request(cm,
                     picm.GetRequestStart(),
                     picm.GetRequestDuration(),
                     picm.GetRequestReference(),
                     picm.IsRequestFrames());
	*/
        sink.Request(cm,
                     picm.GetRequestStart(),
                     picm.GetRequestDuration(),
                     picm.GetRequestReference());
        cm=sink.Fetch(-1,cm);

        //copy data,times,types from real to virtual channels
        for (int i=0;i<cm.NumberOfChannels();i++) {
          int idx=picm.GetIndex((String)toLocal.get(cm.GetName(i)));
          if (idx>=0) {
            picm.PutTimeRef(cm,i);
            //EMF 1/24/03: switched to new PutDataRef call to avoid
            //             byte order ambiguity
            //picm.PutData(idx,cm.GetData(i),cm.GetType(i));
            picm.PutDataRef(idx,cm,i);
            picm.PutMime(idx,cm.GetMime(i));
          } else {
            System.err.println("Unable to match "+cm.GetName(i));
          }
        }
        //send response
        plugin.Flush(picm);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }//end exec method

}//end VChansPlugIn class