/*
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.
*/

// VSourcePlugIn - creates a local source, but fulfills requests by
//                 querying the remote source
// EMF
// February 2002
// Copyright 2002 Creare Incorporated

import com.rbnb.sapi.ChannelMap;
import com.rbnb.sapi.ChannelTree;
import com.rbnb.sapi.ChannelTree.Node;
import com.rbnb.sapi.PlugIn;
import com.rbnb.sapi.PlugInChannelMap;
import com.rbnb.sapi.Sink;
import com.rbnb.utility.ArgHandler; //for argument parsing
import com.rbnb.utility.RBNBProcess; //alternative to System.exit, so
                                       //don't bring down servlet engine

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;

public class VSourcePlugIn {
  private String address=new String("localhost:3333"); //server to connect to
  private String sinkName=new String("VSsink"); //sink connection name
  private String pluginName=new String("VSource"); //plugin connection name
  private PlugIn plugin=null; //plugin connection
  private Sink sink=null; //sink connection
  private String remoteSource=null; //name of remote source
  private int debug=0;

  public VSourcePlugIn(String[] args) {
    //parse args
    try {
      ArgHandler ah=new ArgHandler(args);
      if (ah.checkFlag('a')) {
        String addressL=ah.getOption('a');
        if (addressL!=null) address=addressL;
      }
      if (ah.checkFlag('s')) {
        String source=ah.getOption('s');
        if (source!=null) remoteSource=source;
        //channel name completion easier if always ends in /
        if (!remoteSource.endsWith("/")) remoteSource=remoteSource+"/";
      }
      if (ah.checkFlag('n')) {
        String name=ah.getOption('n');
        if (name!=null) pluginName=name;
      }
    } catch (Exception e) {
      System.err.println("VSourcePlugIn argument exception "+e.getMessage());
      e.printStackTrace();
      RBNBProcess.exit(0);
    }
    //source must be specified
    if (remoteSource==null) {
      System.err.println("VSourcePlugIn: source must be specified with -s flag");
      RBNBProcess.exit(0);
    }
  }

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

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

      //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 channels to remote source 
        ChannelMap cm=new ChannelMap();
        for (int i=0;i<picm.NumberOfChannels();i++) {
//System.err.println("VSource picm channel "+picm.GetName(i));
          cm.Add(remoteSource+picm.GetName(i));
        }
		String[] folder=picm.GetFolderList();
		for (int i=0;i<folder.length;i++) {
//System.err.println("VSource in folder "+folder[i]);
			cm.AddFolder(remoteSource+folder[i]);
		}

        //request data from remote source
        sink.Request(cm,
                     picm.GetRequestStart(),
                     picm.GetRequestDuration(),
                     picm.GetRequestReference());
        cm=sink.Fetch(-1,cm);

        //copy data,times,types to answer original request
		folder=cm.GetFolderList();
		for (int i=0;i<folder.length;i++) {
//System.err.println("VSource cm folder "+folder[i]);
			if (folder[i].startsWith(remoteSource)) {
				folder[i]=folder[i].substring(remoteSource.length());
				if (folder[i].length()>0) {
//System.err.println("VSource out folder "+folder[i]);
					int idx=picm.GetIndex(folder[i]);
					if (idx==-1) picm.AddFolder(folder[i]);
				}
			} else {
				//may get folder that is shorter than remote source if source or
				// routed server is gone, so don't complain about it...
				//System.err.println("VSourcePlugIn: unexpected remote folder "+folder[i]);
			}
		}
				
        for (int i=0;i<cm.NumberOfChannels();i++) {
          String chan=cm.GetName(i);
//System.err.println("VSource cm chan "+chan);
          if (chan.startsWith(remoteSource)) {

            chan=chan.substring(remoteSource.length());
            int idx=picm.GetIndex(chan);
            if (idx==-1) idx=picm.Add(chan);
    
            //EMF 1/24/03: switch to new PutDataRef call to avoid
            //             byte order ambiguity
			picm.PutTimeRef(cm,i);
			picm.PutDataRef(idx,cm,i);
          } else {
            System.err.println("VSourcePlugIn: unexpected remote channel "+cm.GetName(i));
          }
        }

        //send response
        plugin.Flush(picm);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }//end exec method

}//end VSourcePlugIn class