/*
   * The contents of this file are subject to the BT "ZEUS" Open Source 
   * Licence (L77741), Version 1.0 (the "Licence"); you may not use this file 
   * except in compliance with the Licence. You may obtain a copy of the Licence
   * from $ZEUS_INSTALL/licence.html or alternatively from
   * http://www.labs.bt.com/projects/agents/zeus/licence.htm
   * 
   * Except as stated in Clause 7 of the Licence, software distributed under the
   * Licence is distributed WITHOUT WARRANTY OF ANY KIND, either express or 
  * implied. See the Licence for the specific language governing rights and 
  * limitations under the Licence.
  * 
  * The Original Code is within the package zeus.*.
  * The Initial Developer of the Original Code is British Telecommunications
  * public limited company, whose registered office is at 81 Newgate Street, 
  * London, EC1A 7AJ, England. Portions created by British Telecommunications 
  * public limited company are Copyright 1996-9. All Rights Reserved.
  * 
  * THIS NOTICE MUST BE INCLUDED ON ANY COPY OF THIS FILE
  */
  /*
   * @(#)b2.java 1.03b
   */
  
  
  package zeus.actors.graphs;
  
  import java.util.*;
  import zeus.util.*;
  import zeus.concepts.*;
  import zeus.actors.*;
  import zeus.actors.rtn.*;
  import zeus.actors.rtn.util.*;
  
  /*** 
      this is a node in the contract net protocol that is the default co-ordination 
      mechanism of zeus. 
      */
  public class b2 extends Node {
     protected static final double DELTA_TIME = 0.25;
    
     
     // ST 050500 1.03bB node description due to CVB
     private String node_desc = "do/find protocols";
     
     
     public final String getDesc()
        {return node_desc;}
     
     
     public final void setDesc(String node_desc) 
        {this.node_desc = node_desc;}
     // ST 050500 1.03bE
  
  
     public b2() {
        super("b2");
     }
  
     // memory useful for backtracking
  
     protected Graph[] local_graph = null;
     protected LocalDStruct[] local_dstruct = null;
     protected int reply_needed = 0;
  
     protected int exec() {
        Engine engine = context.Engine();
        MsgHandler handler = context.MsgHandler();
        ProtocolDb protocolDb = context.ProtocolDb();
  
        DStruct ds = (DStruct)input;
        output = input;
  
        Goal g = (Goal)ds.goal.elementAt(0);
        double ct = g.getConfirmTime().getTime();
        timeout = ct-DELTA_TIME;
  
        Core.DEBUG(3,getDescription() + " Pre-timeout = " + timeout);
        Core.DEBUG(3,getDescription() + " ds.gs.timeout = " + ds.gs.timeout);
        if ( !Misc.isZero(ds.gs.timeout) )
           timeout = Math.min(timeout,context.now() + ds.gs.timeout);
  
        Core.DEBUG(3,getDescription() + " Post-timeout = " + timeout);
  
        Time t = new Time(timeout);
        for(int i = 0; i < ds.goal.size(); i++ ) {
           g = (Goal) ds.goal.elementAt(i);
           g.setReplyTime(t);
        }
  
        msg_wait_key = context.newId("ProtocolInitiator");
  
        // Get applicable protocol & strategy for this fact/agent combination
        Fact fact = g.getFact();
        Vector info = protocolDb.getProtocols(fact,Misc.stringArray(ds.agents),
           ProtocolInfo.INITIATOR);
  
        if ( info.isEmpty() ) return FAIL;
  
       // Identify all independent agents in info
       // next, select the first ProtocolDbResult for each identified agent
       // next create local_graph for each agent then launch graphs
 
       HSet agents = new HSet();
       ProtocolDbResult result;
       for(int i = 0; i < info.size(); i++ ) {
          result = (ProtocolDbResult)info.elementAt(i);
          agents.add(result.agent);
       }
 
       String r_price = Double.toString(g.getCost());
       ProtocolDbResult[] protocols = new ProtocolDbResult[agents.size()];
       Enumeration enum = agents.elements();
       String agent;
       for(int j = 0; enum.hasMoreElements(); j++ ) {
          agent = (String)enum.nextElement();
          for(int i = 0; i < info.size(); i++ ) {
             result = (ProtocolDbResult)info.elementAt(i);
             if ( result.agent.equals(agent) ) {
                protocols[j] = result;
                protocols[j].parameters.put("reservation.price",r_price);
                break;
             }
          }
       }
 
       MessagePattern pattern = null;
       MessageAction action = null;
 
       local_graph = new Graph[protocols.length];
       local_dstruct = new LocalDStruct[protocols.length];
 
       for(int i = 0; i < local_graph.length; i++ ) {
          local_graph[i] = createGraph(protocols[i].protocol);
          if ( local_graph[i] != null ) {
             local_dstruct[i] = new LocalDStruct(protocols[i].agent,ds);
             local_dstruct[i].any = protocols[i];
             local_dstruct[i].key = context.newId("local_dstruct");
 
             pattern = new MessagePatternImpl();
             pattern.setConstraint("in-reply-to",local_dstruct[i].key);
             action = new MessageActionImpl(engine,"continue_dialogue");
             handler.addRule(new MessageRuleImpl(local_dstruct[i].key,pattern,action));
 
             local_graph[i].run(engine,this,local_dstruct[i],msg_wait_key);
             reply_needed++;
          }
          else
             local_dstruct[i] = null;
       }
       return (reply_needed > 0) ? WAIT : FAIL;
    }
 
    protected int continue_exec() {
       DStruct ds = (DStruct)input;
       output = input;
 
       int transaction_completed = 0;
 
       for(int i = 0; i < local_graph.length; i++ ) {
          if ( local_graph[i] != null ) {
             switch( local_graph[i].getState() ) {
             case Graph.DONE:
                  if ( !ds.results.contains(local_dstruct[i].result) )
                     ds.results.addElement(local_dstruct[i].result);
                  transaction_completed++;
   	         break;
             case Graph.FAILED:
                  transaction_completed++;
   	         break;
             }
          }
       }
       
       Core.DEBUG(3,getDescription() + "No Needed: " + reply_needed +
          "  completed: " + transaction_completed);
 
       if ( reply_needed - transaction_completed == 0 ) return OK;
       if ( timeout > context.now() )
          return WAIT;
       else
          return OK;
    }
 
    protected void reset() {
       // reset any state changed by exec()
       DStruct ds = (DStruct)input;
       ds.results.removeAllElements();
    }
 }