/*
   * 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
  */
  
  /*
   * @(#)b1.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.*;
  
  public class b1 extends Node {
  /***
     Purpose: for a predefined fraction of the period (confirm_time - now)
     subscribe to the facilitator to stream list of all agents with required
     ability: collect set of agents received
  */
  
  // ST 050500 1.03bB node description due to CVB
     private String node_desc = "do/find sellers; do\find service";
     
     
     public final String getDesc()
        {return node_desc;}
     
     
     public final void setDesc(String node_desc) 
        {this.node_desc = node_desc;}
     // ST 050500 1.03bE
     
  
     public b1() {
        super("b1");
     }
  
     // local memory
     static final double FRACTION = 0.50;
     boolean proceed_immediately;
  
     protected int exec() {
       
        OrganisationDb db = context.OrganisationDb();
        
        OntologyDb ontology = context.OntologyDb();
        Engine engine = context.Engine();
        MailBox mbox = context.MailBox();
  
        DStruct ds = (DStruct)input;
        // assume ds.goal has one element only
         debug ("1"); 
        Goal goal = (Goal)ds.goal.elementAt(0);
        String type = goal.getFactType();
        double t = goal.getConfirmTime().getTime();
        double now = context.now();
        debug ("2"); 
        if ( now >= t ) return FAIL;
  
        // if no facilitators are listed, then directly query organisationDb
        // and return
  
        if ( context.facilitators().isEmpty() ) {
           if ( !ds.ignore.contains(context.whoami()) )
              ds.ignore.addElement(context.whoami());
           ds.agents = db.anyAgent(goal,ds.ignore);
           ds.ignore = Misc.union(ds.agents,ds.ignore);
  
           Core.DEBUG(2,"b1 ds.agents = " + ds.agents);
  
           output = input;
           return ds.agents.isEmpty() ? FAIL : OK;
        }
        debug ("3"); 
        // otherwise
        // subscribe to facilitators send list of agents with required ability
        timeout = now + FRACTION*(t-now);
        AbilitySpec a = new AbilitySpec(ontology.getFact(Fact.VARIABLE,type),0,0);
 
       Performative msg;
       msg_wait_key = context.newId();
       String[] pattern = { "type", "inform", "in-reply-to", msg_wait_key };
 
       proceed_immediately = ds.gs.any != null && ((Boolean)ds.gs.any).booleanValue();
       debug("4"); 
       String msg_type;
        debug("4a"); 
       if ( proceed_immediately ) {
            debug("4b"); 
           context.MsgHandler().addRule(new MessageRuleImpl(msg_wait_key, pattern,
             MessageActionImpl.EXECUTE_ONCE,engine,"agentWithAbilityFound")
           );
           msg_type = "query-ref";
            debug("4c"); 
       }
       else {
            debug("4d"); 
          context.MsgHandler().addRule(new MessageRuleImpl(msg_wait_key, pattern,
             engine,"agentWithAbilityFound")
          );
           msg_type = "subscribe";
            debug("4e"); 
       }
       debug ("5"); 
       for(int i = 0; i < context.facilitators().size(); i++ ) {
            debug ("5a"); 
          msg = new Performative(msg_type);
           debug ("5b"); 
          msg.setReceiver((String)context.facilitators().elementAt(i));
           debug ("5c"); 
          msg.setContent("has_ability " + a);
           debug ("5d"); 
          msg.setReplyWith(msg_wait_key);
           debug ("5e"); 
          mbox.sendMsg(msg);
           debug ("5f"); 
       }
       Thread.yield(); 
       return WAIT;
    }
 
    protected int continue_exec() {
       MailBox mbox = context.MailBox();
       OrganisationDb db = context.OrganisationDb();
       debug ("6"); 
       if ( proceed_immediately || context.now() > timeout ) {
 
          if ( !proceed_immediately ) {
             debug ("6a"); 
             context.MsgHandler().removeRule(msg_wait_key);
             debug("7"); 
             Performative msg;
             for(int i = 0; i < context.facilitators().size(); i++ ) {
                msg = new Performative("cancel");
                msg.setReceiver((String)context.facilitators().elementAt(i));
                msg.setContent("has_ability " + msg_wait_key);
                mbox.sendMsg(msg);
             }
          }
          debug ("8a"); 
          DStruct ds = (DStruct)input;
          // assume ds.goal has one element only
          Goal goal = (Goal)ds.goal.elementAt(0);
          ds.agents = db.anyAgent(goal,ds.ignore);
          ds.ignore = Misc.union(ds.agents,ds.ignore);
          debug ("8b"); 
          Core.DEBUG(2,"b1 ds.agents = " + ds.agents);
 
          output = input;
          if (ds.agents.isEmpty () ) { 
                 debug ("9"); 
                 Thread.yield(); 
                 return FAIL; 
          }
          else {
             debug ("10");
             return OK; 
          }
             
          //return ds.agents.isEmpty() ? FAIL : OK;
       }
       return WAIT;
    }
 
    protected void reset() {
    }
    
    private void debug (String str) { 
        // System.out.println("b1>> " + str); 
    }
 }