package cz.cuni.amis.pogamut.sposh.engine;
   
   import cz.cuni.amis.pogamut.sposh.engine.timer.SystemClockTimer;
   import cz.cuni.amis.pogamut.sposh.engine.timer.ITimer;
   import cz.cuni.amis.pogamut.sposh.elements.PoshPlan;
   import cz.cuni.amis.pogamut.sposh.executor.IWorkExecutor;
   import java.util.Set;
   import java.util.logging.Logger;
   
  /**
   * This class is responsible for executing the valid posh plan.
   * 
   * @author Honza
   */
  public class PoshEngine {
  
      public enum EvaluationResult {
          GOAL_SATISFIED,
          ELEMENT_FIRED,
          NO_ELEMENT_FIRED
      }
      
      public static class EvaluationResultInfo {
      	
      	public EvaluationResult result;
      	public FireResult.Type type;
      	
      	public EvaluationResultInfo(EvaluationResult result, FireResult.Type type) {
      		this.result = result;
      		this.type = type;
      	}
      	
      }
  
      protected PoshPlan plan;
      protected ITimer timer;
      protected Logger log;
      private DCExecutor dcExecutor;
  
      public PoshEngine(PoshPlan plan) {
          this(plan, new SystemClockTimer());
      }
  
      public PoshEngine(PoshPlan plan, ITimer timer) {
          this(plan, timer, null);
      }
  
      public PoshEngine(PoshPlan plan, ITimer timer, Logger log) {
          this.plan = plan;
          this.timer = timer;
          this.log = log;
          reset();
      }
  
      /**
       * Reset the posh engine, all stacks and variables will be reseted.
       * Use this to return engine to former state, it had when first initialized.
       */
      public final synchronized void reset() {
          dcExecutor = new DCExecutor(plan, new VariableContext(), timer, log);
      }
  
      public synchronized EvaluationResultInfo evaluatePlan(IWorkExecutor workExecuter) {
          EvaluationResultInfo ret = dcExecutor.fire(workExecuter);
          // DO NOT REMOVE. For details see javadoc of the method.
          evaluatePlanExit();
          return ret;
      }
  
      /**
       * <em>DO NOT REMOVE!!!</em> This method is here as a workaround of slow
       * Netbeans breakpoint API. The API is quite fast when adding a breakpoint
       * of {@link MethodBreakpoint#TYPE_METHOD_ENTRY} type, but <em>very
       * slow</em> (about 1.2 seconds penalty) when using the
       * {@link MethodBreakpoint#TYPE_METHOD_EXIT}. As a workaround, I am adding
       * an {@link MethodBreakpoint#TYPE_METHOD_ENTRY entry type} breakpoint to
       * this method that is used directly before returning from
       * {@link PoshEngine#evaluatePlan(cz.cuni.amis.pogamut.sposh.executor.IWorkExecutor)
       * }.
       */
      private void evaluatePlanExit() {
          // intentionally left empty
      }
      
      ElementStackTrace getStackForDE(String name) {
          return dcExecutor.getStackForDE(name);
      }
  
      
      ElementStackTrace getStackForDE(int index) {
          return dcExecutor.getStackForDE(index);
      }
      
      int getDECount() {
      	return dcExecutor.getDECount();
      }
      
      String getDEName(int index) {
      	return dcExecutor.getDEName(index);
     }
     
     public Logger getLog() {
     	return log;
     }
 
     /**
      * Get plan of this engine (serialize the parsed plane and return it). DO 
      * NOT MODIFY ANYTHING IN RETURNED PLAN!
      * @return
      */
     public final PoshPlan getPlan() {
         return plan;
     }
 
     /**
      * Convert posh tree into posh plan (textual representation) and return it.
      * @return Textual representation of the posh tree.
      */
     public final String getPoshPlan() {
         return plan.toString();
     }
     
     /**
      * Return serialized state of the engine. 
      * @return
      */
     public String getState() {
         StringBuilder sb = new StringBuilder();
         for (DEExecutor de : dcExecutor.deExecutors) {
             sb.append("/Root:");
             sb.append(plan.getDriveCollection().getName());
             sb.append("/Drive:");
             sb.append(de.getName());
             TriggerResult triggerResult = de.getTriggerResult();
             if (triggerResult != null) {
                 for (SenseResult senseResult : triggerResult) {
                     sb.append('[');
                     sb.append(senseResult.name);
                     sb.append(':');
                     sb.append(senseResult.wasSuccessful() ? '1' : '0');
                     sb.append(']');
                 }
             }
             sb.append(de.getStackTrace().toString());
             sb.append('\n');
         }
         return sb.toString();
     }
 }