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.DriveCollection;
   import cz.cuni.amis.pogamut.sposh.elements.DriveElement;
   import cz.cuni.amis.pogamut.sposh.elements.PoshPlan;
   import cz.cuni.amis.pogamut.sposh.engine.PoshEngine.EvaluationResult;
   import cz.cuni.amis.pogamut.sposh.executor.IWorkExecutor;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.logging.Logger;
  
  /**
   * This class is responsible for valuating the DriveCollection element.
   *
   * @author HonzaH
   */
  final class DCExecutor extends AbstractExecutor {
  
      private SenseListExecutor<DriveCollection> goalExecutor;
      List<DEExecutor> deExecutors = new ArrayList<DEExecutor>();
      private DEExecutor lastTriggeredDrive = null;
      private ITimer timer;
      private TriggerResult triggerResult;
      
  
      /**
       * Create DCExecutor with SystemClockTimer.
       *
       * @param dc
       * @param ctx
       */
      protected DCExecutor(PoshPlan plan, VariableContext ctx) {
          this(plan, ctx, new SystemClockTimer(), null);
      }
  
      protected DCExecutor(PoshPlan plan, VariableContext ctx, ITimer timer, Logger log) {
          super(ctx, log);
  
          DriveCollection dc = plan.getDriveCollection();
          this.timer = timer;
          this.goalExecutor = new SenseListExecutor<DriveCollection>(dc.getGoal(), ctx, log);
  
          for (DriveElement de : dc.getDrives()) {
              deExecutors.add(new DEExecutor(plan, de, ctx, log));
          }
      }
  
      public synchronized PoshEngine.EvaluationResultInfo fire(IWorkExecutor workExecuter) {
          FireResult.Type resultType = null;
          triggerResult = goalExecutor.fire(workExecuter, false);
          if (triggerResult.wasSuccess()) {
              return new PoshEngine.EvaluationResultInfo(EvaluationResult.GOAL_SATISFIED, FireResult.Type.FULFILLED);
          }
          // TODO: Rework whole engine, currently I need to clear trigger re4sults of DEExecutor every loop
          // because they would linger, although never fired in the loop
          for (DEExecutor deExecutor : deExecutors) {
              deExecutor.clearTriggerResult();
          }
  
          for (DEExecutor deExecutor : deExecutors) {
              if (deExecutor.isReady(timer.getTime(), workExecuter)) {
              	if (lastTriggeredDrive != null && lastTriggeredDrive != deExecutor) {
              		// DRIVE SWITCH
              		// Some drive that has more priority than "lastTriggeredDrive" has to fire
              		// => clean up the stack of deExecutor
              		lastTriggeredDrive.driveInterrupted();            		
              	}            	
              	lastTriggeredDrive = deExecutor;
                  resultType = deExecutor.fire(workExecuter, timer);
                  return new PoshEngine.EvaluationResultInfo(EvaluationResult.ELEMENT_FIRED, resultType);
              }
          }
          return new PoshEngine.EvaluationResultInfo(EvaluationResult.NO_ELEMENT_FIRED, FireResult.Type.FAILED);
      }
      
      int getDECount() {
      	return deExecutors.size();
      }
      
      String getDEName(int index) {
      	return deExecutors.get(index).getName();
      }
  
      ElementStackTrace getStackForDE(int index) {
          return deExecutors.get(index).getStackTrace();
      }
  
      /**
       * Get ElementStackTrace for the drive element with name "name." If there
       * are two drive elements with same name, throw IllegalStateException.
       *
       * @param name name of drive element we are looking for
       * @return stacktrace for element if element with such name exists, else
       * null.
       */
      ElementStackTrace getStackForDE(String name) {
          DEExecutor result = null;
         for (DEExecutor de : deExecutors) {
             boolean equal = de.getName() == null ? name == null : de.getName().equals(name);
             if (equal) {
                 if (result == null) {
                     result = de;
                 } else {
                     throw new IllegalStateException("Two drive elements with name \"" + name + "\".");
                 }
             }
         }
         if (result != null) {
             return result.getStackTrace();
         }
 
         return null;
     }
 
     // TODO: Change DC executor into an ElementExecutor
     public TriggerResult getTriggerResult() {
         return triggerResult;
     }
 }