package cz.cuni.amis.pogamut.sposh.engine;
   
   import java.util.ArrayList;
   
   /**
    * One level in callstack.
    */
   class StackElement<T extends ElementExecutor> {
   
      public final String name;
      public final Class clazz;
      public final T executor;
  
      StackElement(Class clazz, String name, T executor) {
          this.clazz = clazz;
          this.name = name;
          this.executor = executor;
      }
  
      @Override
      public String toString() {
          return "StackElement[" + clazz.getSimpleName() + ":" + name + ":" + executor + "]";
      }
  
      T getExecutor() {
          return executor;
      }
  }
  
  /**
   * Callstack used for storing info what was call hiearchy of elements.
   *
   * @author Honza
   */
  final class ElementStackTrace extends ArrayList<StackElement> {
  
      public void push(StackElement element) {
      	add(element);
      }
      
      public StackElement pop() {
      	if (size() == 0) return null;
      	return remove(size()-1);
      }
      
      public StackElement peek() {
      	if (size() == 0) return null;
      	return get(size()-1);
      }
      
      public void removeAllElements() {
      	clear();
      }
      
      /**
       * Pops all elements until 'executor' is encountered. Pops 'executor' out of the stack as well.
       * 
       * If 'null' is passed as 'executor', removes whole stack.
       * 
       * @param executor
       */
      public void cutDownToIncluding(ElementExecutor executor) {
      	if (executor == null) {
      		removeAllElements();
      		return;
      	}
  		while (size() != 0 && peek().getExecutor() != executor) {
  			pop();
  		}
  		if (size() > 0) pop(); // pops 'executor' as well
  	}
      
      /**
       * Pops all elements until 'executor' is encountered. Leaves 'executor' on the stack.
       * 
       * If 'null' is passed as 'executor', removes whole stack.
       * 
       * @param executor
       */
      public void cutDownToExcluding(ElementExecutor executor) {
      	if (executor == null) {
      		removeAllElements();
      		return;
      	}
  		while (size() != 0 && peek().getExecutor() != executor) {
  			pop();
  		}
  		// leave executor on the stack
  	}
  }