package visitor;
   
   import calculator.Expression;
   import calculator.operations.Operation;
   import calculator.atoms.Complex;
   import calculator.atoms.IntegerAtom;
   import calculator.atoms.Rationnal;
   import calculator.atoms.Real;
   import calculator.functions.*;
  
  /**
   * Counter is a visitor that counts the numbers, operations,
   * and depth in an arithmetic expression.
   */
  public class Counter extends Visitor {
  
  	private int nbOps = 0;
  	private int nbNbs = 0;
  	private int maxDepth = 0;
  	private int currentDepth = 0;
  
  	/**
  	 * Default constructor.
  	 */
  	public Counter() {
  	}
  
  	@Override
  	public void visit(Real r) {
  		nbNbs += 1;
  		maxDepth = Math.max(maxDepth, currentDepth);
  	}
  
  	@Override
  	public void visit(IntegerAtom i) {
  		nbNbs += 1;
  		maxDepth = Math.max(maxDepth, currentDepth);
  	}
  
  	@Override
  	public void visit(Complex c) {
  		nbNbs += 1;
  		maxDepth = Math.max(maxDepth, currentDepth);
  	}
  
  	@Override
  	public void visit(Rationnal q) {
  		nbNbs += 1;
  		maxDepth = Math.max(maxDepth, currentDepth);
  	}
  
  	/**
  	 * Visit an operation: increments the operation count, then recursively
  	 * visits all child expressions to accumulate counts.
  	 *
  	 * @param o The operation being visited
  	 */
  	@Override
  	public void visit(Operation o) {
  		nbOps++;
  		currentDepth++;
  		for (Expression a : o.getArgs()) {
  			a.accept(this);
  		}
  		currentDepth--;
  	}
  
  	@Override
  	public void visit(UnaryFunction o) {
  		nbOps++;
  		currentDepth++;
  		o.getArg().accept(this);
  		currentDepth--;
  	}
  
  	@Override
  	public void visit(BinaryFunction f) {
  		nbOps++;
  		currentDepth++;
  		f.getFirstArg().accept(this);
  		f.getSecondArg().accept(this);
  		currentDepth--;
  	}
  
  	/**
  	 * Gets the number of operations.
  	 * 
  	 * @return The number of operations in the expression
  	 */
  	public int getNbOps() {
  		return nbOps;
  	}
  
  	/**
  	 * Gets the number of numbers.
  	 * 
  	 * @return The number of numbers in the expression
  	 */
  	public int getNbNbs() {
 		return nbNbs;
 	}
 
 	/**
 	 * Gets the depth.
 	 * 
 	 * @return The depth (0 for a number, 1 for a simple operation, etc.)
 	 */
 	public int getDepth() {
 		return maxDepth;
 	}
 
 }