import ptoken
import parser

debug = False

def calculate_results(node):
	
	if type(node) is parser.Num:
		return float(node.value)
	
	left = calculate_results(node.left)
	right = calculate_results(node.right)
	
	return operate(left, right, node.op)
	
def operate(n1, n2, tokenType):
	# Utility function to handle dealing with the various mathmatical operations that the engine can process.
	# Returns the result of any one of five mathmatical operations, else throws an error for unrecognized operations.
	n1 = float(n1)
	n2 = float(n2)
	
	if tokenType == ptoken.TokenType.add:
		if debug: print("Adding %f and %f to get %f." %(n1, n2, n1 + n2))	
		return n1 + n2
	elif tokenType == ptoken.TokenType.subtract:
		if debug: print("Subtracting %f and %f to get %f." %(n1, n2, n1 - n2))
		return n1 - n2
	elif tokenType == ptoken.TokenType.multiply:
		if debug: print("Multiplying %f and %f to get %f" %(n1, n2, n1 * n2))	
		return n1 * n2
	elif tokenType == ptoken.TokenType.divide:
		if debug: print("Dividing %f and %f to get %f" %(n1, n2, n1 / n2))	
		return n1 / n2
	elif tokenType == ptoken.TokenType.power:
		if debug: print("Raising %f to the power of %f to get %f" %(n1, n2, n1**n2))
		return n1 ** n2
	else:
		raise TypeError("Invalid operator value " + str(tokenType) + ".", tokenType)