import tokenizer
import token
import expression
import json

variables = {}
def print_vars(vars):
	i = 0
	for key in vars.keys():
		var = vars[key]
		if i != 0:
			print(", %s" %(var.name), end = "")
		else:
			print("%s " %(var.name), end = "")
		i += 1
	print()

def modify_variable(var, vars):
	print("%s is now selected." %(var.name))
	print("The following properties are avaliable: Variable Type, Starting Point and Ending Point.")
	print('Commands are "type", "start" and "end", respectly.')
	
	while True:
		response = input("Select a property to modify for %s or q to exit property modifying: " %(var.name))
		
		if response == "type":
			response = input("Enter the type of variable this is (currently %s): " %(expression.Variable.get_variable_type(var.type)))
			vars[var.name].type = response
			print("Updated to %s." %(response))
			
		elif response == "start":
			response = input("Enter the variable's starting point (currently %f): " %(var.starting_point))
			
			try:
				vars[var.name].starting_point = float(response)
				print("Updated to %f." %(float(response)))
			except ValueError:
				print("The starting point must be a number.")
			
		elif response == "end":
			response = input("Enter the variable's ending point (currently %f): " %(var.ending_point))
			
			try:
				vars[var.name].ending_point = float(response)
				print("Updated to %f." %(float(response)))
			except ValueError:
				print("The ending point must be a number.")
			
			pass
			
		elif response == "q":
			return
			
		else:
			print('Invalid property "%s".' %(response))
			print('Commands are "type", "start" and "end".')
			
def transform(object):

    if isinstance(object, expression.Expression) or isinstance(object, expression.Variable):

        return object.__dict__

    else:

        raise TypeError("Only Books and Index will be JSON serialized!")

exp = input("Enter the expression the student will use: ")
tokens = tokenizer.get_tokens_from_expression_string(exp)

for t in tokens:
	if t.type == token.TokenType.variable:
		variables[t.value] = expression.Variable(t.value, expression.Variable.get_variable_type(t.value))

selected_variable = None

while True:
	print("Variables in expression:")
	print_vars(variables)
	response = input("Enter a variable name to modify its properties or continue (default): ")
	
	if response == "continue" or response == "":
		break
		
	if response in variables:
		selected_variable = variables[response]
	
	if selected_variable != None:
		modify_variable(selected_variable, variables)
		
	else:
		print("Invalid selection %s." %(response))
		continue
		
with open("data.json", "w", encoding="utf-8") as f:
	json.dump(expression.Expression(exp, variables), f, default=transform, indent = 4)