import re

class Expression:

    def __init__(self, val=None, gauche=None, droite=None):
        if Token.isNumber(val) and (gauche != None or droite != None):
            raise AttributeError("gauche et droite ne peuvent pas exister si val est un nombre")
        self.val = val
        self.gauche = gauche
        self.droite = droite

    def evalue(self):
        if self.val == Token.OPERAND_ADDITION:
            return self.gauche.evalue() + self.droite.evalue()
        elif self.val == Token.OPERAND_MULTIPLICATION:
            return self.gauche.evalue() * self.droite.evalue()
        else:
            return int(self.val)

    def __str__(self):
        if Token.isNumber(self.val):
            return str(self.val)
        return "(" + str(self.gauche.__str__()) + str(self.val) + str(self.droite.__str__()) + ")"


class Token:
    ADDITION = "+"
    MULTIPLICATION = "*"
    PARENTHESE_OUVERTE = "("
    PARENTHESE_FERME = ")"

    NUMBER = re.compile(r'\d+')

    @staticmethod
    def isNumber(n):
        return Token.NUMBER.match(str(n)) is not None

def tokenize(text):
    buffer = ""
    tokens = []
    for char in text:
        if Token.isNumber(char):
            buffer += char
            continue
        elif char == " ":
            continue

        if buffer != "":
            tokens.append(buffer)
            buffer = ""
        tokens.append(char)
    return tokens

def arbre(tokens): #-> Expression
    print(tokens)
    current = None
    waiting_before_exp = None
    waiting_for_after_exp = None

    ##Brackets loop
    i = 0
    while i != len(tokens):
        if tokens[i] == "(":
            j = i + 1
            innerBrackets = 1
            innerTokens = []
            while tokens[j] != ")" and innerBrackets != 0:
                if tokens[j] == "(":
                    innerBrackets += 1
                elif tokens[j] == ")":
                    innerBrackets -= 1
                innerTokens.append(tokens[j])
                j += 1
            exp = arbre(innerTokens)
            if waiting_for_after_exp != None:
                waiting_for_after_exp.droite == exp
            else:
                waiting_before_exp = exp
        elif tokens[i] == "*":
            exp = Expression("*")
            if Token.isNumber(tokens[i-1]):
                exp.gauche == tokens[i-1]
            if Token.isNumber(tokens[i+1]):
                exp.droite == tokens[i+1]
            if Token.isNumber(tokens[i-1]) and Token.isNumber(tokens[i+1]):
                return exp

            if tokens[i-1] == ")":
                exp.gauche == waiting_before_exp
                waiting_before_exp = None
            elif tokens[i+1] == "(":
                waiting_for_after_exp = exp
            else:
                raise Exception()
            
            
        i += 1

    ##Multiplication loop
    #i = 0
    #while i != len(tokens):
    #    if tokens[i] == "*":
    #        print("at")
    #        return Expression("*", tokens[i-1], tokens[i+1])
    #    i += 1
    ##Addition loop
    #i = 0
    #while i != len(tokens):
    #    if tokens[i] == "+":
    #        return Expression("+", tokens[i-1], tokens[i+1])
    #    i += 1

    return waiting_for_after_exp



if __name__ == "__main__":
    print(arbre(tokenize("4*(7*4)")))