class AbacusCore:

    def __init__(self):
        self._input_string = input
        self._vars = dict()
        self._funcs = dict()

        self._vars['alphabet'] = 28
        self._vars['alpha'] = 1
        self._vars['beta'] = 2

        self._funcs['r2'] = lambda x: round(x, 2)
        self._funcs['r0'] = lambda x: int(x)
        self._funcs['summe'] = self.summe


    def summe(self, l):
        s = 0
        for ss in l:
            s = s + ss
        return s


    def _calculate(self, input_str):
        try:
            return True, eval(input_str)
        except ZeroDivisionError:
            res = 'Division by Zero'
        except NameError as e:
            res = 'Variable '+ e.name + ' not exists'
        except SyntaxError as e:
            res = 'Syntax Error'
        return False, res

    def get_vars(self):
        return self._vars

    def add_var(self, name, value):
        self._vars[name] = value

    def parse_input(self, input_str):
        '''
        versuche input_str zu parsen in comment vars und andere teile
        :param input_str:
        :return:
        '''
        input_str, comment = self._get_input_wo_commentar(input_str)
        input_str = ''.join(input_str.split())  # entferne alle leerzeichen
        if input_str is not None:
            for chunk in self._is_new_variable(input_str):  # chunks für variablenzuweisung
                self._replace_vars(chunk)
        else:
            return ('comment', comment)


    def _replace_vars(self, input_str):
        '''
        try to find vars and replace them
        :param input_str:
        :return:
        '''
        first_position = None
        new_input_str = ''
        for i, c in enumerate(input_str):
            if c.isalpha():
                if first_position is None:
                    first_position = i
                # print('alpha'+c)
            elif c == '=':
                if first_position is not None:  # variablenzuweisung
                    self._vars[input_str[first_position:i]] = None  # todo: wie machen?
                else:  # keine variable angegeben todo: womöglich eine tempvariable?
                    raise ValueError()
            elif c.isnumeric() or c in ['+', '-', '/', '*', '(', ')', '[', ']', ';']:
                if first_position is not None:
                    temp_var = input_str[first_position:i]
                    print('var', temp_var)
                    var = self._vars.get(temp_var)
                    if var is not None:
                        new_input_str +=str(var)
                    else:
                        raise ValueError()
                    first_position = None
                new_input_str += input_str[i]
        print(new_input_str)

    def _get_input_wo_commentar(self, input_str):
        '''
        Zerlege input in input und kommentar
        :param input_str:
        :return:
        '''
        input_str = input_str.strip()
        comment_index = input_str.find('#')
        if comment_index == 0:  # die ganze zeile ist ein kommentar
            return (None, input_str)
        elif comment_index == -1:
            return (input_str, None)
        else:
            comment = input_str[comment_index + 1:]
            input_str = input_str[:comment_index]
            return (input_str, comment)


    def _is_new_variable(self, input_str):
        chunks = input_str.split('=')
        chunks.reverse()
        return chunks