from .types import SupportSign, SentenceConjunction, SentenceVariable, Negation


def is_formula_correct(formula):
    """ Run all test on formula """
    if not formula:
        return True

    else:
        formula = formula.replace(' ', '')
        return all([check_order(formula), check_parenthesis(formula)])


def check_parenthesis(formula: str) -> bool:
    """ Check if all brackets are opened and closed correctly """
    stack_of_expected_sings = []

    for sign in formula:
        if sign in SupportSign.symbols_open:
            inverse_of_sign = SupportSign.get_closed_symbol(sign)
            stack_of_expected_sings.append(inverse_of_sign)
        elif sign in SupportSign.symbols_close:
            if stack_of_expected_sings.pop() != sign:
                return False

    return not stack_of_expected_sings


def check_order(formula: str) -> bool:
    """ Check if all sings have correct preceding and next sign """
    expected_sign = []

    for sign in formula:
        if sign in SupportSign.symbols:
            continue
        if expected_sign and sign not in expected_sign:
            return False
        if sign in Negation.symbols:
            expected_sign = SentenceVariable.symbols
        elif sign in SentenceConjunction.symbols:
            expected_sign = Negation.symbols + SentenceVariable.symbols
        elif sign in SentenceVariable.symbols:
            expected_sign = SentenceConjunction.symbols

    return any(symbol in expected_sign for symbol in SentenceVariable.symbols)