reverse_in_parentheses

#!/usr/bin/env python3

"""
Return the string with reversing parts inside parentheses.

Solution for problem from CodeSignal.
"""


def reverse_in_parentheses(s: str, is_reverse: bool = False) -> str:
    """
    s must be well-formed.
    """
    j = s.find('(')
    if j == -1:
        return (''.join(reversed(s)) if is_reverse
                else s)

    pieces = []
    count = 0
    i = 0
    while j < len(s):
        if s[j] == '(':
            if count == 0:  # add part without parentheses
                pieces.append(reverse_in_parentheses(s[i:j], is_reverse))
                i = j
            count += 1
        elif s[j] == ')':
            count -= 1
            if count == 0:  # add '...' from part '(...)'
                piece = reverse_in_parentheses(
                    reverse_in_parentheses(s[i + 1:j], True),
                    is_reverse)
                pieces.append(piece)
                i = j + 1

        j += 1

    pieces.append(reverse_in_parentheses(s[i:j], is_reverse))  # add remain

    return ''.join(reversed(pieces) if is_reverse
                   else pieces)


def main() -> None:
    datas = (
        ('abc', 'abc'),
        ('(bar)', 'rab'),
        ('foo(bar)baz', 'foorabbaz'),
        ('foo(bar)baz(blim)', 'foorabbazmilb'),
        ('foo(bar(baz))blim', 'foobazrabblim'),
        ('', ''),
        ('()', ''),
        ('(abc)d(efg)', 'cbadgfe'),
        ('((ab)cd)', 'dcab'),
        ('foo(bar(baz))blim', 'foobazrabblim')
    )

    for data_input, data_output in datas:
        print(f'"{data_input}" "{data_output}"', end=' ')
        result = reverse_in_parentheses(data_input)
        print(f'"{result}"')

        assert data_output == result


if __name__ == '__main__':
    main()