import re

from cross.tokens import LinkToken, TextToken, Token


MFM_PATTERN = re.compile(r"\$\[([^\[\]]+)\]")


def strip_mfm(tokens: list[Token]) -> tuple[list[Token], bool]:
    modified = False
    original: str | None

    for tk in tokens:
        if isinstance(tk, TextToken):
            original = tk.text
            cleaned = __strip_mfm(original)
            if cleaned != original:
                modified = True
                tk.text = cleaned or ""

        elif isinstance(tk, LinkToken):
            original = tk.label
            cleaned = __strip_mfm(original)
            if cleaned != original:
                modified = True
                tk.label = cleaned

    return tokens, modified


def __strip_mfm(text: str | None) -> str | None:
    if text is None:
        return None

    def match_contents(match: re.Match[str]):
        content = match.group(1).strip()
        parts = content.split(" ", 1)
        return parts[1] if len(parts) > 1 else ""

    while MFM_PATTERN.search(text):
        text = MFM_PATTERN.sub(match_contents, text)

    return text