from marko.block import BlockElement
from marko.source import Source
from re import Match, compile as re_compile


_LISTING_FLAG_RE = re_compile(r"(?i)(?:^|\s)\+?listing\b")


class Caption(BlockElement):
    """Represents caption element

    Syntax: %label Caption text [+listing]
    """

    pattern = r"\%(\w+)( (.+))?"

    def __init__(self, match: Match[str]):
        self.unique_name = match.group(1)
        raw = (match.group(3) or "").strip()
        self.with_listing = bool(_LISTING_FLAG_RE.search(raw))
        if self.with_listing:
            raw = _LISTING_FLAG_RE.sub(" ", raw).strip()
        self.text = raw or None

    @classmethod
    def match(cls, source: Source) -> Match[str] | None:
        return source.expect_re(cls.pattern)

    @classmethod
    def parse(cls, source: Source) -> Match[str] | None:
        m = source.match
        source.consume()
        return m