from __future__ import annotations


def normalize_googlechat_target(raw: str) -> str | None:
    if not raw:
        return None
    t = raw.strip()
    for prefix in ("googlechat:", "google-chat:", "gchat:"):
        if t.lower().startswith(prefix):
            t = t[len(prefix):]
            t = t.strip()
            break
    if t.lower().startswith("user:users/"):
        t = t[5:]
    elif t.lower().startswith("space:spaces/"):
        t = t[6:]
    if "@" in t and not t.startswith("users/") and not t.startswith("spaces/"):
        t = f"users/{t.lower()}"
    return t


def strip_message_suffix(target: str) -> str:
    idx = target.find("/messages/")
    return target[:idx] if idx != -1 else target


async def resolve_outbound_space(account, target: str) -> str | None:
    from yuxi.channel.extensions.googlechat.api import find_direct_message

    normalized = normalize_googlechat_target(target)
    if not normalized:
        return None
    base = strip_message_suffix(normalized)
    if base.startswith("spaces/"):
        return base
    if base.startswith("users/"):
        return await find_direct_message(account, base)
    return None


def is_space_target(target: str) -> bool:
    return target.startswith("spaces/")


def is_user_target(target: str) -> bool:
    return target.startswith("users/")