import re

MAX_MESSAGE_CHARS = 12_000


def is_owner(user_id: int | None, owner_id: int) -> bool:
    return user_id is not None and user_id == owner_id


def is_allowed_chat(chat_id: int, chat_type: str, project_group_id: int, owner_id: int) -> bool:
    return chat_id == project_group_id or (chat_type == "private" and chat_id == owner_id)


def redact_for_logs(text: str) -> str:
    return f"<redacted:{len(text)} chars>"


def clean_user_text(text: str) -> str:
    return text.strip()[:MAX_MESSAGE_CHARS]


def safe_filename(name: str) -> str:
    return re.sub(r"[^A-Za-z0-9._-]", "_", name).strip(".") or "attachment"