from __future__ import annotations


def format_privmsg_line(target: str, text: str) -> str:
    return f"PRIVMSG {target} :{text}"


def format_action_line(target: str, text: str) -> str:
    return f"PRIVMSG {target} :\x01ACTION {text}\x01"


def format_pong(token: str) -> str:
    return f"PONG :{token}"


def format_cap_req(capabilities: list[str]) -> str:
    return f"CAP REQ :{' '.join(capabilities)}"


def find_utf8_cut(encoded: bytes, byte_limit: int) -> int:
    cut = byte_limit
    while cut > 0 and (encoded[cut - 1] & 0xC0) == 0x80:
        cut -= 1
    while cut > 0 and (encoded[cut - 1] & 0xC0) == 0xC0:
        cut -= 1
    if cut == 0:
        cut = max(1, byte_limit)
    return cut