from datetime import datetime, timezone
from zoneinfo import ZoneInfo


def utc_now() -> datetime:
    return datetime.now(timezone.utc)


def to_utc_iso(value: datetime) -> str:
    return value.astimezone(timezone.utc).isoformat(timespec="seconds")


def parse_utc_iso(value: str) -> datetime:
    parsed = datetime.fromisoformat(value)
    if parsed.tzinfo is None:
        return parsed.replace(tzinfo=timezone.utc)
    return parsed.astimezone(timezone.utc)


def format_local_dt(value: str | datetime, tz: ZoneInfo) -> str:
    parsed = parse_utc_iso(value) if isinstance(value, str) else value
    return parsed.astimezone(tz).strftime("%Y-%m-%d %H:%M")