# -*- coding: utf-8 -*-


import arrow

TIME_FMT = "YYYYMMDDHHmmss"


def get_time_str(
        delta: int = 0, flag: str = "now", fmt: str | None = TIME_FMT
) -> str:
    """
    Return a Beijing time strings.
    :param delta: time delta(seconds)
    :param flag:
    :param fmt: time string's format
    :return: a '%Y%m%d%H%M%S' format strings
    """
    utc = arrow.utcnow()
    local = utc.to("Asia/Shanghai")
    if flag == "ago":
        delta = -delta
        t = local.shift(seconds=delta)
    elif flag == "later":
        t = local.shift(seconds=delta)
    else:
        t = local

    time_str = t.format(fmt)

    return time_str


def get_quarter_minutes(time_str: str) -> str:
    temp = arrow.get(time_str, TIME_FMT).timestamp() // (15 * 60) * (15 * 60)
    return arrow.get(temp).time().strftime("%H%M%S")