from .money_amount import Money
from .money_format_data import CURRENCIES


def format_money(amount: Money) -> str:
    """Render a monetary amount as text.

    Not every currency has two decimal places: yen has none, Kuwaiti dinar has
    three. Dividing by 100 to display an amount is wrong about as often as it
    is right, so the precision comes from the currency table.
    """
    fmt = next((c for c in CURRENCIES if c.code == amount.currency), None)
    if fmt is None:
        raise ValueError('no formatting rules for currency "%s"' % (amount.currency,))

    negative = amount.minor < 0
    digits = str(abs(amount.minor)).rjust(fmt.digits + 1, "0")
    whole = digits[: len(digits) - fmt.digits]
    fraction = digits[len(digits) - fmt.digits :]

    grouped = ""
    for i, ch in enumerate(whole):
        if i > 0 and (len(whole) - i) % 3 == 0:
            grouped += fmt.group_separator
        grouped += ch

    number = grouped + fmt.decimal_separator + fraction if fmt.digits > 0 else grouped
    body = fmt.symbol + number if fmt.symbol_before else number + fmt.symbol
    return "-" + body if negative else body