from schwifty import IBAN, BIC
import datetime

def valid_iban(field, value, error):
    try:
        IBAN(value)
        return True
    except ValueError:
        error(field, 'not a valid IBAN')

def valid_bic(field, value, error):
    try:
        BIC(value)
        return True
    except ValueError:
        error(field, 'not a valid BIC')

def iso_date(field, value, error):
    try:
        datetime.datetime.strptime(value, "%Y-%m-%d")
        return True
    except ValueError:
        error(field, 'not a valid ISO 8601 date')

def valid_money_amount(field, value, error):
    try:
        # value is string, check formatting by parsing as float
        float(value)
        return True
    except (ValueError, TypeError):
        error(field, 'not a valid money value')