donation = max(Decimal('0'), (invoice.value - sum(rbi)))

    return donation.quantize(Decimal('.01'))

# TODO: include van/de/van der/de la/etc etc etc

@register.simple_tag

def name_split(name, split_characters=None):

    tokens = name.split()

    if split_characters is None or len(name) > split_characters:

        even_split = int((len(tokens) + 1) / 2)  # Round up.

    else:

        even_split = len(tokens)

    return {

        "first" : " ".join(tokens[:even_split]),

        "last" : " ".join(tokens[even_split:]),

    }

@register.simple_tag

def company_split(name):

    f =  name_split(name, 18)

    return f

CLEARED = set([

    "BeeWare Project",

    "Project Jupyter",

    "PSF Packaging WG / PyCon 2018 Chair",

    "PyCon Ukraine",

    "PyLadies PDX",

    "Recovered Silver",

    "Twisted",

    "@vmbrasseur",

])

@register.simple_tag

def affiliation(ticket, user):

    aff = user.attendee.attendeeprofilebase.attendeeprofile.company

    if "Individual" not in ticket or "Sponsor" in ticket:

        return aff

    elif ticket == "Individual Supporter" and aff in CLEARED:

        return aff

    else:

        return ""