def has_tag(obj, key, category):
    return obj.tags.get(key=key, category=category) is not None;


def fmt_light(message):
    return "|r\u2600|y {} |r\u2600|n".format(message)


def fmt_dark(message):
    return "|w\u2600|=h {} |w\u2600|n".format(message)


def toggle_effect(obj, effect):
    if has_tag(obj, effect, "effect"):
        obj.tags.remove(effect, category="effect")
    else:
        obj.tags.add(effect, category="effect")


def has_effect(obj, effect):
    return has_tag(obj, effect, "effect")


def has_effect_in(obj, effects):
    return any(True for effect in effects if has_tag(obj, effect, "effect"))


def indefinite_article(name):
    """Return the right english indefinite article for given name."""
    the_vowels = ["a","e","i","o","u"]
    value = ""
    if name[0].lower() in the_vowels:
        value = "an"
    else:
        value = "a"

    return value