Gilded rose hack

gistfile1.py

def update(item_original, attr, value):
    """
    Returns a new dict with attr=value
        item = {"name": "+5 Dexterity Vest", "sell_in": 10, "quality": 20}
        => {'sell_in': 10, 'quality': 20, 'name': '+5 Dexterity Vest'}
        update(item, 'quality', 5)
        => {'sell_in': 10, 'quality': 5, 'name': '+5 Dexterity Vest'}
    """
    item = item_original.copy()
    item[attr] = value
    return item


def enforce_range(quality):
    if quality < 0:
        return 0
    if quality > 50:
        return 50
    return quality


def backstage(quality, sell_in):
    conds = zip([0, 5, 10], [0, quality + 3, quality + 2])
    for (d, q) in conds:
        if sell_in <= d:
            return q
    return quality + 1


def double_rate(quality, sell_in, sign):
    if sell_in <= 0:
        return quality + 2 * sign
    else:
        return quality + 1 * sign


def aged_brie(quality, sell_in):
    return double_rate(quality, sell_in, 1)


def sulfuras(quality, sell_in):
    return quality


def decrease_quality(quality, sell_in):
    return double_rate(quality, sell_in, -1)


def decrease_sell_in(value):
    return value - 1


def update_quality(item):
    special_quality_cases = {
        "Backstage passes to a TAFKAL80ETC concert":
            lambda q, s: enforce_range(backstage(q, s)),
        "Aged Brie":
            lambda q, s: enforce_range(aged_brie(q, s)),
        "Sulfuras, Hand of Ragnaros":
            sulfuras,
    }
    if item['name'] in special_quality_cases:
        q = special_quality_cases[item['name']](item['quality'], item['sell_in'])
    else:
        q = enforce_range(decrease_quality(item['quality'], item['sell_in']))
    return q


def update_sell_in(item):
    special_sell_in_cases = {
        "Sulfuras, Hand of Ragnaros":
            lambda s: s
    }
    if item['name'] in special_sell_in_cases:
        d = special_sell_in_cases[item['name']](item['sell_in'])
    else:
        d = decrease_sell_in(item['sell_in'])
    return d


def update_single_item(item):
    q = update_quality(item)
    s = update_sell_in(item)
    return update(update(item, 'quality', q), 'sell_in', s)


def update_items(items):
    return [update_single_item(item) for item in items]