def user_cart_checkout(_id):
users = mongo.db.users
items = mongo.db.items
user = users.find_and_modify(
{'_id': _id, 'trading': False},
{'$set': {'cart': []}},
fields={'cart': 1, 'items': 1},
)
if not user or not user.get('cart'):
return False, 'no cart or user is trading'
cart = user.get('cart', {})
item_count = len(user.get('items', {}))
if item_count > ITEM_LIMIT:
return
previous_gold = mongo.db.users.find_one(
{'_id': _id}, {'credits': 1}
).get('credits', 0)
# add items back to cart if we don't end up checking out
errors = []
added = []
for item in cart:
item_count += 1
if item_count > ITEM_LIMIT:
return
query = {
'class_id': item['class_id'],
'instance_id': item['instance_id'],
}
item = lookup_single(query)
if item:
price = item.get('price')
if not price:
errors.append((item, 'no price set'))
continue
short_keys = {
'app_id', 'context_id',
'class_id', 'instance_id',
}
short_item = {}
for key in short_keys:
short_item[key] = item[key]
# subtract money from user
old = users.find_and_modify(
{'_id': _id, 'credits': {'$gte': price}},
{'$inc': {'credits': -price}},
fields={'inventory': 0},
)
if not old:
# couldn't afford it
errors.append((item, 'not enough gold'))
continue
# modify stock available
query = short_item.copy()
query.update({'available': {'$gt': 0}})
old = items.find_and_modify(query, {'$inc': {'available': -1}})
if not old:
# not enough of item available, refund money
users.update({'_id': _id}, {'$inc': {'credits': price}})
errors.append((item, 'out of stock'))
continue
# TODO: adjust hotness here
# add to the user's item pool
users.update(
{'_id': _id},
{'$push': {'items': short_item}},
)
# add the price back in so we'll have it for the ledger
short_item['price'] = price
added.append(short_item)
# TODO: do something with errored items here?
mongo.db.ledger.insert({
'user_id': _id,
'items': added,
'change': -sum(item['price'] for item in added),
'previous': previous_gold,
'time': time.time(),
})
return True, 'success'
