def compute_balance(cls, users_expenses, month, year):
if len(users_expenses) == 0:
# nothing to do
return
user_a = users_expenses[0]
if len(users_expenses) == 2:
user_b = users_expenses[1]
else:
user_b = UserExpenses(users_helper.get_other_nickname())
debt = (user_a.totalcommon - user_b.totalcommon) / 2 + user_a.totaladvance - user_b.totaladvance
if user_a.totaltax != 0.0 or user_b.totaltax != 0.0:
debt += cls.compute_tax_balance(user_a, user_b, year)
if debt > 0:
min_user = user_b
max_user = user_a
else:
debt = -debt
min_user = user_a
max_user = user_b
# update the balance in DataStore
query = Balance.query(Balance.month == month, Balance.year == year)
balance = query.get()
if balance is None:
balance = Balance()
balance.year = year
balance.month = month
balance.debtor = min_user.user
balance.incredit = max_user.user
balance.amount = debt
balance.put()
return {'year': year, 'month': month, 'maxuser': max_user.user, 'minuser': min_user.user, 'debt': debt}
