def create(self, source, target, date, amount, description=''):
if source is None:
raise TypeError('source Account is None.')
if target is None:
raise TypeError('target is None')
if source.key() == target.key():
raise ValueError('source and target Accounts are the same.')
# TODO: calculate exchange rate between account's currencies
exchange_rate = 1.0
app.logger.debug(source)
app.logger.debug(target)
app.logger.debug(date)
app.logger.debug(amount)
app.logger.debug(description)
app.logger.debug(exchange_rate)
transaction = Transaction(source=source, target=target, date=date, amount=amount,
exchange_rate=exchange_rate, description=description)
transaction.put()
# XXX: precision problems?
reverse_amount = exchange_rate * amount
reverse_rate = 1 / exchange_rate
reverse = Transaction(source=target, target=source, date=date, amount=reverse_amount,
exchange_rate=reverse_rate, description=description, reverse=transaction)
reverse.put()
transaction.reverse = reverse
transaction.put()
return transaction
