def invoke(
self,
currency: Currency,
amount: Decimal,
user: User,
user_currency: UserCurrency,
) -> UserCurrency:
if user_currency is None:
raise UsersDALException('You don`t have this currency at all')
if user_currency.amount < amount:
raise UsersDALException(
f'You have {user_currency.amount} but want to sell {amount}')
user_currency.amount -= amount
user.money += currency.selling_price * amount
return user_currency
def get_user_operations_history(
user_id: int,
operation_type: Optional[OperationType] = None,
size: Optional[int] = None,
page: Optional[int] = None,
) -> List[AbstractSerialize]:
with create_session() as session:
check_user_existence_and_get_if_exists(user_id, session)
operations_query: Query = session.query(Operation).filter(
Operation.user_id == user_id)
if operation_type is not None:
operations = operations_query.filter(
Operation.operation_type == operation_type).all()
else:
operations = operations_query.all()
if operations is None:
raise UsersDALException(
'Cannot find operations with this parameters')
if size is None and page is not None or size is not None and page is None:
raise PaginationError('size or page not stated')
if size is not None and page is not None:
operations = MyPagination.get_pagination(
operations, page, size)
res = []
for operation in operations:
res.append(serialize(operation))
return res
def get_currency(user_id: int, currency_id: int) -> AbstractSerialize:
with create_session() as session:
res = session.query(UserCurrency).filter(
UserCurrency.user_id == user_id,
UserCurrency.currency_id == currency_id).first()
if not res:
raise UsersDALException()
return serialize(res)
def get_user_by_name(user_name: str) -> AbstractSerialize:
with create_session() as session:
try:
user = session.query(User).filter(
User.login == user_name).one()
return serialize(user)
except NoResultFound:
raise UsersDALException()
def add_user(login: str) -> AbstractSerialize:
with create_session() as session:
if session.query(User).filter(User.login == login).first() is None:
u = User(login=login, money=settings.start_money)
session.add(u)
session.flush()
return serialize(u)
raise UsersDALException(Message.USER_ALREADY_CREATED.value)
def make_operation_with_currency(
user_id: int,
currency_id: int,
operation: OperationType,
amount: Decimal,
time: datetime,
) -> AbstractSerialize:
with create_session() as session:
currency: Currency = session.query(Currency).filter(
Currency.id == currency_id).first()
if currency is None:
raise UsersDALException('currency does not exist')
user = check_user_existence_and_get_if_exists(user_id, session)
check_course_changes(currency.modified_at, time)
user_currency: UserCurrency = session.query(UserCurrency).filter(
UserCurrency.user_id == user_id,
UserCurrency.currency_id == currency_id).first()
if amount <= 0:
raise UsersDALException('Invalid amount')
os = OperationStrategy()
if operation == OperationType.BUY:
os.set_strategy(Buy())
else:
os.set_strategy(Sell())
user_currency = os.invoke(currency, amount, user, user_currency)
session.add(user_currency)
session.flush()
copy = deepcopy(user_currency)
if user_currency.amount == 0:
session.delete(user_currency)
operation = Operation(
user_id=user_id,
currency_id=currency_id,
operation_type=operation,
amount=amount,
time=datetime.now(),
)
session.add(operation)
return serialize(copy)
def invoke(
self,
currency: Currency,
amount: Decimal,
user: User,
user_currency: UserCurrency,
) -> UserCurrency:
money_change = currency.purchasing_price * amount
if user.money < money_change:
raise UsersDALException('You dont have money to make operation')
user.money -= money_change
if user_currency is None:
user_currency = UserCurrency(user_id=user.id,
currency_id=currency.id,
amount=amount)
else:
user_currency.amount += amount
return user_currency
def check_course_changes(last_change_time: datetime,
last_time_when_course_was_known: datetime) -> None:
if last_time_when_course_was_known < last_change_time:
raise UsersDALException('currency price was change, check new price')
if last_time_when_course_was_known > datetime.now():
raise UsersDALException('too early time')
def check_user_existence_and_get_if_exists(user_id: int,
session: Session) -> User:
user = session.query(User).filter(User.id == user_id).first()
if user is None:
raise UsersDALException('User does not exists')
return user