matemat/matemat/db/primitives/Transaction.py

from typing import Optional

from datetime import datetime

from matemat.db.primitives import User
from matemat.util.currency_format import format_chf


class Transaction:
    """
    Representation of a generic transaction involving an user and an amount of money.

    :param _id: The transaction ID in the database.
    :param user: The user affected by this transaction.
    :param value: The monetary value of this transaction.
    :param old_balance: The balance on the user's account before this transaction.
    :param date: The date of this transaction.
    """

    def __init__(self, _id: int, user: User, value: int, old_balance: int, date: datetime) -> None:
        self.id: int = _id
        self.user: User = user
        self.value: int = value
        self.old_balance: int = old_balance
        self.date: datetime = date

    @property
    def receipt_date(self) -> str:
        if self.date == datetime.fromtimestamp(0, UTC):
            return '<unknown>        '
        date: str = self.date.strftime('%d.%m.%Y, %H:%M')
        return date

    @property
    def receipt_value(self) -> str:
        value: str = format_chf(self.value, with_currencysign=False, plus_sign=True).rjust(8)
        return value

    @property
    def receipt_description(self) -> str:
        return 'Unidentified transaction'

    @property
    def receipt_message(self) -> Optional[str]:
        return None

    def __eq__(self, other) -> bool:
        if not isinstance(other, Transaction):
            return False
        return self.id == other.id and \
            self.user == other.user and \
            self.value == other.value and \
            self.old_balance == other.old_balance and \
            self.date == other.date

    def __hash__(self) -> int:
        return hash((self.id, self.user, self.value, self.old_balance, self.date))


class Consumption(Transaction):
    """
    Representation of a consumption involving an user, a product and an amount of money.

    :param _id: The transaction ID in the database.
    :param user: The user affected by this transaction.
    :param value: The (negative) price of the product that was bought.
    :param old_balance: The balance on the user's account before this transaction.
    :param date: The date of this transaction.
    :param product: The name of the product that was bought.
    """

    def __init__(self, _id: int, user: User, value: int, old_balance: int, date: datetime, product: str) -> None:
        super().__init__(_id, user, value, old_balance, date)
        self.product: str = product

    @property
    def receipt_description(self) -> str:
        return self.product

    def __eq__(self, other) -> bool:
        if not isinstance(other, Consumption):
            return False
        return super().__eq__(other) and \
            self.product == other.product

    def __hash__(self) -> int:
        return hash((super().__hash__(), self.product))


class Deposit(Transaction):
    """
    Representation of a deposit involving an user and an amount of money.

    :param _id: The transaction ID in the database.
    :param user: The user affected by this transaction.
    :param value: The amount of money that was deposited on the account.
    :param old_balance: The balance on the user's account before this transaction.
    :param date: The date of this transaction.
    """

    def __init__(self, _id: int, user: User, value: int, old_balance: int, date: datetime) -> None:
        super().__init__(_id, user, value, old_balance, date)

    @property
    def receipt_description(self) -> str:
        return 'Deposit'

    def __eq__(self, other) -> bool:
        if not isinstance(other, Deposit):
            return False
        return super().__eq__(other)

    def __hash__(self) -> int:
        return super().__hash__()


class Modification(Transaction):
    """
    Representation of a administrative account balance modification.  Involves the affected user, the agent that
    performed the modification and optionally a message for the reason of the modification.

    :param _id: The transaction ID in the database.
    :param user: The user affected by this transaction.
    :param value: The amount of money that was deposited on the account.
    :param old_balance: The balance on the user's account before this transaction.
    :param date: The date of this transaction.
    :param agent: The username of the agent performing the modification.
    :param reason: The reason for this modification, as provided by the agent.
    """

    def __init__(self,
                 _id: int,
                 user: User,
                 value: int,
                 old_balance: int,
                 date: datetime,
                 agent: str,
                 reason: Optional[str]) -> None:
        super().__init__(_id, user, value, old_balance, date)
        self.agent: str = agent
        self.reason: Optional[str] = reason

    @property
    def receipt_description(self) -> str:
        return f'Balance modified by {self.agent}'

    @property
    def receipt_message(self) -> Optional[str]:
        if self.reason is None:
            return None
        else:
            return f'Reason: «{self.reason}»'

    def __eq__(self, other) -> bool:
        if not isinstance(other, Modification):
            return False
        return super().__eq__(other) and \
            self.agent == other.agent and \
            self.reason == other.reason

    def __hash__(self) -> int:
        return hash((super().__hash__(), self.agent, self.reason))