scenario1.py

from datetime import datetime
from typing import Optional


class BankAccount:
    def __init__(self, owner: str, initial_balance: int):
        self.balance = initial_balance
        self.owner = owner

    def print(self):
        print(f"This account of {self.owner} has a balance of {self.balance}")

    def _credit(self, value: float, transaction_date: datetime):
        self.balance += value

    def transfer_to(self, recipient: "BankAccount", value: float, transaction_date: datetime):
        self.balance -= value
        recipient._credit(value, transaction_date)

class InsufficientBalance(ValueError):
    pass

class BlockedBankAccount(BankAccount):
    def transfer_to(self, recipient: "BankAccount", value: float, transaction_date: datetime):
        if self.balance < value:
            raise InsufficientBalance(f"{self.owner} does not have enough money")
        super().transfer_to(recipient, value, transaction_date)


class AgiosBankAccount(BankAccount):
    def __init__(self, owner: str, initial_balance: int, bank: "BankAccount"):
        self.bank = bank
        self.__negative_from: Optional[datetime] = None
        super().__init__(owner, initial_balance)

    def transfer_to(self, recipient: "BankAccount", value: float, transaction_date: datetime):
        if self.__negative_from is None and self.balance < value:
            self.__negative_from = transaction_date
        super().transfer_to(recipient, value, transaction_date)

    def _credit(self, value: float, transaction_date: datetime):
        super(AgiosBankAccount, self)._credit(value, transaction_date)
        if self.__negative_from is not None:
            agios_value = (transaction_date - self.__negative_from).days
            self.__negative_from = None
            self.transfer_to(self.bank, agios_value, transaction_date)


bank = BankAccount("LCL", 10000)
walmart = BlockedBankAccount("Walmart", 5000)
alice = BlockedBankAccount("Alice Worz", 500)
bob = AgiosBankAccount("Bob Müller", 100, bank)

try:
    #1.4.1. Alice buys $100 of goods at Walmart
    alice.transfer_to(walmart, 100, datetime(2022, 1, 1))
    #1.4.2. Bob buys $100 of goods at Walmart
    bob.transfer_to(walmart, 100, datetime(2022, 1, 2))
    #1.4.3. Alice makes a donation of $100 to Bob
    alice.transfer_to(bob, 100, datetime(2022, 1, 3))
    #1.4.4. Bob buys $200 at Walmart
    bob.transfer_to(walmart, 200, datetime(2022, 1, 4))

    alice.transfer_to(bob, 200, datetime(2022, 1, 9))
except InsufficientBalance:
    print("This scenario cannot be executed because of insufficient balance")

for account in [bank, walmart, alice, bob]:
    account.print()