"""
Exercise 7.3 from "A primer on..."
Change the internal data structure of the Account class and
implement additional functionality. Main points:
1. Classes & protected attributes
2. Python standard Library - documentation
"""
from datetime import datetime

class BankAccountP:
    def __init__(self, first_name, last_name, number, balance):
        self._first_name = first_name
        self._last_name = last_name
        self._number = number
        init_trans = {'time':datetime.now(), 'amount': balance}
        self._transactions = [init_trans]

    def deposit(self, amount):
        deposit = {'time':datetime.now(), 'amount': amount}
        self._transactions.append(deposit)

    def withdraw(self, amount):
        withdrawal = {'time':datetime.now(), 'amount': -amount}
        self._transactions.append(withdrawal)

    def get_balance(self):   
        s = 0
        for t in self._transactions:
            s += t['amount']
        return s

    def print_info(self):
        first = self._first_name; last = self._last_name
        number = self._number; bal = self.get_balance()
        s = f'{first} {last}, {number}, balance: {bal}'
        print(s)

    def print_transactions(self):
        for t in self._transactions:
            """
            t['time'] is a datetime object, which has a
            method strftime which can be used to format the output. 
            See the online documentation for details. 
            """
            time = t['time'].strftime('%a %d %b %H:%M:%S') 
            amount = t['amount'] 
            print(f"Time: {time}, amount: {amount}")


a1 = BankAccountP('John', 'Olsson', '19371554951', 20000)
a2 = BankAccountP('Liz', 'Olsson',  '19371564761', 20000)
a1.deposit(1000)
a1.withdraw(4000)
a2.withdraw(10500)
a1.withdraw(3500)
print("a1's balance:", a1.get_balance())
a1.print_info()
a1.print_transactions()

"""
Terminal> python Account3.py 
a1's balance: 13500
John Olsson, 19371554951, balance: 13500
Time: Mon 21 Oct 17:44:28, amount: 20000
Time: Mon 21 Oct 17:44:28, amount: 1000
Time: Mon 21 Oct 17:44:28, amount: -4000
Time: Mon 21 Oct 17:44:28, amount: -3500
"""