# See extensive tutorial here https://docs.python.org/3/library/sqlite3.html

import time
import sqlite3
import sys


def get_balance(cur: sqlite3.Cursor, usr: str) -> float:
    res = cur.execute("SELECT balance FROM acc WHERE usr=?", [usr])
    row = res.fetchone()
    b = row[0]
    return b


def set_balance(cur: sqlite3.Cursor, usr: str, b1: float) -> None:
    cur.execute("""
      UPDATE acc
      SET balance = ?
      WHERE usr=?
    """, [b1, usr])


def main() -> None:
    con = sqlite3.connect("bank.db", autocommit=True)

    cur = con.cursor()

    res = cur.execute("SELECT * FROM acc")

    answ = res.fetchall()

    print(answ)

    usr = input("Enter the user name: ")
    res = cur.execute("SELECT * FROM acc WHERE usr=?", [usr])
    if res.fetchone() is None:
        print("Wrong user. Exit")
        sys.exit()

    while True:
        try:
            print()
            print()
            cmd = input(usr + ": (b)alance/(d)eposit/(w)ithdraw/"
                        "(t)ransfer/(q)uit: ")
            if cmd == "b":
                b = get_balance(cur, usr)
                print("Your balance is ", b)
            elif cmd == "d":
                amount = input(usr + ": insert cash or check into the machine."
                               " Amount: ")
                a = float(amount)
                b = get_balance(cur, usr)
                b1 = b+a
                set_balance(cur, usr, b1)
                print(usr + ": your new balance is ", b1)
            elif cmd == "w":
                amount = input(usr + ": how much? ")
                a = float(amount)
                b = get_balance(cur, usr)
                if a > b:
                    print("ERROR: INSUFFICIENT FUNDS!!")
                else:
                    for x in range(4):
                        print("***DISPENSING MONEY TO "+usr+" NOW***")
                        time.sleep(1)
                    b1 = b-a
                    set_balance(cur, usr, b1)
                    print(usr+": your new balance is ", b1)
            elif cmd == "t":
                amount = input(usr + ": how much do you transfer? ")
                a = int(amount)
                b = get_balance(cur, usr)
                if a > b:
                    print("ERROR: INSUFFICIENT FUNDS!!")
                else:
                    usrt = input(usr+": to whom do you transfer? ")
                    bt = get_balance(cur, usrt)
                    b1 = b-a
                    bt1 = bt+a
                    set_balance(cur, usr, b1)
                    set_balance(cur, usrt, bt1)
                    print(usr + ": your new balance is ", b1)
                    print(usrt + ": your new balance is ", bt1)
            elif cmd == "q":
                sys.exit()
        except EOFError:
            sys.exit()


if __name__ == '__main__':
    main()