atmmanager.py

import json

class ATMApp:
    """Class ATM calls account information from a JSON file and manipulates it
    per commands given through an interface class. The JSON file is then updated
    to reflect transactional commands"""
    def __init__(self, accountfile, interface):
        """Creates a list of Users labeled self.users with which to manage account 
        information. Users can be sorted by userid when given the proper key."""
        with open(accountfile) as f:
            data = json.load(f)

        self.users = []
        for key, value in data['users'].items():
            user = User(value["userid"], value["pin"],value["checking"],value["savings"], value["name"])
            self.users.append(user)
        self.interface = interface
        self.run()
    
    def run(self):
        while not self.interface.close():
            self.screen1()
            self.screen2()

    def screen1(self):
        userid = None
        pin = None
        while not self.verify(userid, pin):
            userid, pin = self.interface.getUserInput()
        self.user = self.getUser(userid)

    def screen2(self):
        terminate = self.interface.close()
        while not terminate:
            checking, savings = self.user.checkBalances()
            tran_type = self.interface.chooseTransaction()
            self.__updateAccounts()
            if tran_type[0] == "C":
                self.interface.displayBalance(checking, savings)
            elif tran_type[0] == "W":
                value, account_type = self.interface.withdrawCash()
                self.user.exchangeCash(value, account_type)
            elif tran_type[0] == "T":
                inaccount, outaccount, value = self.interface.getTransferInfo()
                self.user.transferMoney(inaccount, outaccount, value)
            elif tran_type[0] == "S":
                recipient, type_sender, type_recipient, value = self.interface.getSendInfo()
                recipient = self.getUser(recipient)
                self.sendMoney(self.user, recipient, value, type_sender, type_recipient)
            elif tran_type[0] == "Q":
                self.user.exchangeCash(-100, "Checking")
            elif tran_type[0] == "E":
                self.__updateAccounts()
                terminate = True

    def getUser(self, userid):
        """Returns user object with given userid"""
        for user in self.users:
            if userid == user.getID():
                return user

    def sendMoney(self, sender, recipient, value, type_sender, type_recipient):
        #validate types as str "Checking" or "Savings"
        """Used to move money from one user to another. "sender" refers to the user
        itiating the transaction. "recipient" refers to the user recieving the transaction.
        "Value" should be negative to move money from sender to recipient. "type_" refers
        to the type of account being used eg. "Checking" or "Savings". """
        checking, savings = sender.checkBalances()
        checking, savings = recipient.checkBalances()
        sender.exchangeCash(-value, type_sender)
        recipient.exchangeCash(value, type_recipient)

    def __updateAccounts(self):
        data = {}
        data['users'] = {}
        for user in self.users:
            json_str = (vars(user))
            userid = user.getID()
            data['users'][userid] = json_str
        with open('new_atmusers.json', 'w') as f:
            json.dump(data, f, indent=4)

    def verify(self, userid, pin):
        for user in self.users:
            if (user.getID() == userid) and (user.getPIN() == pin):
                return True
        else:
            return False

class User:
    def __init__(self, userid, pin, checking, savings, name):
        self.userid = userid
        self.pin = pin
        self.checking = float(checking)
        self.savings = float(savings)
        self.name = name
    
    def checkBalances(self):
        """Returns two values, one for checking account balance, and 
        one for savings account balance"""
        return self.checking, self.savings
    
    def exchangeCash(self, value, inaccount):
        """Used to deposit or withdraw money from checking or savings accounts."""

        if inaccount[0] == "C":
            self.checking = round(self.checking + value, 2)
        else:
            self.savings = round(self.savings + value, 2)


    def transferMoney(self, inaccount, outaccount, value):
        ####Verify that inaccount and outaccount can only be savings or checking
        """Used to move money between checking and savings accounts within a single user."""
        if inaccount[0] == "C":
            self.checking = self.checking + value
            self.savings = self.savings - value
        else:
            self.checking = self.checking - value
            self.savings = self.savings + value
    
    def getID(self):
        """Returns userid"""
        return self.userid

    def getPIN(self):
        return self.pin