#include <cmath>
#include <string>
#include <iostream>

using namespace std;
string Users[3];
string passwords[3];
int balances[3];
bool locked[3];
int currentUser;
int currentBalance;

int withdraw(int amountToWithdraw)
{
    return currentBalance - amountToWithdraw;
}

int deposit(int amountToDeposit)
{
    return currentBalance + amountToDeposit;
}

int checkBalance()
{
    return currentBalance;
}

int main()
{
    Users[0] = "User0";
    Users[1] = "User1";
    Users[2] = "User2";
    passwords[0] = "Password0";
    passwords[1] = "Password1";
    passwords[2] = "Password2";
    balances[0] = 0;
    balances[1] = 0;
    balances[2] = 0;
    locked[0] = false;
    locked[1] = false;
    locked[2] = false;
    string Username = "";
    int i = 0;
    bool isAuthenticated = false;
    cout << "Please login." << endl << "Username: ";
    cin >> Username;
    while (Username != Users[i])
    {
        for (i = 0; i < 3; i++)
        {
            if (Username == Users[i])
            {
                currentUser = i;
                break;
            }
        }
        if (Username == Users[i])
        {
            break;
        }
        cout << "Invalid Username! Try Again!" << endl;
        cin >> Username;
    }

    while (Username == Users[i])
    {
        for (int j = 0; j < 3; j++)
        {
            string passwordInput;
            cout << "Please Enter your Password for " << Username << endl << "Password: ";
            cin >> passwordInput;
            if (passwordInput == passwords[currentUser])
            {
                isAuthenticated = true;
                break;
            }
            else {
                cout << "Password Incorrect! You have " << 2 - j << " attempts remaining" << endl;
                continue;
            }
        }
        if (!(isAuthenticated))
        {
            locked[currentUser] = true;
            cout << "You have entered your password too many times and your account is now locked!" << endl;
            cout << "Please contact your local system administrator at 860-687-4097" << endl;
            cout << "Thank you, have a nice day" << endl;
            return 0;
        }
        else {
            break;
        }
    }

    cout << "Welcome to the University of Hartford Automated Teller Machine (ATM) " << Users[currentUser] << endl << "Please select an option from the ones listed below:" << endl;
    string userSelection;
    currentBalance = balances[currentUser];
    while (isAuthenticated)
    {
        cout << "Deposit Money (D)" << endl << "Withdraw Money (W)" << endl << "Check Balance (C)" << endl << "Exit (E)" << endl;
        cin >> userSelection;
        if (userSelection == "D")
        {
            int amountToDeposit;
            cout << "Enter how much money you'd like to deposit:" << endl;
            cin >> amountToDeposit;
            if (amountToDeposit > 0)
            {
                currentBalance = deposit(amountToDeposit);
                cout << "Amount successfully deposited! Your current balance is now: " << currentBalance << endl;
            }
            else
            {
                cout << "Improper amount entered please select another option." << endl;
            }
        }
        else if (userSelection == "W")
        {
            int amountToWithdraw;
            cout << "Enter how much money you'd like to withdraw:" << endl;
            cin >> amountToWithdraw;
            if (amountToWithdraw <= currentBalance)
            {
                currentBalance = withdraw(amountToWithdraw);
                cout << "Dispensing Money." << endl << "Your current balance is now: " << currentBalance << endl;
            }
            else
            {
                cout << "Improper amount entered please select another option." << endl;
            }
        }
        else if (userSelection == "C")
        {
            cout << "Your current balance is: " << checkBalance() << endl;
        }
        else if (userSelection == "E")
        {
            isAuthenticated = false;
            cout << "Thank you, have a great day " << Users[currentUser] << "!" << endl;
            break;
        }
        else {
            cout << "Input not recognized! Please try again." << endl;
        }
    }


    return 0;
}