using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace atm {
    class ATM {

        const int SAVING_ACCOUNT = 1;
        const int DEBIT_CARD = 2;
        const int CREDIT_CARD = 3;
        const int LINE_OF_CREDIT = 4;
        static double[] accountBalances = { 0.0, 901.45, 450.0, 1500.0, 2000.0 };
        static string[] accountTypes = { "", "Savings Account", "Debit Card", "Credit Card",
                                       "Line of Credit Account" };

        static void Main(string[] args) {
            while (true) {
                Console.WriteLine("Welcome to Sam's ATM Simulator \n       Transaction Menu");
                Console.WriteLine("       ================\n       1. Check Balance\n       2. Withdrawal");
                Console.Write("       3. Transfer\n\n\nPlease Enter your choice 1 ... 3 or 0 to exit:  ");
                string input = Console.ReadLine();
                if (input == "1") CheckBalanceMain();
                else if (input == "2") WithdrawalMain();
                else if (input == "3") TransferMain();
                else if (input == "0") Environment.Exit(0);
                else Console.WriteLine("You pressed an invalid character! Try again.\n\n");

            }
        }

        static void CheckBalanceMain() {
            Console.WriteLine("\n\n       1. Savings Account\n       2. Debit Card\n       3. Credit Card");
            Console.Write("       4. Line of Credit\n       \nPlease Enter your choice 1 ... 4 or 0 to return:  ");
            string input = Console.ReadLine();
            int whichAccount = Convert.ToInt32(input);
            if (whichAccount > 0) DisplayBalance(whichAccount);
            else Main(new String[0]);
        }


        static void DisplayBalance(int whichAccount) {
            Date();
            Console.WriteLine("\n\nBalance of {0} is {1}\n",
                              accountTypes[whichAccount], accountBalances[whichAccount]);
            Main(new String[0]);
        }

        static void Date() {
            DateTime date = DateTime.Now;
            Console.WriteLine("Current Date: {0} ", date);
        }

        static void WithdrawalMain() {
            Console.WriteLine("\n\n       1. Savings Account\n       2. Debit Card\n       3. Credit Card");
            Console.Write("       4. Line of Credit\n       \nPlease Enter your choice 1 ... 4 or 0 to return:  ");
            string input = Console.ReadLine();
            int whichAccount = Convert.ToInt32(input);
            if (whichAccount > 0) WithdrawAmount(whichAccount);
        }

        static void WithdrawAmount(int whichAccount) {
            Console.WriteLine("Please enter amount to withdraw: "); double amount = Convert.ToDouble(Console.ReadLine());
            // Checks if amount is a a multiple of 10, and is not 10 or 30 (because you can have any odd multiple of 10, but ONLY if it above 30
            if (amount % 10 == 0 & amount != 10 & amount != 30)
            {
                if ((accountBalances[whichAccount]) - amount < 10) {
                    Console.WriteLine("There are insufficient funds in {0}", accountTypes[whichAccount]); WithdrawAmount(whichAccount);
                } else {
                    if (accountTypes[whichAccount] == "Debit Card" || accountTypes[whichAccount] == "Credit Card") accountBalances[whichAccount] -= 0.10;
                    accountBalances[whichAccount] -= amount; DispenseCash(amount, whichAccount);
                }
            } else {
                //since we're calling this again we dont want the arithmatic to be calculated twice
                Console.WriteLine(" {0} cannot be dispensed.", amount); WithdrawAmount(whichAccount);

            }
        }

        static void DispenseCash(double amount, int whichAccount) {
            int numlargenotes = (int)amount / 50;
            int numsmallnotes = 0;
            //a temporary variable, as we can't declare it in an if statement
            if (amount % 50 == 10 || amount % 50 == 30) {
                numlargenotes = numlargenotes - 1;
                numsmallnotes = (int)(amount - (50 * numlargenotes)) / 20;
            } else
                numsmallnotes = (int)amount % 50 / 20;

            Console.WriteLine("\nPlease collect ${0} consisting of:\n{1} $50.00 notes and {2} $20.00 notes.\n",
                            amount, numlargenotes, numsmallnotes);
            Date();
            Console.WriteLine("Balance of {0} is {1}.\n", accountTypes[whichAccount], accountBalances[whichAccount]);
        }

        static void TransferMain() {
            Console.WriteLine("\n       1. Savings Account\n       2. Debit Card\n       2. Debit Card");
            Console.WriteLine("       3. Credit Card\n       4. Line of Credit\n");
            Console.WriteLine("Transfer from which account?   ");
            Console.Write("Please Enter your choice 1 ... 4 or 0 to return:  ");
            int fromAccount = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("\nTransfer to which account?");
            Console.Write("Please Enter your choice 1 ... 4 or 0 to return:  ");
            int toAccount = Convert.ToInt32(Console.ReadLine());
            if (fromAccount > 0 & toAccount > 0)
                if (fromAccount == toAccount) Console.WriteLine("Must select two different accounts");
                else TransferAmount(fromAccount, toAccount);
        }

        static void TransferAmount(int fromAccount, int toAccount) {
            Console.Write("Please enter amount to Transfer: ");
            string input = Console.ReadLine();
            double amount = Convert.ToDouble(input);
            if (accountBalances[fromAccount] - accountBalances[toAccount] < 10)
                Console.WriteLine("Insufficient Funds to complete transaction");
            else {
                accountBalances[fromAccount] = accountBalances[fromAccount] - amount - 0.5;
                accountBalances[toAccount] = accountBalances[toAccount] + amount;
                Console.WriteLine("Transaction was successful.\n");
                Date();
                Console.WriteLine("Balance of {0} is {1}", accountTypes[fromAccount], accountBalances[fromAccount]);
                Console.WriteLine("Balance of {0} is {1}", accountTypes[toAccount], accountBalances[toAccount]);
            }

        }
    }
}