Imports System.Threading
Module Module1

    Dim firstName, lastName, phoneNumber, Address, Email, Password, Username As String
    Dim cardNumber, securityNumber As Integer
    Dim Balance As Decimal

    Public Function NewCardNumber()
        Dim num As String
        Dim CardNumTaken As Boolean = False
        Dim loopState = True

        While loopState = True
            loopState = False
            Randomize()
            cardNumber = Int(Rnd() * 99999999)

            Using file = My.Computer.FileSystem.OpenTextFileReader("C:\Database\CardNumbers.txt")
                Do
                    num = file.ReadLine()
                    If cardNumber = num Then
                        Console.WriteLine("Test")
                        CardNumTaken = True
                    End If

                    If CardNumTaken = True And num = "" Then
                        loopState = True
                        CardNumTaken = False
                    End If
                Loop Until num = "" And CardNumTaken = False
            End Using
        End While

        Using file = My.Computer.FileSystem.OpenTextFileWriter("C:\Database\CardNumbers.txt", True)
            file.WriteLine(cardNumber)
        End Using

        Return cardNumber

    End Function

    Sub CreateFile()

        Using file = My.Computer.FileSystem.OpenTextFileWriter("C:\Database\" & Username & ".txt", True)
            file.WriteLine(Password)
            file.WriteLine(cardNumber)
            file.WriteLine(securityNumber)
            file.WriteLine(Balance)
            file.WriteLine(firstName)
            file.WriteLine(lastName)
            file.WriteLine(Address)
            file.WriteLine(phoneNumber)
            file.WriteLine(Email)
        End Using

    End Sub

    Public Function CheckUser(ByVal user)
        Dim Found As Boolean
        For Each foundFile As String In My.Computer.FileSystem.GetFiles("C:\Database")
            If ("C:\Database\" & user & ".txt") = foundFile Then
                Found = True
                Return True
            End If
        Next

        If Found = False Then
            Return False
        End If

    End Function

    Sub Update(ByVal user, one, two, three, four, five, six, seven, eight, nine)
        My.Computer.FileSystem.DeleteFile("C:\Database\" & user & ".txt")
        Using file = My.Computer.FileSystem.OpenTextFileWriter("C:\Database\" & user & ".txt", True)
            file.WriteLine(one)
            file.WriteLine(two)
            file.WriteLine(three)
            file.WriteLine(four)
            file.WriteLine(five)
            file.WriteLine(six)
            file.WriteLine(seven)
            file.WriteLine(eight)
            file.WriteLine(nine)
        End Using
    End Sub

    Sub SendMoney(ByVal amount, ByVal user)
        Dim info(8)
        Balance -= amount
        Using contents = My.Computer.FileSystem.OpenTextFileReader("C:\Database\" & user & ".txt")
            For i = 0 To 8
                info(i) = contents.ReadLine()
            Next
        End Using

        info(3) += amount

        Update(user, info(0), info(1), info(2), info(3), info(4), info(5), info(6), info(7), info(8))

    End Sub

    Sub Deposit()
        Console.Write("This is where the ATM would input money. Instead write the amount: ")
        Balance += Console.ReadLine()
    End Sub

    Sub SignUp()
        Dim usernameIsFree As Boolean
        Do
            usernameIsFree = True

            Console.Write("Username (At least 8 characters) ")
            Username = Console.ReadLine()

            For Each foundFile As String In My.Computer.FileSystem.GetFiles("C:\Database")
                If ("N\Database\" & Username & ".txt") = foundFile Then
                    usernameIsFree = False
                    Console.WriteLine("Username Is taken.")
                End If
            Next

        Loop Until usernameIsFree = True And Username.Count() >= 8

        Do
            Console.Write("Password (At least 8 characters) ")
            Password = Console.ReadLine()
        Loop Until Password.Count() >= 8

        Console.Write("First Name ")
        firstName = Console.ReadLine()
        Console.Write("Last Name ")
        lastName = Console.ReadLine()
        Console.Write("Phone Number ")
        phoneNumber = Console.ReadLine()
        Console.Write("Address ")
        Address = Console.ReadLine()
        Console.Write("Email ")
        Email = Console.ReadLine()
        Randomize()
        securityNumber = Int(Rnd() * 999)
        Console.Write("Your security number Is {0}. Write it down And don't forget it.", securityNumber)
        Console.WriteLine("Your card number is {0}", NewCardNumber())
        CreateFile()

    End Sub

    Sub Login()
        Dim usernameExists As Boolean = False
        Dim info(8) As String

        Do
            usernameExists = False
            Console.Write("Username: ")
            Username = Console.ReadLine()

            For Each foundFile As String In My.Computer.FileSystem.GetFiles("C:\Database")
                If ("C:\Database\" & Username & ".txt") = foundFile Then
                    usernameExists = True
                End If
            Next

        Loop Until usernameExists = True

        Using contents = My.Computer.FileSystem.OpenTextFileReader("C:\Database\" & Username & ".txt")
            For i = 0 To 8
                info(i) = contents.ReadLine()
            Next
        End Using

        Password = info(0)
        cardNumber = info(1)
        securityNumber = info(2)
        Balance = info(3)
        firstName = info(4)
        lastName = info(5)
        Address = info(6)
        phoneNumber = info(7)
        Email = info(8)

        Dim tempPassword, tempSecurityNumber As String
        Dim attempts As Integer = 0

        Do
            attempts += 1
            Console.Write("Password (Attempt {0}/3): ", attempts)
            tempPassword = Console.ReadLine()
            If tempPassword = Password Then
                Console.WriteLine("Welcome!")
            ElseIf attempts = 3 Then
                Console.WriteLine("You've ran out of attempts and will be locked out for 5minutes.")
                System.Threading.Thread.Sleep(300000)
                attempts = 0
            Else
                Console.WriteLine("Please try again.")
            End If

        Loop Until tempPassword = Password

        Do
            Console.Write("Security Number (On back of the card or noted down): ")
            tempSecurityNumber = Console.ReadLine()
        Loop Until tempSecurityNumber = securityNumber

    End Sub

    Sub Main()
        Dim input, Send As Integer
        Dim user As String
        Dim runningState As Boolean = True
        Dim Proceed As Boolean = True

        While runningState = True
            Console.Clear()
            Console.WriteLine("Welcome to Jordan's the online banking application.")
            Console.Write("To login type 1, to signup type 2: ")

            Do
                input = Console.ReadLine()
                If input = 1 Then
                    Login()
                ElseIf input = 2 Then
                    SignUp()
                Else
                    Console.WriteLine("Incorrect input. Please try again.")
                End If
            Loop Until input = 1 Or input = 2

            Console.WriteLine("Welcome {0}, your balance is £{1}", firstName, Balance)
            Console.WriteLine("To deposit money press 1, to Send money press 2.")

            Do
                input = Console.ReadLine()
                If input = 1 Then
                    Deposit()
                    Console.WriteLine("Your new balance is £{0}. Thank you for using our ATM", Balance)
                ElseIf input = 2 Then
                    Do
                        Proceed = True
                        Console.Write("How much money do you want to send?: ")
                        Send = Console.ReadLine()
                        Console.Write("Whats the username of the person you want to send money to?: ")
                        user = Console.ReadLine()
                        If Send > Balance Or Send < 0.01 Then
                            Proceed = False
                            Console.WriteLine("Invalid amount.")
                        End If
                        If CheckUser(user) = False Then
                            Proceed = False
                            Console.WriteLine("Invalid username.")
                        End If
                    Loop Until Proceed = True
                    SendMoney(Send, user)
                    Console.WriteLine("Your new balance is £{0}. Thank you for using our ATM", Balance)
                Else
                    Console.WriteLine("Either 1 or 2.")
                End If

            Loop Until input = 1 Or input = 2
            Update(Username, Password, cardNumber, securityNumber, Balance, firstName, lastName, Address, phoneNumber, Email)
            System.Threading.Thread.Sleep(10000)
        End While
    End Sub

End Module