nit Unit_Login;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls;

type
  TfrmLogin = class(TForm)
    lbledtUsername: TLabeledEdit;
    lbledtPassword: TLabeledEdit;
    btnEnter: TButton;
    Exit: TButton;
    procedure btnEnterClick(Sender: TObject);
    procedure ExitClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmLogin: TfrmLogin;

implementation
uses
 Unit_AddLogin,UnitStudent_menu,Unit_TeacherMenu;  //Allows access to the form add login and studnet menu
{$R *.dfm}

Type
TPassword = record    //creating a record for the file to store passwords.
Password : string[20];
end;

Type
TStudentNumber = record
StudentNumber : String[6];
end;

var
PasswordFile : File of Tpassword;    // This will be the file whch stores the usernames
StudentNumberFile : File of TStudentNumber;
New_Password : array [1..1000] of TPassword;       //An array used to store multiple Passwords
New_StudentNumber : array [1..1000] of TStudentNumber;
Path : String;

procedure TfrmLogin.btnEnterClick(Sender: TObject);
var
count,counter,I,Temp_num : integer;
Correct : Boolean;
CurrentFile : TextFile;
begin
  {Code to check if teacher is trying to login in to the system}
  if (lbledtusername.Text = 'David.Searle') and (lbledtPassword.Text = 'Tudor') then  //This is the hardcoded login detials for Mr Searl's account
      begin
      frmTeacherMenu.Show;      //Shows the form where the teacher can create new users
      end;

   AssignFile(PasswordFile ,Path +'Password.dat');   //assigns exsiting file to Passwordfile
   reset(PasswordFile );             //opens the file
   AssignFile(StudentNumberFile ,Path +'StudentNumber.dat');   //assigns exsiting file to StudentNumberFile
   reset(StudentNumberFile );
   count := 0;    //intialises count

   while not  eof (StudentNumberFile) and not Eof (passwordfile) do
   {This will repeat the code below untill the end of file is reached}
    begin
      count := count + 1;
      Read(Passwordfile,New_Password[count]);  //reads the password from Passwordfile
      Read(StudentNumberFile,New_StudentNumber[count]);

      if ((lbledtusername.Text = New_StudentNumber[count].StudentNumber)  and
      (lbledtPassword.Text = New_Password[count].Password)) then
       begin
        frmStudentmenu.Show;   //if the login credentials is correct it shows the student menu
       end;
    end;
    CloseFile(Passwordfile);  //Closes file which contains passwords
    CloseFile(StudentNumberFile);
   {Code to output incorrect login}
    I := 0;
   for counter  := 1 to count do
    begin
      I := I + 1;
      if (lbledtusername.Text = New_StudentNumber[I].StudentNumber) and
       (lbledtPassword.Text = New_Password[I].Password)  then
       begin
        Temp_num:= I;
       end;
      end;

      Correct := True;
      if ((lbledtusername.Text <> New_StudentNumber[temp_num].StudentNumber)) then
          begin
            Correct := False;
          end;

   //This checks that the user enters either teacher or student login
  if  ((Correct = False)  and
      (lbledtPassword.Text <> New_Password[temp_num].Password)) and ((lbledtusername.Text <>
       'David.Searle')or (lbledtPassword.Text <> 'Tudor')) or (lbledtPassword.Text = '') or
       (lbledtUsername.Text = '')then
         begin
          Showmessage('Incorrect Login');
         end;

   AssignFile(CurrentFile,'CurrentUser.txt');    //assigns exsiting file to New_usernamefile
   ReWrite(CurrentFile);                       //opens the file
   Writeln(CurrentFile,New_StudentNumber[Temp_num].StudentNumber);
   Writeln(CurrentFile,New_Password[Temp_num].Password);
   CloseFile(CurrentFile);





end;



procedure TfrmLogin.ExitClick(Sender: TObject);
begin
  close;
end;

procedure TfrmLogin.FormCreate(Sender: TObject);
var
count : integer;
begin
  Count := Count + 1;
  if Count = 1 then
   begin
    Path := GetCurrentDir;
    Count := 2;
   end;

end;

end.