unit Playfair;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Grids, ComCtrls,About, Buttons, ExtCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    grid: TStringGrid;
    Edit1: TEdit;
    Edit3: TEdit;
    Edit2: TEdit;
    Edit4: TEdit;
    Button2: TButton;
    cb_hlg: TComboBox;
    cb_dummy: TComboBox;
    cb_geser: TComboBox;
    cb_tabel: TComboBox;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    Label7: TLabel;
    Label8: TLabel;
    Label9: TLabel;
    CheckBox1: TCheckBox;
    CheckBox2: TCheckBox;
    BitBtn1: TBitBtn;
    Label10: TLabel;
    Image1: TImage;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure cb_tabelChange(Sender: TObject);
    procedure Edit1Change(Sender: TObject);
    procedure Edit4Change(Sender: TObject);
    procedure Edit2Change(Sender: TObject);
    procedure cb_hlgChange(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  pjg_plain,pjg_key,pjg_cip,kol1,bar1,kol2,bar2,geser : integer;
  c,dum_c,X1,X2,HasilEnkrip,HasilDekrip : string;
  Key,PlainT,CipherT,Ekstrak,List_Huruf : string;

implementation

{$R *.dfm}

//-----fungsi Uppercase string
function Upper(s:string):string;
var i:byte;
begin
 for i:=1 to length(s) do
  s[i]:=upcase(s[i]);
  result :=s;
 end;
//---------------------------------

//-----Ekstrak Kunci-----------
function EkstrakKunci(e_key:string;var pjg:integer) : string;
var i,j:integer;
Hasil : string;
isi_key : char;
begin
  for i:=1 to pjg do
  begin
    isi_key:=e_key[i];
    if not (isi_key=#32) then
      for j:=i+1 to pjg do
        if e_key[j]=isi_key then
          e_key[j]:=#32;
  end;
  for i:=1 to pjg do
  begin
    isi_key:=e_key[i];
    if not (isi_key=#32) then
    Hasil:=Concat(hasil,isi_key);
  end;
  Result:=Hasil;
end;
//------------------------------------

//--------Generate Susunan Huruf-----------
function GenerateHuruf(Ekstrak : string):string;
var i : integer;
found : boolean;
isi_key : char;
begin
  pjg_key:=length(Ekstrak);
  for isi_key:='A' to 'Z' do
  begin
    found:=false;
    i:=0;
    while not found and (i<pjg_key) do
    begin
      i:=i+1;
      if Ekstrak[i]=isi_key then found:=true;
    end;
    if not found then
      Ekstrak:=Concat(Ekstrak,isi_key);
    end;
    Result:=Ekstrak;
end;
  //------------------------------------------

//-----generate tabel Kunci (Baris)-------------------
procedure TabelKunciBaris(List : string;var huruf_hilang:string);
var a,i,j : integer;
begin
  a:=1;
  for i := 0 to 4 do
    for j := 0 to 4 do
    begin
      if List[a] <> huruf_hilang then
        Form1.Grid.Cells[j,i]:=List[a]
      else
      begin
        Form1.Grid.Cells[j,i]:=List[a+1];
        a:=a+1;
      end;
      a:=a+1;
    end;
end;
//----------------------------------------

//-----generate tabel Kunci (Kolom)-------------------
procedure TabelKunciKolom(List : string;var huruf_hilang:string);
var a,i,j : integer;
begin
  a:=1;
  for i := 0 to 4 do
    for j := 0 to 4 do
    begin
      if List[a] <> huruf_hilang then
        Form1.Grid.Cells[i,j]:=List[a]
      else
      begin
        Form1.Grid.Cells[i,j]:=List[a+1];
        a:=a+1;
      end;
      a:=a+1;
    end;
end;
//----------------------------------------

//-----fungsi enkrip setiap 2 huruf---------------------
function Enkrip(Huruf1:string;var Huruf2:string):string;
var i,j : integer;
begin
with Form1.Grid do
begin
  for i := 0 to 4 do
    for j := 0 to 4 do
    begin
      if (Cells[i,j]) = (Huruf1) then
      begin
        kol1:=i;
        bar1:=j;
      end;
      if (Cells[i,j]) = (Huruf2) then
      begin
        kol2:=i;
        bar2:=j;
      end;
    end;

    if (kol1 <> kol2) or (bar1 <> bar2) then
      Enkrip:=concat(Cells[kol2,bar1],Cells[kol1,bar2]);

    if (kol1 = kol2) then
    begin
      bar1:=bar1+geser;
      bar2:=bar2+geser;
      if(bar1 > 4) then
        bar1:=bar1-5;
      if(bar2 > 4) then
        bar2:=bar2-5;

      Enkrip:=concat(Cells[kol2,bar1],Cells[kol1,bar2]);
    end;

    if (bar1 = bar2) then
    begin
      kol1:=kol1+geser;
      kol2:=kol2+geser;
      if(kol1 > 4) then
        kol1:=kol1-5;
      if(kol2 > 4) then
        kol2:=kol2-5;

      Enkrip:=concat(Cells[kol1,bar2],Cells[kol2,bar1]);
    end;
  end;
end;
//-----------------------------------------------------------

//-----Enkrip Kata-------------------------------------------
function Enkripsi(plainteks:string;var pjg : integer;var dummy:string):string;
var a,k : integer;
Hasil : string;
cipher : array[1..100] of string;
begin
  a:=0;
  k:=1;
  while k <= pjg do
  begin
    if(plainteks[k] <> plainteks[k+1]) then
    begin
      a:=a+1;
      X1:=plainteks[k];
      X2:=plainteks[k+1];
      if(plainteks[k+1] = '') then
        X2:=dummy;
      cipher[a]:=Enkrip(X1,X2);
    end;
    if(plainteks[k] = plainteks[k+1]) then
    begin
      a:=a+1;
      X1:=plainteks[k];
      X2:=dummy;
      cipher[a]:=Enkrip(X1,X2);
      k:=k-1;
    end;
    k:=k+2;
    Hasil:=concat(Hasil,cipher[a]);
  end;
  Result:=Hasil;
end;
//---------------------------------------------

//-----fungsi dekrip setiap 2 huruf---------------------
function Dekrip(Huruf1:string;var Huruf2:string):string;
var i,j : integer;
begin
with Form1.Grid do
begin
  for i := 0 to 4 do
    for j := 0 to 4 do
    begin
      if (Cells[i,j]) = (Huruf1) then
      begin
        kol1:=i;
        bar1:=j;
      end;
      if (Cells[i,j]) = (Huruf2) then
      begin
        kol2:=i;
        bar2:=j;
      end;
    end;

    if (kol1 <> kol2) or (bar1 <> bar2) then
      Dekrip:=concat(Cells[kol2,bar1],Cells[kol1,bar2]);

    if (kol1 = kol2) then
    begin
      bar1:=bar1-geser;
      bar2:=bar2-geser;
      if(bar1 < 0) then
        bar1:=bar1+5;
      if(bar2 < 0) then
        bar2:=bar2+5;

      Dekrip:=concat(Cells[kol2,bar1],Cells[kol1,bar2]);
    end;

    if (bar1 = bar2) then
    begin
      kol1:=kol1-geser;
      kol2:=kol2-geser;
      if(kol1 < 0) then
        kol1:=kol1+5;
      if(kol2 < 0) then
        kol2:=kol2+5;

      Dekrip:=concat(Cells[kol1,bar2],Cells[kol2,bar1]);
    end;
  end;
end;
//-----------------------------------------------------------

//-----Dekripsi Kata-------------------------------------------
function Dekripsi(cipherteks:string;var pjg : integer;var dummy:string):string;
var a,k : integer;
Hasil,Eks_Hasil : string;
plain : array[1..100] of string;
begin
  a:=0;
  k:=1;
  while k <= pjg do
  begin
    a:=a+1;
    X1:=cipherteks[k];
    X2:=cipherteks[k+1];

    plain[a]:=Dekrip(X1,X2);

    k:=k+2;
    Hasil:=concat(Hasil,plain[a]);
  end;

  pjg:=length(Hasil);
  for k:= 1 to pjg do
  begin
    if Hasil[k] <> dummy then
       Eks_Hasil:=concat(Eks_Hasil,Hasil[k]);
  end;
  Result:=Eks_Hasil;
end;
//---------------------------------------------

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  About.AboutBox.Show;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  c:=cb_hlg.Text;
  geser:=strtoint(cb_geser.Text);
  dum_c:=cb_dummy.Text;


  PlainT:=upper(edit1.Text);
  pjg_plain:=length(PlainT);
  Key:=upper(edit2.Text);
  pjg_key:=length(Key);

  Ekstrak:=EkstrakKunci(Key,pjg_key);

  List_Huruf:=GenerateHuruf(Ekstrak);

  if cb_tabel.Text = 'Kolom' then
    TabelKunciKolom(List_Huruf,c);
  if cb_tabel.Text = 'Baris' then
    TabelKunciBaris(List_Huruf,c);

  HasilEnkrip:=Enkripsi(PlainT,pjg_plain,dum_c);

  Edit3.Clear;
  Edit3.Font.Color:=clblue;
  Edit3.Text:=HasilEnkrip;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  CipherT:=edit4.Text;
  Pjg_cip:=length(CipherT);
  Key:=upper(edit2.Text);
  pjg_key:=length(Key);

  c:=cb_hlg.Text;
  geser:=strtoint(cb_geser.Text);
  dum_c:=cb_dummy.Text;

  Ekstrak:=EkstrakKunci(Key,pjg_key);

  List_Huruf:=GenerateHuruf(Ekstrak);

  if cb_tabel.Text = 'Kolom' then
    TabelKunciKolom(List_Huruf,c);
  if cb_tabel.Text = 'Baris' then
    TabelKunciBaris(List_Huruf,c);

  HasilDekrip:=Dekripsi(CipherT,pjg_cip,dum_c);

  Edit3.Clear;
  Edit3.Font.Color:=clgreen;
  Edit3.Text:=HasilDekrip;
end;