unit ChessBoard;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, Grids,
  StdCtrls{, pawnswitch};

type

  { TFormChessBoard }

  TFormChessBoard = class(TForm)
    DGridChess: TDrawGrid;
    BtnResign: TButton;
    BtnDraw: TButton;
    BtnSave: TButton;
    BtnQuit: TButton;
    LblTurn: TLabel;
    LblGuidance: TLabel;
    procedure DGridChessBeforeSelection(Sender: TObject; aCol, aRow: integer);
    procedure DGridChessDrawCell(Sender: TObject; aCol, aRow: integer;
      aRect: TRect; aState: TGridDrawState);
    procedure BtnQuitClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);

  private
    { private declarations }
  public
    { public declarations }
  end;

type
  TPieces = record
    Name: string[6];
    Colour: string[6];
    Player: integer;
    PNG: TPortableNetworkGraphic;
    CanSelect: boolean;
    FirstPawnMove: boolean
  end;

  TFile = record
    Player1Colour: string[6];
    Player2Colour: string[6];
    Player1Name: string[15];
    Player2name: string[15];
    Boardsize: integer;
    CurrentTurn: integer;
    SavePiecesArray: array[0..15, 0..15] of TPieces;
  end;

var
  FormChessBoard: TFormChessBoard;
  Pieces: Tpieces;
  PiecesArray: array[0..15, 0..15] of TPieces;
  ONMOVE: boolean;
  CurrentTurn, CurrentCol, CurrentRow: integer;

implementation

{$R *.lfm}

{ TFormChessBoard }

//Get's the piece files and loads them into the grid
procedure PieceStorage(var DGridChess: TDrawGrid);
var
  Count, Count2: integer;
begin

  //Draws each piece onto the chess board
  for Count := 0 to 15 do
    for count2 := 0 to 15 do
    begin
      Pieces := PiecesArray[Count, count2];
      if pieces.Name <> '' then
      begin
        try
          DGridChess.canvas.Draw(64 * Count, 64 * count2, pieces.PNG);
        finally

        end;
      end;
    end;

end;


//Fills the cells of the chess board
procedure TFormChessBoard.DGridChessDrawCell(Sender: TObject;
  aCol, aRow: integer; aRect: TRect; aState: TGridDrawState);
var
  RowNumber, ColumnNumber, Count: integer;
begin

  //  Colours the cells of the grid black/white
  with TDrawGrid(Sender) do
  begin

    // Fills everything with white
    DGridChess.Color := clwhite;

    // Fills the correct cells with black
    for RowNumber := 0 to 7 do
    begin
      if rownumber mod 2 = 0 then
        ColumnNumber := 1
      else
        columnnumber := 0;
      for Count := 1 to 4 do
      begin
        Canvas.Brush.Color := clblack;
        DGridChess.Canvas.FillRect(TDrawGrid(Sender).CellRect(
          columnnumber, rownumber));
        ColumnNumber := columnnumber + 2;
      end;
    end;
  end;
  PieceStorage(DGridChess);
end;

function ToggleTurn(var CurrentTurn: integer): integer;
begin
  //Toggles who's turn it is
  if CurrentTurn = 1 then
  begin
    ToggleTurn := 2;
    FormChessboard.LblTurn.Caption := ('Player 2''s turn');
  end
  else
  begin
    ToggleTurn := 1;
    FormChessboard.LblTurn.Caption := ('Player 1''s turn');
  end;
end;

procedure VisuallyMove(ACol, Arow, CurrentCol, CurrentRow: integer);
begin
  //Loads the data of the piece into the new cell
  PiecesArray[ACol, ARow] := PiecesArray[CurrentCol, CurrentRow];
  with PiecesArray[acol, arow] do
  begin
    FirstPawnMove := False;
    PNG := TPortableNetworkGraphic.Create;
    PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
  end;
  //Clears the piece's previous cell
  with PiecesArray[CurrentCol, CurrentRow] do
  begin
    Player := 0;
    Colour := '';
    Name := '';
    PNG.Free;
    FirstPawnMove := False;
  end;
  OnMove := False;
end;

//Pawn Piece Logic
procedure PawnCheck(ACol, ARow: integer);
var
  PieceDirection, FirstMoveDirection, CurrentPlayer, EndofBoard, OtherPlayer: integer;
begin

  if PiecesArray[Acol, Arow].Player = 1 then
  begin
    PieceDirection := -1;
    FirstMoveDirection := -2;
    CurrentPlayer := 1;
    OtherPlayer := 2;
    EndofBoard := 0;
  end
  else
  begin
    PieceDirection := 1;
    FirstMoveDirection := 2;
    CurrentPlayer := 2;
    OtherPlayer := 1;
    EndofBoard := 7;
  end;

  if PiecesArray[Acol, Arow + PieceDirection].Player = 0 then
    PiecesArray[Acol, Arow + PieceDirection].CanSelect := True;

  if PiecesArray[Acol + 1, Arow + PieceDirection].Player = OtherPlayer then
    PiecesArray[Acol + 1, Arow + PieceDirection].CanSelect := True;

  if PiecesArray[Acol - 1, Arow + PieceDirection].Player = OtherPlayer then
    PiecesArray[Acol - 1, Arow + PieceDirection].CanSelect := True;

  if (PiecesArray[Acol, Arow].FirstPawnMove = True) and
    (PiecesArray[Acol, Arow + FirstMoveDirection].Player <> CurrentPlayer) then
    PiecesArray[Acol, Arow + FirstMoveDirection].CanSelect := True;

end;

//Knight Piece Logic
procedure KnightCheck(ACol, ARow: integer);
begin

end;
//Rook Piece Logic
procedure RookCheck(ACol, ARow: integer);
begin

end;
//King Piece Logic
procedure KingCheck(ACol, ARow: integer);
begin

end;
//Queen Piece Logic
procedure QueenCheck(ACol, ARow: integer);
begin

end;
//Bishop Piece Logic
procedure BishopCheck(ACol, ARow: integer);
begin

end;

//Checks where the selected piece can move to
procedure CheckingPiece(ACol, ARow: integer);
var
  Count, count2: integer;
begin
  //resets the cells where the piece can move to
  for Count := 1 to 15 do
    for count2 := 1 to 15 do
      PiecesArray[Count, count2].CanSelect := False;

  //Does the corresponding check on where the piece
  //can move to dependng on what the piece is
  if PiecesArray[ACol, ARow].Name = 'Pawn' then
    PawnCheck(ACol, ARow)
  else if PiecesArray[ACol, ARow].Name = 'Knight' then
    KnightCheck(ACol, ARow)
  else if PiecesArray[ACol, ARow].Name = 'Rook' then
    RookCheck(ACol, ARow)
  else if PiecesArray[ACol, ARow].Name = 'King' then
    KingCheck(ACol, ARow)
  else if PiecesArray[ACol, ARow].Name = 'Queen' then
    QueenCheck(ACol, ARow)
  else if PiecesArray[ACol, ARow].Name = 'Bishop' then
    BishopCheck(ACol, ARow);

end;

procedure TFormChessBoard.DGridChessBeforeSelection(Sender: TObject;
  aCol, aRow: integer);
begin

  //Checks if the player clicks no piece as the piece to move, do nothing
  if (PiecesArray[ACol, ARow].Name = '') and (OnMove = False) then
  begin
  end
  else
  //If selected piece matches who's turn it is, then check where the piece can move to
  if (PiecesArray[acol, arow].Player = CurrentTurn) then
  begin

    //Gets the cell coordinates of the piece which needs moving
    CurrentCol := Acol;
    CurrentRow := Arow;

    CheckingPiece(Acol, Arow);
    OnMove := True;
  end
  else
  if ((Acol = CurrentCol) and (Arow = CurrentRow)) then
    OnMove := False
  else

  //Checks if the player is able to move the piece there
  if PiecesArray[ACol, ARow].CanSelect = True then
  begin
    CurrentTurn := ToggleTurn(CurrentTurn);
    VisuallyMove(Acol, Arow, CurrentCol, CurrentRow);
    //Moves the piece to the new cell
  end;

end;




//Closes form when the quit button is selected
procedure TFormChessBoard.BtnQuitClick(Sender: TObject);
begin
  Close;
end;


//IN DEVELOPMENT-Hardcode piece initialisation (will be called from file later in development)
procedure TFormChessBoard.FormCreate(Sender: TObject);

var
  Count, Count2: integer;
begin

  with Pieces do
  begin
    //Initialisation of the variables
    OnMove := False;
    CurrentTurn := 1;
    CurrentCol := -1;
    CurrentRow := -1;
    LblTurn.Caption := ('Player 1''s turn');
    FirstPawnMove := False;
    Name := '';
    Colour := '';
    Player := 0;
    CanSelect := False;
    for Count := 1 to 15 do
      for Count2 := 1 to 15 do
      begin
        PiecesArray[Count, Count2] := Pieces;
      end;

    //TEMPORARY- Hard coded piece initialisation
    Player := 1;
    Colour := 'White';

    Name := 'Bishop';
    PiecesArray[2, 7] := Pieces;
    PiecesArray[2, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[2, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
    PiecesArray[5, 7] := Pieces;
    PiecesArray[5, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[5, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Rook';
    PiecesArray[0, 7] := Pieces;
    PiecesArray[0, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[0, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
    PiecesArray[7, 7] := Pieces;
    PiecesArray[7, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[7, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Knight';
    PiecesArray[6, 7] := Pieces;
    PiecesArray[6, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[6, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
    PiecesArray[1, 7] := Pieces;
    PiecesArray[1, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[1, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Queen';
    PiecesArray[3, 7] := Pieces;
    PiecesArray[3, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[3, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'King';
    PiecesArray[4, 7] := Pieces;
    PiecesArray[4, 7].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[4, 7].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Pawn';
    FirstPawnMove := True;
    for Count := 0 to 7 do
    begin
      PiecesArray[Count, 6] := Pieces;
      PiecesArray[Count, 6].PNG := TPortableNetworkGraphic.Create;
      PiecesArray[Count, 6].PNG.LoadFromFile('Pieces\' + Colour +
        '\' + Name + '.png');
    end;

    Player := 2;
    Colour := 'Black';
    FirstPawnMove := False;

    Name := 'Bishop';
    PiecesArray[2, 0] := Pieces;
    PiecesArray[2, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[2, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
    PiecesArray[5, 0] := Pieces;
    PiecesArray[5, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[5, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Rook';
    PiecesArray[0, 0] := Pieces;
    PiecesArray[0, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[0, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
    PiecesArray[7, 0] := Pieces;
    PiecesArray[7, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[7, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Knight';
    PiecesArray[1, 0] := Pieces;
    PiecesArray[1, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[1, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');
    PiecesArray[6, 0] := Pieces;
    PiecesArray[6, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[6, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Queen';
    PiecesArray[3, 0] := Pieces;
    PiecesArray[3, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[3, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'King';
    PiecesArray[4, 0] := Pieces;
    PiecesArray[4, 0].PNG := TPortableNetworkGraphic.Create;
    PiecesArray[4, 0].PNG.LoadFromFile('Pieces\' + Colour + '\' + Name + '.png');

    Name := 'Pawn';
    FirstPawnMove := True;
    for Count := 0 to 7 do
    begin
      PiecesArray[Count, 1] := Pieces;
      PiecesArray[Count, 1].PNG := TPortableNetworkGraphic.Create;
      PiecesArray[Count, 1].PNG.LoadFromFile('Pieces\' + Colour +
        '\' + Name + '.png');
    end;
  end;
end;

end.