with

    Things;

private with

    FLTK.Images.RGB.PNG,
    Misc;


package Squares is


    type Square is tagged private;

    Void : constant Square;

    Wall  : constant Square;
    Space : constant Square;
    Empty : constant Square;
    Goal  : constant Square;

    function "="
           (A, B : in Square)
        return Boolean;




    function Is_Walkable
           (This : in Square)
        return Boolean;




    function Get_Contents
           (This : in Square)
        return Things.Thing
        with Pre => Is_Walkable (This);

    procedure Set_Contents
           (This : in out Square;
            Item : in     Things.Thing)
        with Pre => Is_Walkable (This);




    procedure Draw
           (This : in Square;
            X, Y : in Integer);


private


    type Square is tagged record
        Walkable   : Boolean;
        Contents   : Things.Thing;
        Self_Image : access FLTK.Images.RGB.PNG.PNG_Image;
    end record;


    Image_Dir : String := Misc.Origin & "/../share/sokoban/img";


    Wall_Image : aliased FLTK.Images.RGB.PNG.PNG_Image :=
        FLTK.Images.RGB.PNG.Forge.Create (Image_Dir & "/wall.png");
    Space_Image : aliased FLTK.Images.RGB.PNG.PNG_Image :=
        FLTK.Images.RGB.PNG.Forge.Create (Image_Dir & "/space.png");
    Empty_Image : aliased FLTK.Images.RGB.PNG.PNG_Image :=
        FLTK.Images.RGB.PNG.Forge.Create (Image_Dir & "/empty.png");
    Goal_Image : aliased FLTK.Images.RGB.PNG.PNG_Image :=
        FLTK.Images.RGB.PNG.Forge.Create (Image_Dir & "/goal.png");


    Void : constant Square :=
        (Walkable => False, Contents => Things.Nothing, Self_Image => null);


    Wall : constant Square :=
        (Walkable => False, Contents => Things.Nothing, Self_Image => Wall_Image'Access);
    Space : constant Square :=
        (Walkable => False, Contents => Things.Nothing, Self_Image => Space_Image'Access);
    Empty : constant Square :=
        (Walkable => True, Contents => Things.Nothing, Self_Image => Empty_Image'Access);
    Goal : constant Square :=
        (Walkable => True, Contents => Things.Nothing, Self_Image => Goal_Image'Access);


end Squares;