MODULE Disk;

   IMPORT Cell, Hole, RealCell, Files, TextRider, Strings, Out;

   CONST Size = 16;

   TYPE P* = POINTER TO T;
        T* = RECORD
           cells : ARRAY Size OF Cell.P;
           rotCount : INTEGER;
           next : P;
        END; (* T *)

   PROCEDURE ( d : P ) ReadCell* ( reader : TextRider.Reader ) : Cell.P;

   END ReadCell;
   
   PROCEDURE ( d : P ) WriteCellNum* ( index : INTEGER );
   
   BEGIN
      IF d.cells [ index ] IS Hole.P THEN
         d.next.WriteCellNum ( index );
      ELSE
         d.cells [ index ].WriteNum;
      END; (* IF *)
   END WriteCellNum;

   PROCEDURE ( d : P ) WriteAllCellNum*;
   
      VAR i : INTEGER;
   
   BEGIN
      FOR i := 0 TO Size - 1 DO
         d.WriteCellNum ( i );
      END; (* FOR *)
      Out.Ln;
   END WriteAllCellNum;
   
   PROCEDURE ( d : P ) GetText* ( index : INTEGER; VAR text : ARRAY OF CHAR );
   
   BEGIN
      IF d.cells [ index ] IS Hole.P THEN
         d.next.GetText ( index, text );
      ELSE
         d.cells [ index ].GetText ( text );
      END; (* IF *)
   END GetText;
   
   PROCEDURE ( d : P ) CheckText* ( good : ARRAY OF CHAR ) : BOOLEAN;
   
      VAR curText : ARRAY Size * RealCell.MaxLength OF CHAR;
          text : ARRAY RealCell.MaxLength OF CHAR;
          i : INTEGER;
          
   BEGIN
      Strings.Assign ( "", curText );
      FOR i := 0 TO Size - 1 DO
         d.GetText ( i, text );
         Strings.Append ( text, curText );
      END; (* FOR *)
      RETURN curText = good;
   END CheckText;

   PROCEDURE ( d : P ) GetColors* ( index : INTEGER;
                                    VAR colors : ARRAY OF CHAR );
   
   BEGIN
      IF d.cells [ index ] IS Hole.P THEN
         d.next.GetColors ( index, colors );
      ELSE
         d.cells [ index ].GetColors ( colors );
      END; (* IF *)
   END GetColors;
   
   PROCEDURE ( d : P ) CheckColors* () : BOOLEAN;
   
      VAR curColors : ARRAY Size * RealCell.MaxColors OF CHAR;
          colors : ARRAY RealCell.MaxColors OF CHAR;
          i, j : INTEGER;
          
   BEGIN
      Strings.Assign ( "", curColors );
      FOR i := 0 TO Size - 1 DO
         d.GetColors ( i, colors );
         Strings.Append ( colors, curColors );
      END; (* FOR *)
      FOR i := 0 TO Strings.Length ( curColors ) - 1 DO
         FOR j := i + 1 TO Strings.Length ( curColors ) - 1 DO
            IF curColors [ i ] = curColors [ j ] THEN
               RETURN FALSE;
            END; (* IF *)
         END; (* FOR *)
      END; (* FOR *)
      RETURN TRUE;
   END CheckColors;
   
   PROCEDURE ( d : P ) Rotate* () : BOOLEAN;

      VAR c : Cell.P;
          i : INTEGER;
   
   BEGIN
      c := d.cells [ 0 ];
      FOR i := 1 TO Size - 1 DO
         d.cells [ i - 1 ] := d.cells [ i ];
      END; (* FOR *)
      d.cells [ Size - 1 ] := c;
      INC ( d.rotCount );
      IF d.rotCount = Size THEN
         d.rotCount := 0;
         IF d.next # NIL THEN
            RETURN d.next.Rotate ();
         ELSE
            RETURN FALSE;
         END; (* IF *)
      ELSE
         RETURN TRUE;
      END; (* IF *)
   END Rotate;

   PROCEDURE Init* ( d : P; next : P; fileName : ARRAY OF CHAR );
   
      VAR f : Files.File;
          error : INTEGER;
          r : TextRider.Reader;
          line : ARRAY 256 OF CHAR;
          cell : Cell.P;
          n : INTEGER;
      
   BEGIN
      d.next := next;
      d.rotCount := 0;
      f := Files.Old ( fileName, { 0 }, error );
      NEW ( r ); TextRider.InitReader ( r, f );
      n := 0;
      REPEAT
         cell := d.ReadCell ( r );
         IF cell # NIL THEN
            d.cells [ n ] := cell;
            INC ( n );
         END; (* IF *)
      UNTIL cell = NIL;
      f.Close;
   END Init;

END Disk.