(* Cube - Utility to help solve the rubix cube *)

(*
 *    Top
 *     +---+
 *    /   /|
 *   +---+ +  Right
 *   |   |/ 
 *   +---+
 *     Front
 *)

open Printf

type color =
  | Red
  | Green
  | Yellow
  | Orange
  | Blue
  | White

let color_to_string = function
  | Red    -> "R"
  | Green  -> "G"
  | Yellow -> "Y"
  | Orange -> "O"
  | Blue   -> "B"
  | White  -> "W"

type square = color array array

type side = {
  mutable s: square;
  north: int;
  east:  int;
  south: int;
  west:  int;
}

let solved_square n color =
  Array.make n (Array.make n color)

let print_three_squares s1 s2 s3 =
  for i = 0 to Array.length s1 - 1 do
    for j = 0 to Array.length s1.(i) - 1 do
      printf "%s" (color_to_string s1.(i).(j))
    done;
    printf " ";
    for j = 0 to Array.length s1.(i) - 1 do
      printf "%s" (color_to_string s2.(i).(j))
    done;
    printf " ";
    for j = 0 to Array.length s1.(i) - 1 do
      printf "%s" (color_to_string s3.(i).(j))
    done;
    printf "\n"
  done

let print_square s =
  for i = 0 to Array.length s - 1 do
    for j = 0 to Array.length s.(i) - 1 do
      printf "%s" (color_to_string s.(i).(j))
    done;
    printf "\n"
  done

let print_square_indent indent s =
  for i = 0 to Array.length s - 1 do
    printf "%s" indent;
    for j = 0 to Array.length s.(i) - 1 do
      printf "%s" (color_to_string s.(i).(j))
    done;
    printf "\n"
  done

type cube = side array

let solved_cube n =
  let red_side    = { s = solved_square n Red;    north= 3; east= 5; south= 1; west= 4} in
  let green_side  = { s = solved_square n Green;  north= 0; east= 5; south= 2; west= 4} in
  let orange_side = { s = solved_square n Orange; north= 1; east= 5; south= 3; west= 4} in
  let blue_side   = { s = solved_square n Blue;   north= 2; east= 5; south= 0; west= 4} in
  let white_side  = { s = solved_square n White;  north= 3; east= 0; south= 1; west= 2} in
  let yellow_side = { s = solved_square n Yellow; north= 3; east= 2; south= 1; west= 0} in
  [| red_side; green_side; orange_side; blue_side; white_side; yellow_side |]
  (*   0          1         2              3          4         5  *)

let turn_side c num =
  let face = c.(num).s in
  let new_face = [|
    [| face.(2).(0) ; face.(1).(0) ; face.(0).(0) |];
    [| face.(2).(1) ; face.(1).(1) ; face.(0).(1) |];
    [| face.(2).(2) ; face.(1).(2) ; face.(0).(2) |];
  |] in
  let n = c.(c.(num).north).s in
  let e = c.(c.(num).east).s in
  let s = c.(c.(num).south).s in
  let w = c.(c.(num).west).s in
  if num < 4 then begin
  let new_n = [|
    [| n.(0).(0) ; n.(0).(1) ; n.(0).(2) |];
    [| n.(1).(0) ; n.(1).(1) ; n.(1).(2) |];
    [| w.(2).(2) ; w.(1).(2) ; w.(0).(2) |];
  |] in
  let new_e = [|
    [| n.(2).(0) ; e.(0).(1) ; e.(0).(2) |];
    [| n.(2).(1) ; e.(1).(1) ; e.(1).(2) |];
    [| n.(2).(2) ; e.(2).(1) ; e.(2).(2) |];
  |] in
  let new_s = [|
    [| e.(2).(0) ; e.(1).(0) ; e.(0).(0) |];
    [| s.(1).(0) ; s.(1).(1) ; s.(1).(2) |];
    [| s.(2).(0) ; s.(2).(1) ; s.(2).(2) |];
  |] in
  let new_w = [|
    [| s.(0).(0) ; s.(0).(1) ; s.(0).(2) |];
    [| w.(1).(0) ; w.(1).(1) ; w.(1).(2) |];
    [| w.(2).(0) ; w.(2).(1) ; w.(2).(2) |];
  |] in
  c.(num).s <- new_face;
  c.(c.(num).north).s <- new_n;
  c.(c.(num).east).s <- new_e;
  c.(c.(num).south).s <- new_s;
  c.(c.(num).west).s <- new_w;
  c
  end else if num = 4 then begin
  let new_n = [|
    [| w.(0).(0) ; n.(0).(1) ; n.(0).(2) |];
    [| w.(1).(0) ; n.(1).(1) ; n.(1).(2) |];
    [| w.(2).(0) ; n.(2).(1) ; n.(2).(2) |];
  |] in
  let new_e = [|
    [| n.(0).(0) ; e.(0).(1) ; e.(0).(2) |];
    [| n.(1).(0) ; e.(1).(1) ; e.(1).(2) |];
    [| n.(2).(0) ; e.(2).(1) ; e.(2).(2) |];
  |] in
  let new_s = [|
    [| e.(0).(0) ; s.(0).(1) ; s.(0).(2) |];
    [| e.(1).(0) ; s.(1).(1) ; s.(1).(2) |];
    [| e.(2).(0) ; s.(2).(1) ; s.(2).(2) |];
  |] in
  let new_w = [|
    [| s.(0).(0) ; w.(0).(1) ; w.(0).(2) |];
    [| s.(1).(0) ; w.(1).(1) ; w.(1).(2) |];
    [| s.(2).(0) ; w.(2).(1) ; w.(2).(2) |];
  |] in
  c.(num).s <- new_face;
  c.(c.(num).north).s <- new_n;
  c.(c.(num).east).s <- new_e;
  c.(c.(num).south).s <- new_s;
  c.(c.(num).west).s <- new_w;
  c
  end else begin
  let new_n = [|
    [| n.(0).(0) ; n.(0).(1) ; e.(0).(2) |];
    [| n.(1).(0) ; n.(1).(1) ; e.(1).(2) |];
    [| n.(2).(0) ; n.(2).(1) ; e.(2).(2) |];
  |] in
  let new_e = [|
    [| e.(0).(0) ; e.(0).(1) ; s.(0).(2) |];
    [| e.(1).(0) ; e.(1).(1) ; s.(1).(2) |];
    [| e.(2).(0) ; e.(2).(1) ; s.(2).(2) |];
  |] in
  let new_s = [|
    [| s.(0).(0) ; s.(0).(1) ; w.(0).(2) |];
    [| s.(1).(0) ; s.(1).(1) ; w.(1).(2) |];
    [| s.(2).(0) ; s.(2).(1) ; w.(2).(2) |];
  |] in
  let new_w = [|
    [| w.(0).(0) ; w.(0).(1) ; n.(0).(2) |];
    [| w.(1).(0) ; w.(1).(1) ; n.(1).(2) |];
    [| w.(2).(0) ; w.(2).(1) ; n.(2).(2) |];
  |] in
  c.(num).s <- new_face;
  c.(c.(num).north).s <- new_n;
  c.(c.(num).east).s <- new_e;
  c.(c.(num).south).s <- new_s;
  c.(c.(num).west).s <- new_w;
  c
  end

let print_cube c =
  for i = 0 to Array.length c - 1 do
    print_square c.(i).s;
    printf "\n"
  done

let nice_print_cube c =
  print_square_indent "    " c.(0).s;
  printf "\n";
  print_three_squares c.(4).s c.(1).s c.(5).s;
  printf "\n";
  print_square_indent "    " c.(2).s;
  printf "\n";
  print_square_indent "    " c.(3).s;
  printf "\n"

let _ =
    let cube = solved_cube 3 in
    let cube = ref cube in
    for i = 0 to 10 do
      let twists = [ 0 ] in
      cube := List.fold_left turn_side !cube twists;
      print_newline();
      print_newline();
      print_newline();
      print_newline();
      print_newline();
      print_newline();
      nice_print_cube !cube;
      print_newline();
      Unix.sleep 1
    done