(*
 *  Copyright (c) 2005, 2006, 2007 Abram Hindle
 *  
 *  This file is part of CaptchaBreaker

 *  CaptchaBreaker is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.

 *  Foobar is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.

 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *)
(* Machine Learning Shit, Extractors etc. *)
open Shape;;
open Images;;
open OImages;;
open Fft;; 
open Abez;;

(* Features we want to add, 
   * count pts 
   * centroid
   * x mid point
   * y mid point
   * aspect
   * sum columns
   * FFT
   * End points
   * loops
*)

let fft = new jfft;;

let b_w_h h =
  let height = h#height in
  let width = h#width in
    (width,height) 
;;
let hget bmp x y =
  let c = bmp#get x y in
  1.0 -. (float_of_int (c.r  )) /. 255.
;;

let cnt_pts b =
  let (w,h) = b_w_h b in
  let o = ref 0. in
  for y = 0 to (h - 1) do
    for x = 0 to (w - 1) do
      o := !o +. (hget b x y)
    done;
  done;
  ((!o),(float_of_int (w*h)))
;;

(* centroid, and normalized centroid *)
let centroid b =
  let (w,h) = b_w_h b in
  let xo = ref 0. in
  let yo = ref 0. in
  let fi = float_of_int in
  for y = 0 to (h - 1) do
    for x = 0 to (w - 1) do
      let g = hget b x y in
      yo := !yo +. (fi y) *. g ;
      xo := !xo +. (fi x) *. g ;
    done;
  done;
  let fh1 = fi (h - 1) in
  let fw1 = fi (w - 1) in
  yo := !yo /. (fh1) -. fh1 /. 2.0;
  xo := !xo /. (fw1) -. fw1 /. 2.0;
  (!xo , !yo, (!xo /. (fw1 /. 2.0)), (!yo /. (fh1 /. 2.0)))
;;



	
let normalized_cnt_pts b =
  let (points,total_points) = cnt_pts b in
  points /. total_points
;;

let get_aspect (_,_,x,y) b =
  let (w,h) = b_w_h b in
  let fw = (float_of_int ( w - 1)) in
  let fh = (float_of_int ( h - 1)) in
  (y *. fh +. fh /. 2.0)  /. ( x *. fw  +. fw /. 2.0)
;;

let resample_to w h bmp =
  let (hw,hh) = b_w_h bmp in
  let arr = Array.create (w * h) 0. in
  let arrget i = 
    arr.(i)
  in
  let arradd i x =
    arr.(i) <- arr.(i) +. x;
  in
  let index x y w = y * w + x in

  for y = 0 to (hh - 1) do

    for x = 0 to (hw - 1) do
      let y' = y * (h - 1) / (hh - 1) in
      let x' = x * (w - 1) / (hw - 1)in
      let dx = hget bmp x y in
      arradd (index x' y' w) dx;
    done;
   done;
  arr
;;
  
let normalized_subset w h bmp =
  let index x y w = y * w + x in
  let arr = resample_to w h bmp in
  let arrdiv i x =
    arr.(i) <- arr.(i) /. x;
  in
  let arrget x y=
    arr.(index x y w)
  in
  for y = 0 to (h - 1) do
    let total = ref 0. in
    for x = 0 to (w - 1) do
      total := !total +. (arrget x y)
    done;
    if ((!total *. !total) > 0.0000000001) then
      for x = 0 to (w - 1) do
        arrdiv (index x y w) !total;
      done; 
  done;
  Array.to_list arr
;;

let resample_to_aspect w h bmp =
  let (hw,hh) = b_w_h bmp in
  let fi = float_of_int in
  let l = w * h in
  let arr = Array.create l (0.,0) in
  let outarr = Array.create l 0. in
  let index x y  = x + w * y in
  let aspect = (fi hh) /. (fi hw) in
  let outset  x y v =
    outarr.(index x y) <- v 
  in
  let arrget x y =
    arr.(index x y)
  in
  let arradd x y dx =
    let i = index x y in
    if (i < l) then
      let (v,c) = arr.(i) in
      arr.(i) <- (v+.dx,c+1)
  in
  let xw = int_of_float ((fi (w)) /. aspect) in
  let yh = int_of_float ((fi (h)) *. aspect) in
  let f h' w' =
    let yoff = (h - h')/2 in
    let xoff = (w - w')/2 in
    let h = h' in
    let w = w' in
(*     print_endline ((string_of_int h) ^ " " ^(string_of_int w)); *)
    for y = 0 to (hh - 1) do
      for x = 0 to (hw - 1) do
	let y' = yoff + y * (h - 1) / (hh - 1) in
	let x' = xoff + x * (w - 1) / (hw - 1)in
	let dx = hget bmp x y in
	arradd x' y' dx;
      done
    done
  in
  let _ = if (aspect = 1.0) then
    f h w
  else if (aspect < 1.0) then
    f yh w
  else 
    f h xw
  in
    (* now normalize again *)
  for y = 0 to (h - 1) do
    for x = 0 to (w - 1) do
      let (v,c) = arrget x y in
      if (c > 0) then
	outset x y (v /. (float_of_int c))
    done;
  done;
    Array.to_list outarr
;;  
  

let get_columns n l =
  let arr = Array.create n 0. in
  Abez.iteri (fun i x ->
		arr.(i mod n) <- arr.(i mod n) +. x
	     ) l;
  Array.to_list arr
;;

let buffer_to_linear bmp =
  let (w,h) = b_w_h bmp in
  let arr = Array.create (w * h) 0. in
  for y = 0 to (h-1) do
    for x = 0 to (w-1) do
      arr.(x + y * w) <- hget bmp x y
    done
  done;
    arr
;;

let run_fft_on lin_arr n st en =
    let imag = Array.create n 0. in
    let real = Array.create n 0. in
    let imago = Array.create n 0. in
    let realo = Array.create n 0. in
      for i = st to en do
	real.(i - st) <- lin_arr.(i);
      done;
      fft#fft_f real imag realo imago;
      (realo,imago)
;;



let get_fft min' max'  w h samples =  
  let lin_arr = Array.of_list samples in
  let run_fft_on = run_fft_on lin_arr in
  let arrl = h * w in
  let rec find_next_two n s =
    if (s >= n) then s else (find_next_two n (s*2))
  in
  let max2 = find_next_two (min arrl max') 1 in
  let rec powers_of_two = function
      n when n >= min' -> n :: (powers_of_two (n/2))
    |	_ -> []	
  in			
  let pwrs = powers_of_two max2 in 
  let lists = List.flatten ( 
    List.map ( 
      fun m ->
	let max = arrl / m in
	  List.flatten (
	    Abez.for_map (
	      fun i ->
		let start = m * i in
		let ending = start + m - 1 in
		let ending = min (arrl-1) ending in
		let (r,i) = run_fft_on m start ending in
		  Array.to_list r
	    ) max
	  )
    ) pwrs ) in
    lists
;;

let get_avg_fft max2 h w samples =  
  let lin_arr = Array.of_list samples in
  let run_fft_on = run_fft_on lin_arr in
  let arrl = h * w in
  let avg = Array.create max2 0. in
  let max = arrl / max2 in
    Abez.fori (
      fun i ->
	let start = max2 * i in
	let ending = start + max2 - 1 in
	let ending = min (arrl-1) ending in
	let (r,i) = run_fft_on max2 start ending in
	Abez.add_array avg r;
    ) max;
      Array.to_list avg

;;