(***********************************************************************)
(*                                                                     *)
(*                               TAToo                                 *)
(*                                                                     *)
(*                     Kim Nguyen, LRI UMR8623                         *)
(*                   Université Paris-Sud & CNRS                       *)
(*                                                                     *)
(*  Copyright 2010-2012 Université Paris-Sud and Centre National de la *)
(*  Recherche Scientifique. All rights reserved.  This file is         *)
(*  distributed under the terms of the GNU Lesser General Public       *)
(*  License, with the special exception on linking described in file   *)
(*  ../LICENSE.                                                        *)
(*                                                                     *)
(***********************************************************************)

open Format

exception InvalidUtf8Codepoint of int

let subscripts = "₀₁₂₃₄₅₆₇₈₉"
let superscripts = "⁰¹²³⁴⁵⁶⁷⁸⁹"

let char_length c =
  let code = Char.code c in
    if code <= 0x7f then 1
    else if 0xc2 <= code && code <= 0xdf then 2
    else if 0xe0 <= code && code <= 0xef then 3
    else if 0xf0 <= code && code <= 0xf4 then 4
    else raise (InvalidUtf8Codepoint code)


let next_char s i len =
  let n = i + char_length s.[i] in
    if n >= len then -1 else n

let str_len s =
  let len = String.length s in
  let rec loop i acc =
    if i == -1 then acc
    else loop (next_char s i len) (acc+1)
  in
    loop 0 0

let length = str_len

let get_char s i =
  let len = String.length s in
  let rec loop j count =
    if count == i then String.sub s j (char_length s.[j])
    else loop (next_char s j len) (count+1)
  in
    loop 0 0


let format_number digits i =
  let s = string_of_int i in
  let len = String.length s in
  let buf = Buffer.create (len*4) in
    for i = 0 to len - 1 do
      let d = Char.code s.[i] - Char.code '0' in
	Buffer.add_string buf (get_char digits d)
    done;
    Buffer.contents buf

let rev_explode s =
  let len = str_len s in
  let rec loop i acc =
      if i >= len then acc
      else
	loop (i+1) ((get_char s i) :: acc)
  in
      loop 0 []


let explode s = List.rev (rev_explode s)

let combine_all comp s =
  let l = rev_explode s in
  String.concat "" (List.fold_left (fun acc e -> comp::e::acc) [] l)


let subscript = format_number subscripts
let superscript = format_number superscripts
let down_arrow = "↓"
let up_arrow = "↑"
let right_arrow = "→"
let left_arrow =  "←"
let epsilon = "ϵ"
let bullet = "•"
let big_sigma = "∑"
let cap = "∩"
let cup = "∪"
let lnot = "¬"
let wedge = "∧"
let vee = "∨"
let top = "⊤"
let bottom = "⊥"
let dummy = "☠"
let inverse = "⁻¹"
let double_right_arrow = "⇒"
let combining_overbar = "\204\133"
let combining_underbar = "\204\178"
let combining_stroke = "\204\182"
let combining_vertical_line = "\226\131\146"


let overline s = combine_all combining_overbar s
let underline s = combine_all combining_underbar s
let strike s = combine_all combining_stroke s

let padding i = String.make i ' '
let line i = String.make i '_'




let ppf f fmt s =
  pp_print_string fmt (f s)

let pp_overline = ppf overline
let pp_underline = ppf underline
let pp_strike = ppf strike
let pp_subscript = ppf subscript
let pp_superscript = ppf superscript
let dummy_printer _ () = ()

let pp_print_list ?(sep=dummy_printer) printer fmt l =
  match l with
    [] -> ()
  | [ e ] -> printer fmt e
  | e :: es -> printer fmt e; List.iter
    (fun x ->
      sep fmt ();
      fprintf fmt "%a" printer x) es

let pp_print_array ?(sep=dummy_printer) printer fmt a =
  pp_print_list ~sep:sep printer fmt (Array.to_list a)

let print_list ?(sep=" ") printer fmt l =
  let sep_printer fmt () =
    pp_print_string fmt sep
  in
  pp_print_list ~sep:sep_printer printer fmt l

let print_array ?(sep=" ") printer fmt a =
  print_list ~sep:sep printer fmt (Array.to_list a)