(*
  The function to_braille from this unit translates a string from UTF8 chars to Braille chars.
  The dictionaries were taken from http://www.ibc.gov.br/?catid=110&blogid=1&itemid=479
  and from http://www.braillevirtual.fe.usp.br/pt/Portugues/braille.html

  Copyright 2011
*)

unit mod_braille;

interface

{$mode objfpc}{$H+}

uses
  browsermodules, lclproc;

type

  { TBrailleBrowserModule }

  TBrailleBrowserModule = class(TBrowserModule)
  public
    constructor Create; override;
    function HandleOnPageLoad(AInput: string; out AOutput: string): Boolean; override;
  end;

function ConvertUTF8TextToBraille(Line: string): string;
function ConvertUTF8HtmlTextToBraille(AInput: string): string;

implementation

type
  dictionary = array[1..32] of string;
  dictionary_pointer = ^dictionary;

const

  number_signal = chr($e2) + chr($a0) + chr($bc);
  caps_signal = chr($e2) + chr($a0) + chr($a8);

  d1: dictionary = ({!} chr($96), {"} chr($a6), {#} 'TODO', {(*$*)} chr($b0),
    {%} chr($b8) + chr($e2) + chr($a0) + chr($b4), {&} chr($af), {'} chr($84),
    {(} chr($a3) + chr($e2) + chr($a0) + chr($84), {)} chr($a0) + chr($e2) + chr($a0) + chr($9c),
    {*} chr($94), {+} chr($96), {,} chr($82), {-} chr($a4), {.} chr($84),
    {/} chr($90) + chr($e2) + chr($a0) + chr($b2), {0} chr($9a), {1} chr($81),
    {2} chr($83), {3} chr($89), {4} chr($99), {5} chr($91), {6} chr($8b),
    {7} chr($9b), {8} chr($93), {9} chr($8a), {:} chr($92), {;} chr($86),
    {<} chr($aa), {=} chr($b6), {>} chr($95), {?} chr($a2), {@} 'TODO');

  d2: dictionary = ({a} chr($81), {b} chr($83), {c} chr($89), {d} chr($99),
    {e} chr($91), {f} chr($8b), {g} chr($9b), {h} chr($93), {i} chr($8a),
    {j} chr($9a), {k} chr($85), {l} chr($87), {m} chr($8d), {n} chr($9d),
    {o} chr($95), {p} chr($8f), {q} chr($9f), {r} chr($97), {s} chr($8e),
    {t} chr($9e), {u} chr($a5), {v} chr($a7), {w} chr($ba), {x} chr($ad),
    {y} chr($bd), {z} chr($b5), '', '', '', '', '', '');

  d3: dictionary = ({a + grave} chr($ab), {a + acute} chr($b7),
    {a + circumflex} chr($a1), {a + tilde} chr($9c), {a + diaeresis} 'TODO',
    {a + ring above} 'TODO', {ae} 'TODO', {c + cedilla} chr($af),
    {e + grave} chr($ae), {e + acute} chr($bf), {e + circumflex} chr($a3),
    {e + diaeresis} 'TODO', {i + grave} chr($a9), {i + acute}  chr($8c),
    {i + circumflex} 'TODO', {i + diaeresis} chr($bb), {eth} 'TODO',
    {n + tilde} 'TODO', {o + grave} chr($ba), {o + acute} chr($ac),
    {o + circumflex} chr($b9), {o + tilde} chr($aa), {o + diaeresis} 'TODO',
    {division sign} 'TODO', {o + stroke} 'TODO', {u + grave} chr($b1),
    {u + acute} chr($be), {u + circumflex} 'TODO', {u + diaeresis} chr($b3),
    {y + acute} 'TODO', {thorn} 'TODO', {y + diaeresis} 'TODO');

function ConvertUTF8CharacterToBraille(AInput: string): string;
begin
end;

function ConvertUTF8TextToBrailleNew(AInput: string): string;
var
  lInput: PChar;
  lPos: Integer;
  lCharSize: Integer;
  lCurChar: string;
begin
  Result := '';
  lInput := PChar(AInput);
  lPos := 0;
  while lPos < Length(AInput) do
  begin
    lCharSize := LCLProc.UTF8CharacterLength(lInput);

    SetLength(lCurChar, lCharSize);
    Move(lCurChar[1], lInput^, lCharSize);
    Result := Result + ConvertUTF8CharacterToBraille(lCurChar);

    Inc(lInput, lCharSize);
    Inc(lPos, lCharSize);
  end;
end;

function ConvertUTF8TextToBraille(Line: string): string;
var
  Count, count_aux, n, n_aux, decr: integer;
  Braille_string, string_aux: string;
  num, accented: boolean;
  dict_p: dictionary_pointer;
begin
  Braille_string := '';
  num := False;
  accented := False;
  New(dict_p);
  decr := 0;
  Count := 1;
  n_aux := 0;
  if Line = '' then Result := '';

  while Count <= length(Line) do

  begin
    if Line[Count] = ' ' then      {reproduce the empty space and go to next iteration}
    begin
      Braille_string := Braille_string + chr($e2) + chr($a0) + chr($80);
      Count := Count + 1;
      continue;
    end;

    if accented then
      {if the last iteration found n = 195, it means we have an accented character. Print it and go to next iteration}
    begin
      dict_p^ := d3;
      decr := 159;
      n := Ord(Line[Count]);
      if n < 160 then
        {if it's a capital letter, put the caps signal and change to minuscule}
      begin
        Braille_string := Braille_string + caps_signal;
        n := n + 32;
      end;
      Braille_string := Braille_string + chr($e2) + chr($a0) + (dict_p^)[n - decr];
      accented := False;
      Count := Count + 1;
      continue;
    end;

    n := Ord(Line[Count]);

    if ((n >= 97) and (n <= 122)) then      {if the char is a letter, choose d2}
    begin
      dict_p^ := d2;
      decr := 96;
    end
    else
    if n = 195 then      {if the char is an accented letter, flag it and go to next iteration}
    begin
      accented := True;
      Count := Count + 1;
      continue;
    end

    else
    if ((n >= 65) and (n <= 90)) then
      {if it's a capital letter, choose d2 and see if it's only the first letter or if there are more capital letters}
    begin
      dict_p^ := d2;
      decr := 96 - 32;
      string_aux := chr($e2) + chr($a0) + (dict_p^)[n - decr];
      count_aux := Count + 1;
      if count_aux > length(Line) then
      begin
        Braille_string := Braille_string + caps_signal + string_aux;
        break;
      end;
      n_aux := Ord(Line[count_aux]);
      while ((n_aux >= 65) and (n_aux <= 90)) do
      begin
        string_aux := string_aux + chr($e2) + chr($a0) + (dict_p^)[n_aux - decr];
        count_aux := count_aux + 1;
        if count_aux > length(Line) then
          break;
        n_aux := Ord(Line[count_aux]);
      end;
      if length(string_aux) > 3 then
        Braille_string := Braille_string + caps_signal + caps_signal + string_aux
      else
        Braille_string := Braille_string + caps_signal + string_aux;
      Count := count_aux;
      continue;
    end
    else      {or else, choose d1}
    begin
      dict_p^ := d1;
      decr := 32;
    end;

    if num and not (((n >= 48) and (n <= 57)) or (n = 46) or (n = 44)) then
      {if the whole number has already been printed, change num to False again}
      num := False;

    if not num and ((n >= 48) and (n <= 57)) then
      {if it's the first number to appear, print the number signal first}
    begin
      Braille_string := Braille_string + number_signal;
      num := True;
    end;

    Braille_string := Braille_string + chr($e2) + chr($a0) + (dict_p^)[n - decr];

    Count := Count + 1;
  end;

  Result := Braille_string;
end;

function ConvertUTF8HtmlTextToBraille(AInput: string): string;
var
  i: integer;
  output, aux_string: string;
  is_text: boolean;
  page: string;
begin
  page := AInput;
  i := 1;
  output := '';
  aux_string := '';
  is_text := True;

  while i <= length(page) do
  begin
    while is_text and (i <= length(page)) do
    begin
      if (page[i] = '<') or (page[i] = '/') then
      begin
        is_text := False;
        break
      end;
      aux_string := aux_string + page[i];
      i := i + 1;
    end;

    output := output + ConvertUTF8TextToBraille(aux_string);

    while (not is_text) and (i <= length(page))do
    begin
      if (page[i] = '>') then
      begin
        is_text := True;
        i := i + 1;
        output := output + '>';
        break
      end;
      output := output + page[i];
      i := i + 1;
    end;
  end;

  ConvertUTF8HtmlTextToBraille := output;

end;

{ TBrailleBrowserModule }

constructor TBrailleBrowserModule.Create;
begin
  inherited Create;

  ShortDescription := 'Braille Module';
end;

function TBrailleBrowserModule.HandleOnPageLoad(AInput: string; out
  AOutput: string): Boolean;
begin
  AOutput := ConvertUTF8HtmlTextToBraille(AInput);
end;

initialization
  RegisterBrowserModule(TBrailleBrowserModule.Create());
end.