% Language definition file (part of polyglossia v2.2 -- 2024/07/15)
%
\ProvidesFile{gloss-thai.ldf}[polyglossia: module for Thai]
%% This is partly based on thai-latex for Babel:
%%%% Copyright (C) 1999 - 2006
%%%%           by Surapant Meknavin,
%%%%              Theppitak Karoonboonyanan (thep at linux.thai.net),
%%%%              Chanop Silpa-Anan (chanop at debian.org),
%%%%              Poonlap Veerathanabutr (poonlap at linux.thai.net)
%%%%              Thai Linux Working Group
%%%%              http://linux.thai.net/
%%%%
\PolyglossiaSetup{thai}{
  bcp47=th,
  bcp47-language=th,
  bcp47-script=Thai,
  script=Thai,
  scripttag=thai,
  langtag=THA,
  hyphennames={nohyphenation},
  fontsetup=true,
  localnumeral=thainumerals
  %TODO localalph={xxx@alph,xxx@Alph}
  %TODO localdigits=thainumber
}

% BCP-47 compliant aliases
\setlanguagealias*{thai}{th}

\newif\if@thai@numerals
\def\tmp@thai{thai}

\DeclareKeys[polyglossia/gloss/thai]
  {
    numerals.choice:,
    numerals / arabic.code =
      {%
        \@thai@numeralsfalse
        \SetLanguageKeys{thai}{bcp47-extension-u=nu-latn}%
      },
    numerals / thai.code =
      {%
        \@thai@numeralstrue
        \SetLanguageKeys{thai}{bcp47-extension-u=nu-thai}%
      },
    numerals.default:n = arabic,
  }

% Register default options
\InitializeGlossOptions{thai}{numerals=arabic}

\def\captionsthai{%
   \def\refname{หนังสืออ้างอิง}%
   \def\abstractname{บทคัดย่อ}%
   \def\bibname{บรรณานุกรม}%
   \def\prefacename{คำนำ}%
   \def\chaptername{บทที่}%
   \def\appendixname{ภาคผนวก}%
   \def\contentsname{สารบัญ}%
   \def\listfigurename{สารบัญรูป}%
   \def\listtablename{สารบัญตาราง}%
   \def\indexname{ดรรชนี}%
   \def\figurename{รูปที่}%
   \def\tablename{ตารางที่}%
   %\def\thepart{}%
   \def\partname{ภาค}%
   \def\pagename{หน้า}%
   \def\seename{ดู}%
   \def\alsoname{ดูเพิ่มเติม}%
   \def\enclname{สิ่งที่แนบมาด้วย}%
   \def\ccname{สำเนาถึง}%
   \def\headtoname{เรียน}%
   \def\proofname{พิสูจน์}%
   %\def\glossaryname{}%
}
\def\datethai{%   
   \def\thai@month{%
     \ifcase\month\or
       มกราคม\or กุมภาพันธ์\or มีนาคม\or เมษายน%
      \or พฤษภาคม\or มิถุนายน\or กรกฎาคม\or สิงหาคม%
      \or กันยายน\or ตุลาคม\or พฤศจิกายน\or ธันวาคม\fi}%
   \newcount\thai@year%
   \thai@year=\year%
   \advance\thai@year by 543%
   \def\today{\thainumber\day \space \thai@month\space พ.ศ.~\thainumber\thai@year}%
}

%NB: thai-latex had "plus 0.6pt", but .4em appears to give better results
% FIXME to avoid name clashes, rename \wbr to \wordbreak or \thaiworkbreak ?
\def\wbr{\hskip0pt plus .4em\relax} %%OR \char"200B = ZWSP ? Does not work
%\catcode"200b=\active
%\def^^200b{\hskip 0pt plus .4em}

\def\thaidigits#1{\expandafter\@thai@digits #1@}
\def\@thai@digits#1{%
  \ifx @#1% then terminate
  \else
    \ifx0#1๐\else\ifx1#1๑\else\ifx2#1๒\else\ifx3#1๓\else\ifx4#1๔\else\ifx5#1๕\else\ifx6#1๖\else\ifx7#1๗\else\ifx8#1๘\else\ifx9#1๙\else#1\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi
    \expandafter\@thai@digits
  \fi
}

\newcommand{\thainumerals}[2]{\thainumber{#2}}

\def\thainumber#1{%
  \if@thai@numerals
    \thaidigits{\number#1}%
    %%{\protect\addfontfeature{Mapping=thaidigits}\protect\number#1}
  \else
    \number#1%
    %%{\protect\reset@font\number#1}
  \fi}

\def\@thaialph#1{%
  \ifcase#1\or ก\or ข\or ค\or ง\or จ\or ฉ\or ช\or ซ\or ฌ\or ญ\or ฎ\or
   ฏ\or ฐ\or ฑ\or ฒ\or ณ\or ด\or ต\or ถ\or ท\or ธ\or น\or บ\or ป\or ผ\or
   ฝ\or พ\or ฟ\or ภ\or ม\or ย\or ร\or ล\or ว\or ศ\or ษ\or ส\or ห\or ฬ\or อ\or
   ฮ\else\xpg@ill@value{#1}{@thaialph}\fi}
\def\thaiAlph#1{\expandafter\@thaiAlph\csname c@#1\endcsname}
\def\@thaiAlph#1{%
  \ifcase#1\or ก\or ข\or ฃ\or ค\or ฅ\or ฆ\or ง\or จ\or ฉ\or ช\or ซ\or
   ฌ\or ญ\or ฎ\or ฏ\or ฐ\or ฑ\or ฒ\or ณ\or ด\or ต\or ถ\or ท\or ธ\or น\or
    บ\or ป\or ผ\or ฝ\or พ\or ฟ\or ภ\or ม\or ย\or ร\or ฤ\or ล\or ฦ\or ว\or
     ศ\or ษ\or ส\or ห\or ฬ\or อ\or ฮ\else\xpg@ill@value{#1}{@thaialph}\fi}
     
\def\thai@numbers{%
   \if@thai@numerals
     \let\@alph\@thaialph%
     \let\@Alph\@thaiAlph%
   \fi
}
\def\nothai@numbers{%
  \let\@alph\latin@alph%
  \let\@Alph\latin@Alph%
}

\def\thai@globalnumbers{%
   \let\orig@arabic\@arabic%
   \let\@arabic\thainumber%
   \renewcommand{\thefootnote}{\localnumeral*{footnote}}%
}
\def\nothai@globalnumbers{%
   \let\@arabic\orig@arabic%
}

\def\blockextras@thai{%
%%TODO \XeTeXlinebreaklocales "th"% uses ICU to find line breaks on the basis of a dictionary lookup-- make this optional? (in case a user might prefer a preprocessor
   \let\orig@baselinestrech\baselinestretch%
   \renewcommand{\baselinestretch}{1.2}%
}
\def\noblockextras@thai{%
%%TODO \XeTeXlinebreaklocales "en"%
   \let\baselinestrech\orig@baselinestretch%
}

\endinput

%TODO ?

%\def\thainum#1{\expandafter\thainumber\csname c@#1\endcsname}
%\def\thaibracenum#1{(\expandafter\thainumber\csname c@#1\endcsname)}
%\def\thaialph#1{\expandafter\@thaialph\csname c@#1\endcsname}

\@ifclassloaded{book}{%
  % redefine page numbering for frontmatter and mainmatter
  \def\ps@headnum{\let\@mkboth\@gobbletwo
       \def\@oddhead{\reset@font\hfil\thepage\hfil}\let\@oddfoot\@empty
       \let\@evenhead\@oddhead\let\@evenfoot\@empty}
  \let\@ltxfrontmatter\frontmatter
  \renewcommand\frontmatter{\@ltxfrontmatter\pagestyle{headnum}\pagenumbering{thaibracenum}}
  \let\@ltxmainmatter\mainmatter
  \renewcommand\mainmatter{\@ltxmainmatter\pagestyle{headings}\pagenumbering{thainum}}
}{}

\@ifclassloaded{book}{%
\renewcommand\appendix{\par
  \setcounter{chapter}{0}%
  \setcounter{section}{0}%
  \gdef\@chapapp{\appendixname}%
  \gdef\thechapter{\@thaialph\c@chapter}}
}{}
\@ifclassloaded{report}{%
\renewcommand\appendix{\par
  \setcounter{chapter}{0}%
  \setcounter{section}{0}%
  \gdef\@chapapp{\appendixname}%
  \gdef\thechapter{\@thaialph\c@chapter}}
}{}
\@ifclassloaded{article}{%
\renewcommand\appendix{\par
  \setcounter{section}{0}%
  \setcounter{subsection}{0}%
  \gdef\thesection{\@thaialph\c@section}}
}{}