% ----------------------------------------------------------------
% LaTeXbangla package - Writing Bangla & Assamese with ordinary LaTeX
% E-mail: latexbangla@googlegroups.com
% Released under the LaTeX Project Public License v1.3c or later
% See https://www.latex-project.org/lppl.txt
% ----------------------------------------------------------------
% This package simplifies writing Bangla or Assamese documents in LaTeX.
% It provides automatic font switching between the selected language and Latin
% text, localized labels and numbering, and integration with supported packages.
% Authors can use ordinary LaTeX commands with either language alongside English.
% See the manual for configuration, examples, and supported features.
% ------------------------------------------------------------------
% Copyright (C) 2016, 2026 by Adib Hasan <latexbangla@googlegroups.com>

% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License (LPPL), either
% version 1.3c of this license or (at your option) any later
% version. The latest version of this license is in the file:

% https://www.latex-project.org/lppl.txt

% This work has the LPPL maintenance status "maintained".
% The current maintainer is Adib Hasan.

% This work consists of latexbangla.sty, the TeX and Lua files under code/,
% latexbangla-*.lbx, *natbn.bst and their .mbs/.ins source under code/references/,
% the manual source latexbangla.tex, its PDF,
% and logo.png.
% ------------------------------------------------------------------

% Minimum versions follow the final updated TeX Live 2024 distribution.
\NeedsTeXFormat{LaTeX2e}[2024-11-01]
\RequirePackage{iftex}
\RequireTUTeX
\ProvidesExplPackage{latexbangla}{2026-10-24}{2.1}
  {Bangla and Assamese support for XeLaTeX and LuaLaTeX}

% Polyglossia owns language data and decimal numbering; fontspec owns fonts.
% amstext is the small, style-aware text-in-math component, not the AMS suite.
\RequirePackage{fontspec}[2024/05/11]
\RequirePackage{polyglossia}[2025/01/31]
\RequirePackage{amstext}

\bool_new:N \g__latexbangla_convert_counters_bool
\bool_gset_true:N \g__latexbangla_convert_counters_bool
\tl_new:N \g__latexbangla_language_tl
\tl_gset:Nn \g__latexbangla_language_tl {bengali}
\tl_new:N \g__latexbangla_legacy_main_font_tl
\tl_new:N \g__latexbangla_legacy_mono_font_tl

\msg_new:nnn {latexbangla} {removed-feature}
  {The~'feature'~option~has~been~removed.\iow_newline:
   Remove~feature=#1.~Language~support~is~automatic;~define~your~own\iow_newline:
   environments~or~use~a~book~style.~See~the~migration~section~of~the~manual.}
\msg_new:nnn {latexbangla} {missing-font}
  {No~Bangla~main~font~was~configured.\iow_newline:
   Add~\token_to_str:N\setbanglamainfont{Your~font}~in~the~preamble.}
\msg_new:nnn {latexbangla} {empty-font}
  {The~Bangla~font~name~must~not~be~empty.~Pass~a~font~name~to~the~setter.}
\msg_new:nnn {latexbangla} {non-bengali-font}
  {The~font~'#1'~does~not~provide~the~tested~Bengali~glyph.\iow_newline:
   Choose~a~font~with~Bengali~coverage~for~the~Bangla~font~setter.}
\msg_new:nnn {latexbangla} {incomplete-assamese-font}
  {The~font~'#1'~does~not~provide~the~required~Assamese~letters~ka,~ra~and~wa.\iow_newline:
   Choose~a~font~with~Assamese~coverage~for~this~font~setter.}
\msg_new:nnn {latexbangla} {preamble-only}
  {Bangla~font~setters~must~be~used~before~\token_to_str:N\begin{document}.}

% Two font options survive for source compatibility. Numbering is a current
% option; accept 0/1 as aliases because published documents used those values.
\keys_define:nn {latexbangla}
  {
    language .choice:,
    language / bangla .code:n =
      \tl_gset:Nn \g__latexbangla_language_tl {bengali},
    language / assamese .code:n =
      \tl_gset:Nn \g__latexbangla_language_tl {assamese},
    language .value_required:n = true,
    banglamainfont .code:n =
      {\tl_if_blank:nTF {#1}
        {\msg_error:nn {latexbangla} {empty-font}}
        {\tl_gset:Nn \g__latexbangla_legacy_main_font_tl {#1}}},
    banglamainfont .value_required:n = true,
    banglattfont .code:n =
      {\tl_if_blank:nTF {#1}
        {\msg_error:nn {latexbangla} {empty-font}}
        {\tl_gset:Nn \g__latexbangla_legacy_mono_font_tl {#1}}},
    banglattfont .value_required:n = true,
    changecounternumbering .choice:,
    changecounternumbering / true .code:n =
      \bool_gset_true:N \g__latexbangla_convert_counters_bool,
    changecounternumbering / false .code:n =
      \bool_gset_false:N \g__latexbangla_convert_counters_bool,
    changecounternumbering / 1 .meta:n = {changecounternumbering=true},
    changecounternumbering / 0 .meta:n = {changecounternumbering=false},
    changecounternumbering .default:n = true,
    feature .code:n = \msg_fatal:nnn {latexbangla} {removed-feature} {#1},
  }
\ProcessKeyOptions[latexbangla]

% Select the document language before configuring fonts and integrations.
\file_input:n {code/languages/latexbangla-language.tex}

% Each file has one responsibility. They share the latexbangla namespace and
% deliberately keep upstream compatibility details in their respective module.
\file_input:n {code/latexbangla-fonts.tex}
\file_input:n {code/latexbangla-font-selection.tex}
\sys_if_engine_xetex:TF
  {\file_input:n {code/engines/latexbangla-engine-xetex.tex}}
  {\file_input:n {code/engines/latexbangla-engine-luatex.tex}}
\file_input:n {code/latexbangla-numbering.tex}
\file_input:n {code/latexbangla-math-digits.tex}
\file_input:n {code/references/latexbangla-bibliography.tex}
\file_input:n {code/languages/latexbangla-bibliography-bengali.tex}
\file_input:n {code/languages/latexbangla-bibliography-assamese.tex}
\file_input:n {code/references/latexbangla-natbib.tex}
\file_input:n {code/references/latexbangla-references.tex}

% Legacy options use exactly the same setters as new documents. Explicit
% setters later in the preamble therefore override the corresponding option.
\tl_if_empty:NF \g__latexbangla_legacy_main_font_tl
  {\exp_args:NV \setbanglamainfont \g__latexbangla_legacy_main_font_tl}
\tl_if_empty:NF \g__latexbangla_legacy_mono_font_tl
  {\exp_args:NV \setbanglamonofont \g__latexbangla_legacy_mono_font_tl}

\ExplSyntaxOff
\endinput