% --------------------------------------------------------------------------
%
% the CHEMMACROS package -- module: `lang'
%
% --------------------------------------------------------------------------
% Clemens Niederberger
% --------------------------------------------------------------------------
% https://github.org/cgnieder/chemmacros/
% contact@mychemistry.eu
% --------------------------------------------------------------------------
% If you have any ideas, questions, suggestions or bugs to report, please
% feel free to contact me.
% --------------------------------------------------------------------------
% Copyright 2011-2017 Clemens Niederberger
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3
% of this license or (at your option) any later version.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.3 or later is part of all distributions of LaTeX
% version 2005/12/01 or later.
%
% This work has the LPPL maintenance status `maintained'.
%
% The Current Maintainer of this work is Clemens Niederberger.
% --------------------------------------------------------------------------
\ChemModule{lang}{2016/05/31 language settings for chemmacros}

\RequirePackage{translations}

\msg_new:nnn {chemmacros} {language-not-defined}
  {
    You~ chose~ the~ language~ `#1'~ which~ is~ not~ defined~ by~ chemmacros.~
    `english'~ is~ used~ instead.~ If~ you~ just~ mistyped~ try~ again!~
    Otherwise~ contact~ the~ author~ and~ he'll~ probably~ add~ your~ language.
  }

% --------------------------------------------------------------------------
% language settings:
\bool_new:N      \l__chemmacros_language_auto_bool
\bool_set_true:N \l__chemmacros_language_auto_bool
% this token list will hold the chosen language for chemmacros; since the
% language is either chosen automatically or by option it is only available at
% begin document
\tl_new:N  \l_chemmacros_language_tl
\tl_set:Nn \l_chemmacros_language_tl {english}
\tl_new:N  \l__chemmacros_current_language_tl

\tl_const:Nx \c__chemmacros_keyword_prefix_tl
  { \chemmacros_if_compatibility:nnT {>=} {5.7} {chem-keyword-} }

\prop_new:N \g_chemmacros_translations_prop

% translate the key #1
\cs_new:Npn \chemmacros_translate:n #1
  {
    \bool_if:NTF \l__chemmacros_language_auto_bool
      { \GetTranslation { \c__chemmacros_keyword_prefix_tl #1 } }
      {
        \GetTranslationFor
          {\l_chemmacros_language_tl}
          { \c__chemmacros_keyword_prefix_tl #1 }
      }
  }

\DeclareExpandableDocumentCommand \ChemTranslate {m}
  { \chemmacros_translate:n {#1} }

\chemmacros_define_global_keys:n
  {
    language .value_required:n = true ,
    language .code:n =
      \tl_if_eq:nnTF {#1} {auto}
        { \bool_set_true:N \l__chemmacros_language_auto_bool }
        {
          \bool_set_false:N \l__chemmacros_language_auto_bool
          \tl_set:Nn \l__chemmacros_current_language_tl {#1}
        } ,
    language .initial:n = auto
  }

\ChemCompatibilityTo{5.3}
\chemmacros_define_global_keys:n
  {
    german   .meta:n = { language = german } ,
    ngerman  .meta:n = { language = ngerman }
  }
\EndChemCompatibility

\AtBeginDocument{
  \bool_if:NTF \l__chemmacros_language_auto_bool
    {
      \tl_set:Nx \l_chemmacros_language_tl
        { \@trnslt@language{\@trnslt@current@language} }
    }
    {
      \tl_set_eq:NN
        \l_chemmacros_language_tl
        \l__chemmacros_current_language_tl
    }   
}

% --------------------------------------------------------------------------
\cs_new_protected:Npn \__chemmacros_declare_translation:nw #1#2=#3\q_stop
  {
    \tl_set:Nx \l__chemmacros_tmpa_tl { \tl_trim_spaces:n {#2} }
    \tl_set:Nx \l__chemmacros_tmpb_tl { \tl_trim_spaces:n {#3} }
    \use:x
      {
        \chemmacros_declare_translation:nnn
          { \exp_not:n {#1} }
          { \exp_not:V \l__chemmacros_tmpa_tl }
          { \exp_not:V \l__chemmacros_tmpb_tl }
      }
  }

% #1: key
% #2: lang
% #3: translation
\cs_new_protected:Npn \chemmacros_declare_translation:nnn #1#2#3
  {
    \declaretranslation
      {#2}
      { \c__chemmacros_keyword_prefix_tl #1 }
      {#3}
    \prop_gput:Nnn \g_chemmacros_translations_prop {#1(#2)} {#3}
  }
\cs_generate_variant:Nn \chemmacros_declare_translation:nnn {V}

% #1: key
% #2: csv list: { <lang1> = <translation1> , <lang2> = <translation2> }
\cs_new_protected:Npn \chemmacros_declare_translations:nn #1#2
  {
    \clist_map_inline:nn {#2}
      { \__chemmacros_declare_translation:nw {#1} ##1 \q_stop }
  }

\NewDocumentCommand \DeclareChemTranslations {mm}
  { \chemmacros_declare_translations:nn {#1} {#2} }
\@onlypreamble \DeclareChemTranslations
  
\NewDocumentCommand \DeclareChemTranslation {mmm}
  { \chemmacros_declare_translation:nnn {#1} {#2} {#3} }
\@onlypreamble \DeclareChemTranslation

\cs_new:Npn \__chemmacros_parse_translate_list_entry:nnn #1#2#3 {}

\cs_new_protected:Npn \__chemmacros_parse_translate_list_entry:www #1(#2)\q_mark#3\q_stop
  { \__chemmacros_parse_translate_list_entry:nnn {#1} {#2} {#3} }

\cs_new_protected:Npn \chemmacros_for_all_translations_do:n #1
  {
    \cs_set:Npn \__chemmacros_parse_translate_list_entry:nnn ##1##2##3 {#1}
    \prop_map_inline:Nn \g_chemmacros_translations_prop
      { \__chemmacros_parse_translate_list_entry:www ##1 \q_mark ##2 \q_stop }
  }

\ChemCompatibilityFrom{5.7}
\NewDocumentCommand \ForAllChemTranslationsDo {+m}
  { \chemmacros_for_all_translations_do:n {#1} }
\EndChemCompatibility

% --------------------------------------------------------------------------
\tex_endinput:D

2015/11/17 - remove options `german' and `ngerman', starting with v5.3
2016/02/03 - adapt to changes in `acid-base' module
2016/04/27 - additions/changes to reaction and scheme translations
           - \chemmacros_declare_translation:nnn and
             \chemmacros_declare_translations:nn
           - \DeclareChemTranslation and \DeclareChemTranslations
           - moved translations from lang module to the corresponding modules
             they belong to
2016/05/31 - add prefix string to translation keywords
           - add logging of translation keywords
           - \ForAllChemTranslationsDo
