% --------------------------------------------------------------------------
%
% the CHEMMACROS package -- module: `greek'
%
% --------------------------------------------------------------------------
% 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{greek}{2015/06/09 upright greek symbols}

\RequirePackage{chemgreek}[2015/04/09]

\msg_new:nnn {chemmacros} {no-greek}
  {
    You~ haven't~ loaded~ any~ package~ for~ upright~ Greek~ letters~ or~ no~
    unique~ choice~ was~ possible.~ Either~ load~ one~ of~ packages~
    specified~ in~ the~ manual~ or~ select~ a~ chemgreek~ mapping~ manually.
  }

\msg_new:nnn {chemmacros} {greek-undefined}
  {
    The~ chemgreek~ mapping~ `#1'~ you~ chose~ \msg_line_context: \c_space_tl
    is~ not~ defined.~ Please~ choose~ another~ one.
  }

% chemgreek selects a mapping if an unambiguous choice is possible, otherwise
% selects `default'. Warn the user in this case:
\AtBeginDocument{
  \bool_if:nT
    {
      \chemgreek_if_mapping_active_p:n {default} ||
      \chemgreek_if_mapping_active_p:n {var-default}
    }
    { \msg_warning:nn {chemmacros} {no-greek} }
}

% an option for manual selection:
\chemmacros_define_global_keys:n
  {
    greek .code:n = \chemmacros_choose_chemgreek_mapping:n {#1}
  }

\cs_new_protected:Npn \chemmacros_choose_chemgreek_mapping:n #1
  {
    \chemgreek_if_mapping_exists:nTF {#1}
      {
        \chemgreek_load_mapping_package:n {#1}
        \chemgreek_activate_mapping:n {#1}
      }
      { \msg_warning:nnn {chemmacros} {greek-undefined} {#1} }
  }

% --------------------------------------------------------------------------