% --------------------------------------------------------------------------
% the CHEMMACROS package
%
%   comprehensive support for typesetting chemistry documents
%
% --------------------------------------------------------------------------
% 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--2020 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.
% --------------------------------------------------------------------------
\RequirePackage{expl3,xparse,l3keys2e}
\ExplSyntaxOn

% --------------------------------------------------------------------------
% package information:
\tl_const:Nn \c_chemmacros_date_tl {2020/03/07}
\tl_const:Nn \c_chemmacros_version_major_number_tl {5}
\tl_const:Nn \c_chemmacros_version_minor_number_tl {11}
\tl_const:Nn \c_chemmacros_version_subrelease_tl   {}
\tl_const:Nx \c_chemmacros_version_number_tl
  {
    \c_chemmacros_version_major_number_tl .
    \c_chemmacros_version_minor_number_tl
  }
\tl_const:Nx \c_chemmacros_version_tl
  {
    \c_chemmacros_version_number_tl
    \c_chemmacros_version_subrelease_tl
  }
\tl_const:Nn \c_chemmacros_info_tl
  {comprehensive~ support~ for~ typesetting~ chemistry~ documents}

\ProvidesExplPackage
  {chemmacros}
  {\c_chemmacros_date_tl}
  {\c_chemmacros_version_tl}
  {\c_chemmacros_info_tl \c_space_tl (CN)}

% --------------------------------------------------------------------------
% set compatibility
\tl_new:N \l__chemmacros_compatibility_version_tl
\tl_set_eq:NN \l__chemmacros_compatibility_version_tl \c_chemmacros_version_tl

\keys_define:nn {chemmacros/compatibility}
  {
    compatibility .code:n =
      \str_case:nnTF {#1}
        {
          {newest} {}
          {latest} {}
        }
        {
          \tl_set_eq:NN
            \l__chemmacros_compatibility_version_tl
            \c_chemmacros_version_tl
        }
        { \tl_set:Nn \l__chemmacros_compatibility_version_tl {#1} } ,
    unknown       .code:n =
      \PassOptionsToPackage{\CurrentOption}{chemmacros4}
      \PassOptionsToPackage{\CurrentOption}{chemmacros5}
  }

\ProcessKeysPackageOptions {chemmacros/compatibility}

% --------------------------------------------------------------------------
% compare version numbers
% #1: version
% #2: relation
% #3: version
% #4: true
% #5: false
\prg_new_conditional:Npnn \chemmacros_if_version:nnn #1#2#3 {p,T,F,TF}
  {
    \fp_compare:nTF
      {
        (
          \chemmacros_get_major_version:n {#1} * 1e6 +
          \chemmacros_get_minor_version:n {#1} * 1e3 +
          0 \chemmacros_get_subrelease:n {#1}
        )
        #2
        (
          \chemmacros_get_major_version:n {#3} * 1e6 +
          \chemmacros_get_minor_version:n {#3} * 1e3 +
          0 \chemmacros_get_subrelease:n {#3}
        )
      }
      { \prg_return_true: }
      { \prg_return_false: }
  }
\cs_generate_variant:Nn \chemmacros_if_version:nnnTF {fnf}

\cs_new:Npn \__chemmacros_get_minor_version:w #1.#2.#3 \q_stop
  {
    \tl_if_blank:nTF {#2} {0} {
       \tl_map_function:nN {#2} \__chemmacros_get_minor_number:n
    }
  }

\cs_new:Npn \chemmacros_get_minor_version:n #1
  { \__chemmacros_get_minor_version:w #1.. \q_stop }

\cs_new:Npn \__chemmacros_get_minor_number:n #1
  {
    \str_case:nn {#1}
      {
        {0} {0}
        {1} {1}
        {2} {2}
        {3} {3}
        {4} {4}
        {5} {5}
        {6} {6}
        {7} {7}
        {8} {8}
        {9} {9}
      }
  }

\cs_new:Npn \__chemmacros_get_major_version:w #1.#2.#3 \q_stop
  { \tl_if_blank:nTF {#1} {0} {#1} }

\cs_new:Npn \chemmacros_get_major_version:n #1
  { \__chemmacros_get_major_version:w #1.. \q_stop }

\cs_new:Npn \__chemmacros_get_subrelease:w #1.#2.#3 \q_stop
  {
    \tl_if_blank:nTF {#2} {0} {
       \tl_map_function:nN {#2} \__chemmacros_get_subrelease_number:n
    }
  }

\cs_new:Npn \chemmacros_get_subrelease:n #1
  { \__chemmacros_get_subrelease:w #1.. \q_stop }

\cs_new:Npn \__chemmacros_get_subrelease_number:n #1
  {
    \str_case:nnF {#1}
      {
        {0} {}
        {1} {}
        {2} {}
        {3} {}
        {4} {}
        {5} {}
        {6} {}
        {7} {}
        {8} {}
        {9} {}
      }
      { \int_from_alph:n {#1} }
  }

% check compatibility
% #1: relation
% #2: number
% #3: true
% #4: false
\prg_new_conditional:Npnn \chemmacros_if_compatibility:nn #1#2 {p,T,F,TF}
  {
    \chemmacros_if_version:fnfTF
      { \l__chemmacros_compatibility_version_tl }
      {#1}
      {#2}
      { \prg_return_true: }
      { \prg_return_false: }
  }
\cs_generate_variant:Nn \chemmacros_if_compatibility:nnT {nV}

% user checks:
\NewExpandableDocumentCommand \IfChemCompatibilityTF {mm+m+m}
  { \chemmacros_if_compatibility:nnTF {#1} {#2} {#3} {#4} }

\NewExpandableDocumentCommand \IfChemCompatibilityT {mm+m}
  { \chemmacros_if_compatibility:nnT {#1} {#2} {#3} }

\NewExpandableDocumentCommand \IfChemCompatibilityF {mm+m}
  { \chemmacros_if_compatibility:nnF {#1} {#2} {#3} }

% --------------------------------------------------------------------------
% compatibility coding:
\cs_new_protected:Npn \ChemCompatibility #1#2 \EndChemCompatibility
  { \chemmacros_if_compatibility:nnT {=} {#1} {#2} }
  
\cs_new_protected:Npn \ChemCompatibilityFrom #1#2 \EndChemCompatibility
  { \chemmacros_if_compatibility:nnT {>=} {#1} {#2} }

\cs_new_protected:Npn \ChemCompatibilityTo #1#2 \EndChemCompatibility
  { \chemmacros_if_compatibility:nnT {<} {#1} {#2} }

\cs_new_protected:Npn \ChemCompatibilityBetween #1#2#3 \EndChemCompatibility
  {
    \bool_lazy_and:nnT
      { \chemmacros_if_compatibility_p:nn {>=} {#1} }
      { \chemmacros_if_compatibility_p:nn {<} {#2} }
      {#3}
  }

% --------------------------------------------------------------------------
% messages:
\msg_new:nnn {chemmacros} {too-low-compatibility}
  {
    Compatibility~ for~ versions~ below~ v4.7~ is~ not~ supported!~ You~
    requested~ version~ v #1.~ Loading~ v4.7~ instead.
  }

\msg_new:nnn {chemmacros} {too-high-compatibility}
  {
    You~ requested~ compatibility~ mode~ v #1~ while~ the~ current~ version~
    of~ chemmacros~ is~ v \c_chemmacros_version_tl .~ Falling~ back~
    to~ v \c_chemmacros_version_number_tl !
  }

\msg_new:nnn {chemmacros} {low-compatibility}
  {
    You~ requested~ compatibility~ mode~ v #1~ while~ the~ current~ version~
    of~ chemmacros~ is~ v \c_chemmacros_version_tl .~ Not~ all~ features~
    or~ fixes~ will~ be~ available!
  }

% --------------------------------------------------------------------------
% let's see that the max number is the newest (=current) version
\chemmacros_if_compatibility:nnT {>} { \c_chemmacros_version_tl }
  {
    \tl_set_eq:NN
      \l__chemmacros_compatibility_version_tl
      \c_chemmacros_version_tl
  }

% --------------------------------------------------------------------------
% compatibility too low:
\chemmacros_if_compatibility:nnT {<} {4.7}
  {
    \msg_warning:nnx {chemmacros} {too-low-compatibility}
      { \l__chemmacros_compatibility_version_tl }
  }

% not the newest version:
\chemmacros_if_compatibility:nnT {<} { \c_chemmacros_version_tl }
  {
    \msg_warning:nnx {chemmacros} {low-compatibility}
      { \l__chemmacros_compatibility_version_tl }
  }
  
% --------------------------------------------------------------------------
\chemmacros_if_compatibility:nnTF {<} {5.0}
  { \RequirePackage{chemmacros4} }
  { \RequirePackage{chemmacros5} }

\file_input_stop: