% --------------------------------------------------------------------------
%
% the CHEMMACROS package -- module: `reactions'
%
% --------------------------------------------------------------------------
% 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 2011-2015 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{reactions}{2015/07/14 reaction environments}

\chemmacros_load_module:n {chemformula}

\RequirePackage{mathtools}

% --------------------------------------------------------------------------
\cs_new_protected:Npn \__chemmacros_record_for_lor:nnnnn #1#2#3#4#5
  {
    \tl_if_eq:nnT { #1 } { reaction }
      {
        \group_begin:
          % we need to prevent \Hy@make@anchor from being written to the lor
          % file:
          \bool_if:NT \l__chemmacros_hyperref_bool
            { \cs_set:Npn \Hy@make@anchor {} }
          \addcontentsline { lor } { reaction }
            {
              \tl_use:N \l__chemmacros_reaction_lorname_tl
              \tl_use:N \c_space_tl
              #2 #3 #4 #5
              \tl_use:N \g__chemmacros_reaction_description_tl
            }
          \tl_gclear:N \g__chemmacros_reaction_description_tl
        \group_end:
      }
  }

% redefine mathtools' command \MT_define_tagform:nwnn to ensure we add an
% entry to the list of reactions even if the user redefines the reaction tag
% this should probably be done via patching...
\AfterPackage* { mathtools }
  {
    \cs_set_protected:Npn \MT_define_tagform:nwnn #1[#2]#3#4
      {
        \@namedef{MT_tagform_#1:n}##1
          {
            % this is the original part:
            \maketag@@@{#3\ignorespaces#2{##1}\unskip\@@italiccorr#4}
            % this is added => this disturbs hyperref:
            \__chemmacros_record_for_lor:nnnnn
              { #1 } { #3 } { #2 } { ##1 } { #4 }
          }
      }
  }

\tl_new:N \g__chemmacros_reaction_description_tl

\cs_new_protected:Npn \chemmacros_add_reaction_description:n #1
  {
    \tl_if_blank:nF { #1 }
      { \tl_gset:Nn \g__chemmacros_reaction_description_tl { : ~ #1 } }
  }

\NewDocumentCommand \AddRxnDesc { m }
  { \chemmacros_add_reaction_description:n { #1 } }

% define \listofreactions
\tl_new:N  \l__chemmacros_reaction_lorname_tl
\tl_new:N  \reactionlistname
\tl_new:N  \l__chemmacros_reaction_heading_tl

\cs_if_exist:NTF \chapter
  { \tl_set:Nn \l__chemmacros_reaction_heading_tl { \chapter* } }
  { \tl_set:Nn \l__chemmacros_reaction_heading_tl { \section* } }

\tl_set:Nn \l__chemmacros_reaction_lorname_tl { \chemmacros_translate:n {reaction} }
\tl_set:Nn \reactionlistname { \chemmacros_translate:n {list-of-reactions} }

\cs_new:Npn \__chemmacros_reaction_heading:n #1
  { \l__chemmacros_reaction_heading_tl { #1 } }
\cs_generate_variant:Nn \__chemmacros_reaction_heading:n { V }

\cs_new_protected:Npn \listofreactions
  {
    \__chemmacros_reaction_heading:V \reactionlistname
    \@starttoc { lor }
  }

\cs_new_protected:Npn \l@reaction #1#2
  { \@dottedtocline { 1 } { 1.5em } { 2.3em } { #1 } { #2 } }

% create new tagform
\newtagform {reaction} {\{} {\}}
\newcounter {chemmacros_save_reaction}
\newcounter {reaction}

\cs_new_protected:Npn \__chemmacros_begin_reaction:
  {
    % create individual names for `hyperref':
    \bool_if:NT \l__chemmacros_hyperref_bool
      {
        \cs_set:Npn \theHequation
          { R . \theHsection . \arabic {reaction} }
      }
    % enable labelformat `reaction':
    \bool_if:NT \l__chemmacros_varioref_bool
      { \cs_set_eq:NN \p@equation \p@reaction }
    \setcounter {chemmacros_save_reaction} { \value {equation} }
    \setcounter {equation} { \value {reaction} }
    \usetagform {reaction}
  }

% switch back to equation tags
\cs_new_protected:Npn \__chemmacros_end_reaction:
  {
    \setcounter {reaction} { \value {equation} }
    \setcounter {equation} { \value {chemmacros_save_reaction} }
  }

\tl_new:N \l__chemmacros_reactions_args_tl

\cs_new_protected:Npn \__chemmacros_reactions_build_args:n #1
  { \tl_put_right:Nn \l__chemmacros_reactions_args_tl { {## #1} } }

\cs_new_protected:Npn \chemmacros_define_reaction:nnn #1#2#3
  {
    \int_compare:nNnT {#3+0} > {0}
      {
        \tl_clear:N \l__chemmacros_reactions_args_tl
        \int_step_function:nnnN {2} {1} {#3+1} \__chemmacros_reactions_build_args:n
      }
    \chemmacros_reaction_env:nnnV {#1} {#2} {#3} \l__chemmacros_reactions_args_tl
  }

% #1: chem
% #2: math
% #3: args number
% #4: argument list ({#2}{#3}...)
\cs_new_protected:Npn \chemmacros_reaction_env:nnnn #1#2#3#4
  {
    \exp_args:Nnx \DeclareDocumentEnvironment {#1} { O{} \prg_replicate:nn {#3+0} {m} }
      {
        \chemmacros_add_reaction_description:n {##1}
        \__chemmacros_begin_reaction:
        \chemmacros_reaction_read:nnw {#2} {#4}
      }
      { \__chemmacros_end_reaction: }
  }
\cs_generate_variant:Nn \chemmacros_reaction_env:nnnn {nnnV}
  
\cs_new_protected:Npn \chemmacros_reaction_read:nnw #1#2#3 \end
  {
    \begin{#1}#2
      \chemformula_ch:nn {} {#3}
    \end{#1}
    \end
  }

\chemmacros_new_environment_macroset:nnn {Reaction} {mO{}m}
  { \chemmacros_define_reaction:nnn {#1} {#3} {#2} }

\NewChemReaction {reaction}   {equation}
\NewChemReaction {reaction*}  {equation*}
\NewChemReaction {reactions}  {align}
\NewChemReaction {reactions*} {align*}

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