% SPDX-License-Identifier: MIT
% Copyright (c) 2026 import-citation-cff contributors
\ProvidesFile{cfflatex-style-rsc.def}
  [import-citation-cff RSC author style]
\ExplSyntaxOn

% The article template of the Royal Society of Chemistry typesets its title
% block by hand in a @twocolumnfalse environment, without \maketitle, and lists
% the footnotes of the first page after the block with \footnotetext. This
% style defines two commands for them:
%   \rscauthors    Name,\textit{$^{*a}$} Name,\textit{$^{b\ddag}$} and Name...
%   \rscfootnotes  \footnotetext{\textit{$^{*}$~<contact>}} for each contact,
%                  then each affiliation (a, b, ...), then each note.
% Contacts are marked *, **, ..., and notes \ddag, \S, \P, \ddag\ddag, ...;
% the template keeps \dag for the electronic supplementary information. Authors
% with the same footnote text share its symbol. With one affiliation, no letter
% is needed.

% The authors as {<name>}{<marks>}, the footnotes as {<mark>}{<text>}, and the
% symbols of the footnote texts.
\seq_new:N \l__cfflatex_rsc_authors_seq
\seq_new:N \l__cfflatex_rsc_contacts_seq
\seq_new:N \l__cfflatex_rsc_affiliations_seq
\seq_new:N \l__cfflatex_rsc_notes_seq
\prop_new:N \l__cfflatex_rsc_symbols_prop
\int_new:N \l__cfflatex_rsc_contact_count_int
\int_new:N \l__cfflatex_rsc_note_count_int
% The marks of the current author by kind, its footnotes so far, and how many
% of its footnotes are contacts.
\seq_new:N \l__cfflatex_rsc_letters_seq
\tl_new:N \l__cfflatex_rsc_contact_marks_tl
\tl_new:N \l__cfflatex_rsc_note_marks_tl
\int_new:N \l__cfflatex_rsc_thanks_int
\int_new:N \l__cfflatex_rsc_contacts_int
\tl_new:N \l__cfflatex_rsc_text_tl
\tl_new:N \l__cfflatex_rsc_symbol_tl
\tl_new:N \l__cfflatex_rsc_authors_tl
\tl_new:N \l__cfflatex_rsc_footnotes_tl
\cs_generate_variant:Nn \prop_put:Nnn { NVV }

\cs_new_protected:Npn \__cfflatex_rsc_begin:
  {
    \seq_clear:N \l__cfflatex_rsc_authors_seq
    \seq_clear:N \l__cfflatex_rsc_contacts_seq
    \seq_clear:N \l__cfflatex_rsc_affiliations_seq
    \seq_clear:N \l__cfflatex_rsc_notes_seq
    \prop_clear:N \l__cfflatex_rsc_symbols_prop
    \int_zero:N \l__cfflatex_rsc_contact_count_int
    \int_zero:N \l__cfflatex_rsc_note_count_int
  }

% The marks of author #1 are the letters of its affiliations, then the
% footnotes of its contacts, then those of its notes. Footnotes are
% \__cfflatex_thanks:n, which only \maketitle sets, so they become symbols
% with footnotes of their own. The notes of the author tell how many of its
% footnotes are contacts.
\cs_new_protected:Npn \__cfflatex_rsc_prepare:n #1
  {
    \int_zero:N \l__cfflatex_rsc_contacts_int
    \seq_map_inline:Nn \l__cfflatex_marks_seq
      {
        \tl_if_head_eq_meaning:nNT {##1} \__cfflatex_thanks:n
          { \int_incr:N \l__cfflatex_rsc_contacts_int }
      }
    \seq_map_inline:Nn \l__cfflatex_notes_seq
      { \__cfflatex_rsc_count_note:nnn {#1} ##1 }
    \seq_clear:N \l__cfflatex_rsc_letters_seq
    \tl_clear:N \l__cfflatex_rsc_contact_marks_tl
    \tl_clear:N \l__cfflatex_rsc_note_marks_tl
    \int_zero:N \l__cfflatex_rsc_thanks_int
    \seq_map_inline:Nn \l__cfflatex_marks_seq
      {
        \tl_if_head_eq_meaning:nNTF {##1} \__cfflatex_thanks:n
          {
            \int_incr:N \l__cfflatex_rsc_thanks_int
            \tl_set:No \l__cfflatex_rsc_text_tl { \use_ii:nn ##1 }
            \int_compare:nNnTF { \l__cfflatex_rsc_thanks_int }
              > { \l__cfflatex_rsc_contacts_int }
              { \__cfflatex_rsc_note: }
              { \__cfflatex_rsc_contact: }
          }
          {
            \int_compare:nNnT { \cffaffiliationcount } > { 1 }
              { \seq_put_right:Nn \l__cfflatex_rsc_letters_seq {##1} }
          }
      }
    \tl_set:Ne \l__cfflatex_marks_tl
      {
        \exp_not:V \l__cfflatex_rsc_contact_marks_tl
        \seq_use:NV \l__cfflatex_rsc_letters_seq \l__cfflatex_separator_tl
        \exp_not:V \l__cfflatex_rsc_note_marks_tl
      }
  }
\cs_new_protected:Npn \__cfflatex_rsc_count_note:nnn #1#2#3
  {
    \int_compare:nNnT {#1} = {#2}
      { \int_decr:N \l__cfflatex_rsc_contacts_int }
  }
% Contacts are marked *, **, and so on.
\cs_new_protected:Npn \__cfflatex_rsc_contact:
  {
    \prop_get:NVNF \l__cfflatex_rsc_symbols_prop \l__cfflatex_rsc_text_tl
      \l__cfflatex_rsc_symbol_tl
      {
        \int_incr:N \l__cfflatex_rsc_contact_count_int
        \tl_set:Ne \l__cfflatex_rsc_symbol_tl
          {
            \prg_replicate:nn { \l__cfflatex_rsc_contact_count_int }
              { \exp_not:N \ast }
          }
        \__cfflatex_rsc_add_footnote:N \l__cfflatex_rsc_contacts_seq
      }
    \tl_put_right:NV \l__cfflatex_rsc_contact_marks_tl
      \l__cfflatex_rsc_symbol_tl
  }
% Notes are marked \ddag, \S, \P, \ddag\ddag, \S\S, and so on.
\cs_new_protected:Npn \__cfflatex_rsc_note:
  {
    \prop_get:NVNF \l__cfflatex_rsc_symbols_prop \l__cfflatex_rsc_text_tl
      \l__cfflatex_rsc_symbol_tl
      {
        \int_incr:N \l__cfflatex_rsc_note_count_int
        \tl_set:Ne \l__cfflatex_rsc_symbol_tl
          {
            \prg_replicate:nn
              {
                \int_div_truncate:nn
                  { \l__cfflatex_rsc_note_count_int - 1 } { 3 } + 1
              }
              {
                \int_case:nn
                  { \int_mod:nn { \l__cfflatex_rsc_note_count_int - 1 } { 3 } }
                  {
                    { 0 } { \exp_not:N \ddag }
                    { 1 } { \exp_not:N \S }
                    { 2 } { \exp_not:N \P }
                  }
              }
          }
        \__cfflatex_rsc_add_footnote:N \l__cfflatex_rsc_notes_seq
      }
    \tl_put_right:NV \l__cfflatex_rsc_note_marks_tl \l__cfflatex_rsc_symbol_tl
  }
\cs_new_protected:Npn \__cfflatex_rsc_add_footnote:N #1
  {
    \prop_put:NVV \l__cfflatex_rsc_symbols_prop \l__cfflatex_rsc_text_tl
      \l__cfflatex_rsc_symbol_tl
    \seq_put_right:Ne #1
      {
        { \exp_not:V \l__cfflatex_rsc_symbol_tl }
        { \exp_not:V \l__cfflatex_rsc_text_tl }
      }
  }

\cs_new_protected:Npn \__cfflatex_rsc_author:nn #1#2
  { \seq_put_right:Nn \l__cfflatex_rsc_authors_seq { {#2} {#1} } }
\cs_new_protected:Npn \__cfflatex_rsc_affiliation:nn #1#2
  {
    \int_compare:nNnTF { \cffaffiliationcount } > { 1 }
      { \seq_put_right:Nn \l__cfflatex_rsc_affiliations_seq { {#1} {#2} } }
      { \seq_put_right:Nn \l__cfflatex_rsc_affiliations_seq { { } {#2} } }
  }

% Like the template: a comma after every name but the last when there are more
% than two, and "and" before the last.
\cs_new_protected:Npn \__cfflatex_rsc_end:
  {
    \tl_clear:N \l__cfflatex_rsc_authors_tl
    \seq_map_indexed_inline:Nn \l__cfflatex_rsc_authors_seq
      { \__cfflatex_rsc_put_author:nnn {##1} ##2 }
    \tl_clear:N \l__cfflatex_rsc_footnotes_tl
    \seq_map_inline:Nn \l__cfflatex_rsc_contacts_seq
      { \__cfflatex_rsc_put_footnote:nn ##1 }
    \seq_map_inline:Nn \l__cfflatex_rsc_affiliations_seq
      { \__cfflatex_rsc_put_footnote:nn ##1 }
    \seq_map_inline:Nn \l__cfflatex_rsc_notes_seq
      { \__cfflatex_rsc_put_footnote:nn ##1 }
    \exp_args:Ne \cffemit
      {
        \exp_not:N \newcommand \exp_not:N \rscauthors
          { \exp_not:V \l__cfflatex_rsc_authors_tl }
      }
    \exp_args:Ne \cffemit
      {
        \exp_not:N \newcommand \exp_not:N \rscfootnotes
          { \exp_not:V \l__cfflatex_rsc_footnotes_tl }
      }
  }
\cs_new_protected:Npn \__cfflatex_rsc_put_author:nnn #1#2#3
  {
    \int_compare:nNnT {#1} > { 1 }
      {
        \int_compare:nNnTF {#1} = { \seq_count:N \l__cfflatex_rsc_authors_seq }
          { \tl_put_right:Nn \l__cfflatex_rsc_authors_tl { ~and~ } }
          { \tl_put_right:Nn \l__cfflatex_rsc_authors_tl { ~ } }
      }
    \tl_put_right:Nn \l__cfflatex_rsc_authors_tl {#2}
    \bool_lazy_and:nnT
      {
        \int_compare_p:nNn {#1}
          < { \seq_count:N \l__cfflatex_rsc_authors_seq }
      }
      {
        \int_compare_p:nNn { \seq_count:N \l__cfflatex_rsc_authors_seq }
          > { 2 }
      }
      { \tl_put_right:Nn \l__cfflatex_rsc_authors_tl { , } }
    \tl_if_empty:nF {#3}
      {
        \tl_put_right:Nn \l__cfflatex_rsc_authors_tl
          { \textit { $ ^ {#3} $ } }
      }
  }
\cs_new_protected:Npn \__cfflatex_rsc_put_footnote:nn #1#2
  {
    \tl_if_empty:nTF {#1}
      {
        \tl_put_right:Nn \l__cfflatex_rsc_footnotes_tl
          { \footnotetext { \textit {#2} } }
      }
      {
        \tl_put_right:Nn \l__cfflatex_rsc_footnotes_tl
          { \footnotetext { \textit { $ ^ {#1} $ \nobreakspace #2 } } }
      }
  }

\cffdeclareauthorstyle { rsc }
  {
    contact = { Corresponding~author.~E-mail:~#1 { email } },
    separator = { },
    begin = { \__cfflatex_rsc_begin: },
    prepare-author = { \__cfflatex_rsc_prepare:n {#1} },
    author-code = { \__cfflatex_rsc_author:nn {#1} {#2} },
    affiliation-code = { \__cfflatex_rsc_affiliation:nn {#1} {#2} },
    end = { \__cfflatex_rsc_end: },
    check-fields = { title, authors, abstract },
    check-region =
      {
        hooks = { env/@twocolumnfalse/begin } { env/@twocolumnfalse/end },
        document,
      },
  }

\ExplSyntaxOff
\endinput