\def\ltlabtbldate{2025-05-10}
\def\ltlabtblversion{0.85s}
\ProvidesExplPackage {table-header-scope} {\ltlabtbldate} {\ltlabtblversion}
  {Code related to the tagging of table headers}

% See the discussion at https://github.com/latex3/tagging-project/discussions/930

% these hooks aren't called?
%\hook_gput_code:nnn { cmd / after / __tbl_set_header_rows: } { latex-lab-testphase-table } { \__tbl_set_td_headers: }
%\AddToHook{ cmd / after / __tbl_set_header_rows: } { \__tbl_set_td_headers: }
% this doesn't work?
%\apptocmd{\__tbl_set_header_rows:}{\__tbl_set_td_headers:}{}{\fail}
% do it the old fashioned way
\tex_let:D \__tbl__old_set_header_rows: = \__tbl_set_header_rows:
\cs_set_protected:Npn \__tbl_set_header_rows:
  {
    \__tbl__old_set_header_rows:
    \__tbl_set_table_header_scope:
  }

\cs_new:Npn \__tbl_set_table_header_scope:
  { \seq_map_function:NN \g__tbl_struct_cells_seq \__tbl_set_row_header_scope:n }

\cs_new:Npn \__tbl_set_row_header_scope:n #1
  { \clist_map_function:nN { #1 } \__tbl_set_td_header_scope:n }

\cs_new:Npn \__tbl_set_td_header_scope:n #1
  {
    \int_compare:nNnT { #1 } > { 0 }
      {
        \prop_if_exist:cT { g__tag_struct_#1_prop }
          {
            \prop_get:cnNT { g__tag_struct_#1_prop } { C } \l__tbl_tmpa_tl
              {
                \tl_clear:N \l_tmpa_tl
                \str_set:Ne \l__tbl_tmpa_str { \l__tbl_tmpa_tl }
                \str_if_in:NnTF \l__tbl_tmpa_str { /TH-both }
                  { \tl_set:Nn \l_tmpa_tl { Both } }
                  {
                    \str_if_in:NnTF \l__tbl_tmpa_str { /TH-row }
                      { \tl_set:Nn \l_tmpa_tl { Row } }
                      {
                        \str_if_in:NnT \l__tbl_tmpa_str { /TH-col }
                          { \tl_set:Nn \l_tmpa_tl { Column } }
                      }
                  }
                \tl_if_empty:NF \l_tmpa_tl
                  {
                    \__tag_struct_prop_gput:nne { #1 } { A }
                      { <</O/Table/Scope/\l_tmpa_tl>> }
                  }
              }
          }
      }
  }