% Source-script numbers and generated suffixes shared by bibliography adapters.
% Part of latexbangla, LPPL 1.3c or later; copyright 2026 Adib Hasan.

% Explicit English environments suspend automatic switching. Select a script
% font only for native runs, leaving surrounding Latin text in its own font.
\cs_new_protected:Npn \__latexbangla_bibliography_native_text:n #1
  {\group_begin:\use:c {\g__latexbangla_language_tl font}#1\group_end:}
\cs_new_protected:Npn \__latexbangla_bibliography_select_fonts:N #1
  {
    \regex_replace_all:nnN {[\x{0980}-\x{09FF}]+}
      {\c{__latexbangla_bibliography_native_text:n}\cB\{\0\cE\}} #1
  }
\cs_new_protected:Npn \__latexbangla_bibliography_normalize:N #1
  {
    \int_step_inline:nnn {0}{9}
      {\tl_replace_all:Nee #1
        {\char_generate:nn {"09E6+##1}{12}} {\int_to_arabic:n {##1}}}
  }
\cs_generate_variant:Nn \tl_replace_all:Nnn {Nee}
\cs_generate_variant:Nn \regex_match:nnTF {nVTF}
\cs_generate_variant:Nn \regex_replace_all:nnN {eeN}

% Bijective lettering also handles suffixes beyond one alphabet cycle.
\cs_new:Npn \__latexbangla_bibliography_native_suffix:n #1
  {
    \int_compare:nNnT {#1}>{\clist_count:N\c__latexbangla_alphabet_clist}
      {\__latexbangla_bibliography_native_suffix:n
        {\int_div_truncate:nn{#1-1}{\clist_count:N\c__latexbangla_alphabet_clist}}}
    \clist_item:Nn \c__latexbangla_alphabet_clist
      {\int_mod:nn{#1-1}{\clist_count:N\c__latexbangla_alphabet_clist}+1}
  }
\cs_new:Npn \__latexbangla_bibliography_english_ordinal:n #1
  {
    \int_compare:nNnTF {\int_mod:nn{#1}{100}} > {10}
      {\int_compare:nNnTF {\int_mod:nn{#1}{100}} < {14}
        {th}{\__latexbangla_bibliography_english_ordinal_last:n {#1}}}
      {\__latexbangla_bibliography_english_ordinal_last:n {#1}}
  }
\cs_new:Npn \__latexbangla_bibliography_english_ordinal_last:n #1
  {\int_case:nnF {\int_mod:nn{#1}{10}} {{1}{st}{2}{nd}{3}{rd}} {th}}
% Arguments: native language, original field, numeric edition value.
\cs_new_protected:Npn \__latexbangla_bibliography_ordinal_suffix:nnn #1#2#3
  {
    \regex_match:nnTF {[০-৯]} {#2}
      {\__latexbangla_bibliography_native_text:n
        {\int_case:nnF {#3}
          {{1}{ম}{2}{য়}{3}{য়}
           {4}{\str_if_eq:eeTF {#1}{assamese}{ৰ্থ}{র্থ}}
           {5}{ম}{6}{ষ্ঠ}{7}{ম}{8}{ম}{9}{ম}{10}{ম}} {তম}}}
      {\__latexbangla_bibliography_english_ordinal:n {#3}}
  }
\cs_generate_variant:Nn \__latexbangla_bibliography_ordinal_suffix:nnn {nVn}
\endinput