%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Module:    ZzTeX Interface to BibTeX
%
% Synopsis:  This module provides the definitions necessary for ZzTeX to
%            interface to BibTeX.
%
% Author:    Paul C. Anagnostopoulos
% Created:   21 July 1992
%
% Copyright 1989--2020 by Paul C. Anagnostopoulos
% under The MIT License (opensource.org/licenses/MIT)
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%                       Bibliography Preparation
%                       ------------ -----------


\def \zbiblioinit {}

\ignore
\setflag \zbiblioing = \false

\def \preparebiblio {%
  \setflag \zbiblioing = \true}

\def \zbibfinal {%
  \if \zbiblioing
    \remark{[Generating auxiliary file for BibTeX.}%
    {\immediate\openout \zwritea = \jobname.aux\relax
     \immediate\write \zwritea
       {\zcomment BibTeX auxiliary file for book `\jobname'.}%
     \processdesign{\biblio}{}%
     \immediate\write \zwritea {\string\bibstyle{\the\bibliostyle}}%
     \immediate\write \zwritea {\string\bibdata{\the\bibliofiles}}%
     \let \zxmodesave = \xrefmode
     \let \xrefmode = \xrefloadauxmode
     \input \jobname.zzc\relax
     \let \xrefmode = \zxmodesave
     \immediate\write \zwritea {\zcomment [end]}%
     \immediate\closeout \zwritea}
    \remark{Auxiliary file complete.]}%
  \fi}

\endignore

%                       Citations
%                       ---------


%~ This citation command produces the key associated with 
%~ the specified tag. The key is usually the bibliography
%~ entry number or the author/year combination.&/
%~ *Note:* Some books do not allow this command to be used.

\def \cite #1{%                                         {tag} %^citation
  \ensurepar
  \if \definedp{\=zB:#1}%
    \zcitetext{#1}{\expandafterthrice\zbibdata \name{\=zB:#1}0}%
  \else
    \zuncite{#1}%
  \fi
  \zxrefcite{\true}{#1}}

%~ This citation command produces the author associated with
%~ the specified tag.

\def \citeauthor #1{%                                   {tag} %^citation
  \ensurepar
  \if \definedp{\=zB:#1}%
    \zcitetext{#1}{\expandafterthrice\zbibdata \name{\=zB:#1}1}%
  \else
    \zuncite{#1}%
  \fi
  \zxrefcite{\true}{#1}}

%~ This citation command produces the year associated with
%~ the specified tag.

\def \citeyear #1{%                                     {tag} %^citation
  \ensurepar
  \if \definedp{\=zB:#1}%
    \zcitetext{#1}{\expandafterthrice\zbibdata \name{\=zB:#1}2}%
  \else
    \zuncite{#1}%
  \fi
  \zxrefcite{\true}{#1}}

\def \nocite #1{%                                       {tag}
  \zxrefcite{\false}{#1}}

\def \zcitetext #1#2{%                                  {tag}{text}
  \if \PDFhyperlinks
    \tagbutton{#1}{#2}%
  \else
    #2%
  \fi}

\def \zxrefcite #1#2{%
  \ifcase \xrefcites
    \relax
  \or
    \xref{cite}{\folio}{}{}{#2}%
  \else
    \customcitexref{#1}{#2}%                            {boolean}{tag}
  \fi}

\def \zbibdata #1\zmark#2\zmark#3#4#5#6{%         folio\zmark xxx\zmark
                                        %         {label}{author}{year}n
  \if \DVIWindoinuse \colorspecial{ifview color push rgb .75 .35 0}\fi
  \ifcase #6 #3\or #4\or #5\fi
  \if \DVIWindoinuse \colorspecial{ifview color pop}\fi
  \if \indexcites \xcite1{#4}\fi}

\def \zuncite #1{%
  \writelog{ZzTeX citation: undefined tag `#1'.}%
  \zxwriteinfo{\false}{undef-tag}{#1}{}%
  \global\increment \zuntagrefs
  \zbibdata -\zmark-\zmark{???}--0}

%                       Bibliography Cross-Reference
%                       ------------ ---------------


% When tags are loaded, define the name \=zB:tag to contain the
% bibliographic info.

\def \xrefbib #1#2#3#4{%                {page}{???}{{label}{author}{year}}{tag}
  \ifnum \xrefmode=\xrefloadtagmode
    \if \definedp{\=zB:#4}\zduptag{#4}\fi
    \withname\gdef{\=zB:#4}{#1\zmark#2\zmark#3}%
  \fi}

% This macro loads the cite cross-reference entries and invokes the
% specified macro for each one.

\def \mapxrefcites #1{%                                         {\macro}
  {\let \zmapcitemacro = #1\relax
  \zxloadcomp{\xrefloadcitemode}}}

\def \xrefcite #1#2#3#4{%                                       {page}{}{}{tag}
  \ifnum \xrefmode=\xrefloadcitemode
    \zmapcitemacro{#1}{#4}%
  \fi}

%                       Biblio Block
%                       ------ -----


\defineblock{\biblio}{\endbiblio}{\false}{}

%~block biblio
% \bibliofiles = {file,...}             % List of biblio database files. 
% \bibliostyle = {name}                 % Name of biblio style.
% \setflag \citeself = boolean          % If true, \bibitem cites itself.
%~end

\definetoks{\bibliofiles}
\definetoks{\bibliostyle}

\definecount{\zbiblionum}{0}


\def \biblio {%
  \blockcantbein{\biblio}{\biblio}%
  \blockmustbein{\biblio}{\list}%
  \beginblockscope{biblio}%
  \global\increment \bibliodepth
  \setflag \citeself = \false                   %~default soft
  \processdesign{\biblio}{}%
  \global\increment \biblionumber
  \def \begin ##1##2{}%
  \def \end ##1{}%
  \let \bibitem = \zbibitem
  \let \newblock = \relax
  \let \em = \it
  \zbiblionum = 0\relax}

\def \endbiblio {%
  \endgraf
  \fakepar                                      % In case biblio is empty.
  \global\decrement \bibliodepth
  \endblockscope{biblio}}

%                       Bibliography Item
%                       ------------ ----


\definetoks{\zbibtoksa}
\definetoks{\zbibtoksb}
\definetoks{\zbibtoksc}
\definetoks{\bibitemtag}                        % Tag of current \bibitem.


% This supports items of the form `\bibitem[label][author][year]{tag}'.

\def \zbibitem {%
  \futurelet\znext \zbibitema}

\def \zbibitema {%
  \ifx \znext[%
    \let \znext = \zbibitemb
  \else
    \increment \zbiblionum
    % Expand \number\zbiblionum by hand.
    \edef \znext {\noexpand\zbibitemb[\number\zbiblionum]}%
  \fi
  \znext}

\def \zbibitemb[#1]{%                                   [label]
  \zbibtoksa = {#1}%
  \futurelet\znext \zbibitemc}

\def \zbibitemc {%
  \if \tokeqlp{\znext}{[}%
    \let \znext = \zbibitemd
  \else
    \def \znext {\zbibitemd[???]}%
  \fi
  \znext}

\def \zbibitemd[#1]{%                                   [author]
  \zbibtoksb = {#1}%
  \futurelet\znext \zbibiteme}

\def \zbibiteme {%
  \if \tokeqlp{\znext}{[}%
    \let \znext = \zbibitemf
  \else
    \def \znext {\zbibitemf[???]}%
  \fi
  \znext}

\def \zbibitemf[#1]#2{%                                   [year]{tag}
  \zbibtoksc = {#1}%
  \bibitemtag = {#2}%
  \item{\the\zbibtoksa}%
  \if \PDFhyperlinks \PDFmark{T:#2}\fi
  \if \notp{\emptyargp{#2}}%
    \edef \znext{\noexpand\xref{bib}{\noexpand\folio}
                            {???}
                            {{\the\zbibtoksa}{\the\zbibtoksb}{\the\zbibtoksc}}
                            {#2}}%
    \znext
    \if \citeself \nocite{#2}\fi
  \fi
  \if \indexcites
    \edef \znext {\noexpand\xbiblio1{\the\zbibtoksb}}%
    \znext
  \fi
  \ignorespaces}

%                       Bibliography Citation Page List
%                       ------------ -------- ---- ----


\setflag \zcitexrefsloaded = \false


% If this macro is specified as the \endpartext of a bibliography
% list, it will append a list of the citation pages to each entry.

\def \citepagelist #1{%                                 {button?}
  \if \notp{\zcitexrefsloaded}%
    \mapxrefcites{\zbibcitelist}%
    \global\setflag \zcitexrefsloaded = \true
  \fi
  \setflag \zbibfirstpage = \true
  \def \zbibprevpage {}%
  \withname\maplistlf {\=citetag:\the\bibitemtag}
                      {\zbibcitepage{##1}{#1}}}

\def \zbibcitelist #1#2{%                               {page}{tag}
  \if \withname\undefinedp {\=citetag:#2}%
    \withname\setlist {\=citetag:#2}={}%
  \fi
  \withname\appendlf {\=citetag:#2}{#1}}

\def \zbibcitepage #1#2{%                               {page}{button?}
  \stringeql{\zsamepage}{#1}{\zbibprevpage}%
  \if \notp{\zsamepage}%
    \if \notp{\emptydefp{\zbibprevpage}},\space \fi
    \if #2%
      \pagebutton{#1}{#1}%
    \else
      #1%
    \fi
    \def \zbibprevpage {#1}%
  \fi}
