%D \module
%D   [       file=strc-pag,
%D        version=2008.10.20,
%D          title=\CONTEXT\ Structure Macros,
%D       subtitle=Pagenumbering,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright=PRAGMA-ADE / Hans Hagen]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

\writestatus{loading}{ConTeXt Structure Macros / Pagenumbering}

\registerctxluafile{strc-pag}{1.001}

\unprotect

% Hacks:

\let\preparepageprefix\gobbleoneargument

% Allocation:

\countdef\realpageno  = 0  \realpageno  = 1
\countdef\userpageno  = 1  \userpageno  = 1
\countdef\subpageno   = 2  \subpageno   = 0 % !!
\countdef\arrangeno   = 3  \arrangeno   = 0 % !!
\countdef\pagenoshift = 4  \pagenoshift = 0 % !!

\let\pageno\userpageno

\def\realfolio{\the\realpageno}
\def\userfolio{\the\userpageno}
\def\subfolio {\the\subpageno }

\newtoks\everyinitializepagecounters

\def\initializepagecounters{\the\everyinitializepagecounters}

\appendtoks
  \initializepagecounters
\to \everyjob

% Page numbers are kind of independent of each other and therefore they
% all get their own counter. After all, it's easier to combine them in
% a pseudo counterset than to deal with a complex set itself.

% \definestructureprefixset   [mine][section-1,section-2]
% \definestructureseparatorset[mine][:]
%
% \setupuserpagenumber
%   [way=bypart,
%    prefix=yes,
%    prefixset=mine,
%    prefixseparatorset=mine]

% \definestructureconversionset[frontpart:pagenumber][][romannumerals]
% \definestructureconversionset[bodypart:pagenumber] [][numbers]
%
% \setupuserpagenumber[way=byblock]
% \setupuserpagenumber[way=bychapter]
% \setupuserpagenumber[numberconversionset=pagenumber]
%
% \starttext
%     \startfrontmatter
%         \completecontent[criterium=all]
%         \chapter{tufte} \section{one} \input tufte \page \section{two} \input tufte \page
%         \chapter{tufte} \section{one} \input tufte \page \section{two} \input tufte \page
%     \stopfrontmatter
%     \startbodymatter
%         \chapter{knuth} \section{one} \input knuth \page \section{two} \input knuth \page \section{three} \input knuth \page
%         \chapter{knuth} \section{one} \input knuth \page \section{two} \input knuth \page \section{three} \input knuth \page
%     \stopbodymatter
% \stoptext


\definestructurecounter[\s!realpage][\c!prefix=\v!no,\c!start=1,\c!prefixsegments=,\s!counter=realpageno]
\definestructurecounter[\s!userpage][\c!prefix=\v!no,\c!start=1,\c!prefixsegments=,\s!counter=userpageno]
\definestructurecounter[\s!subpage] [\c!prefix=\v!no,\c!start=1,\c!prefixsegments=,\s!counter=subpageno]

\newtoks\everysetuprealpagenumber % todo: set state: none, start, stop, reset
\newtoks\everysetupuserpagenumber % todo: set state: none, start, stop, reset
\newtoks\everysetupsubpagenumber  % todo: set state: none, start, stop, reset

\unexpanded\def\setuprealpagenumber{\dosingleargument\dosetuprealpagenumber}
\unexpanded\def\setupuserpagenumber{\dosingleargument\dosetupuserpagenumber}
\unexpanded\def\setupsubpagenumber {\dosingleargument\dosetupsubpagenumber}

\def\dosavepagenumberstate#1{\edef\oldpagenumberstate{\structurecounterparameter#1\c!state}}

\def\dosetuprealpagenumber[#1]{\dosavepagenumberstate\s!realpage\dosetupstructurecounter[\s!realpage][#1]\the\everysetuprealpagenumber}
\def\dosetupuserpagenumber[#1]{\dosavepagenumberstate\s!userpage\dosetupstructurecounter[\s!userpage][#1]\the\everysetupuserpagenumber}
\def\dosetupsubpagenumber [#1]{\dosavepagenumberstate\s!subpage \dosetupstructurecounter[\s!subpage ][#1]\the\everysetupsubpagenumber }

\def\resetrealpagenumber {} % not permitted
\def\resetuserpagenumber {\resetstructurecounter[\s!userpage]}
\def\resetsubpagenumber  {\resetstructurecounter[\s!subpage]}

\appendtoks
    \setstructurecounter[\s!realpage]\realpageno
    \setstructurecounter[\s!userpage]\userpageno
    \setstructurecounter[\s!subpage] \subpageno
\to \everyinitializepagecounters

\let\setuppagenumber\setupuserpagenumber
\let\resetpagenumber\resetuserpagenumber

\def\savecurrentpagestate % \normalexpanded?
  {\ctxlua{structure.pages.save({
        prefix        = "\structurecounterparameter\s!userpage\c!prefix",
        separatorset  = "\structurecounterparameter\s!userpage\c!prefixseparatorset",
        conversion    = "\structurecounterparameter\s!userpage\c!prefixconversion",
        conversionset = "\structurecounterparameter\s!userpage\c!prefixconversionset",
        set           = "\structurecounterparameter\s!userpage\c!prefixset",
        segments      = "\structurecounterparameter\s!userpage\c!prefixsegments",
        connector     = \!!bs\structurecounterparameter\s!userpage\c!prefixconnector\!!es,
    },{
        conversion    = "\structurecounterparameter\s!userpage\c!numberconversion",
        conversionset = "\structurecounterparameter\s!userpage\c!numberconversionset",
        starter       = \!!bs\structurecounterparameter\s!userpage\c!numberstarter\!!es,
        stopper       = \!!bs\structurecounterparameter\s!userpage\c!numberstopper\!!es,
    }
   )}}

\prependtoks
    \savecurrentpagestate
\to \everyshipout

\def\pushpagestate{\setxvalue{\??nm:\s!userpage:\c!state}{\structurecounterparameter\s!userpage\c!state}}
\def\poppagestate {\normalexpanded{\noexpand\setuppagenumber[\c!state=\getvalue{\??nm:\s!userpage:\c!state}]}}

\setuppagenumber
  [\c!way=\v!by\v!text,
   \c!prefix=\v!no,
   \c!prefixset=\v!part,
   \c!prefixconnector=\endash,
   \c!state=\v!start]

\setupsubpagenumber
  [\c!way=\v!by\v!part,
   \c!state=\v!stop]

% Counters

% \def\firstpage    {1} \def\prevpage    {1} \def\nextpage    {1} \def\lastpage    {1}
% \def\firstuserpage{1} \def\prevuserpage{1} \def\nextuserpage{1} \def\lastuserpage{1}
% \def\firstsubpage {1} \def\prevsubpage {1} \def\nextsubpage {1} \def\lastsubpage {1}

% \def\firstrealpage{\firststructurecounter[\s!realpage]}
% \def\prevrealpage {\prevstructurecounter [\s!realpage]}
% \def\nextrealpage {\nextstructurecounter [\s!realpage]}
% \def\lastrealpage {\laststructurecounter [\s!realpage]}

% \let\firstpage\firstrealpage
% \let\prevpage \prevrealpage
% \let\nextpage \nextrealpage
% \let\lastpage \lastrealpage

\def\firstrealpagenumber{\convertedstructurecounter[\s!realpage][\c!type=\v!first]}
\def\firstuserpagenumber{\convertedstructurecounter[\s!userpage][\c!type=\v!first]}
\def\firstsubpagenumber {\convertedstructurecounter[\s!subpage ][\c!type=\v!first]}

\def\lastrealpagenumber {\convertedstructurecounter[\s!realpage][\c!type=\v!last]}
\def\lastuserpagenumber {\convertedstructurecounter[\s!userpage][\c!type=\v!last]}
\def\lastsubpagenumber  {\convertedstructurecounter[\s!subpage ][\c!type=\v!last]}

\def\prevrealpagenumber {\convertedstructurecounter[\s!realpage][\c!type=\v!previous]}
\def\prevuserpagenumber {\convertedstructurecounter[\s!userpage][\c!type=\v!previous]}
\def\prevsubpagenumber  {\convertedstructurecounter[\s!subpage ][\c!type=\v!previous]}

\def\nextrealpagenumber {\convertedstructurecounter[\s!realpage][\c!type=\v!next]}
\def\nextuserpagenumber {\convertedstructurecounter[\s!userpage][\c!type=\v!next]}
\def\nextsubpagenumber  {\convertedstructurecounter[\s!subpage ][\c!type=\v!next]}

\def\firstrealpage{\firststructurecounter[\s!realpage]}
\def\firstuserpage{\firststructurecounter[\s!userpage]}
\def\firstsubpage {\firststructurecounter[\s!subpage ]}

\def\prevrealpage {\prevstructurecounter [\s!realpage]}
\def\prevuserpage {\prevstructurecounter [\s!userpage]}
\def\prevsubpage  {\prevstructurecounter [\s!subpage ]}

\def\nextrealpage {\nextstructurecounter [\s!realpage]}
\def\nextuserpage {\nextstructurecounter [\s!userpage]}
\def\nextsubpage  {\nextstructurecounter [\s!subpage ]}

\def\lastrealpage {\laststructurecounter [\s!realpage]}
\def\lastuserpage {\laststructurecounter [\s!userpage]}
\def\lastsubpage  {\laststructurecounter [\s!subpage ]}

\let\firstpage\firstrealpage
\let\prevpage \prevrealpage
\let\nextpage \nextrealpage
\let\lastpage \lastrealpage

% Compatibility counters:

\def\nofrealpages {\lastrealpage} \def\totalnumberofpages{\lastrealpage}
\def\nofuserpages {\lastuserpage} \def\lastpagenumber    {\lastuserpage}
\def\nofsubpages  {\lastsubpage }

% Renderers:

\def\pagenumber         {\rawstructurecounter[\s!userpage]}
\def\prefixedpagenumber {\directconvertedstructurecounter\s!userpage\empty} % \userpagenumber

\def\realpagenumber     {\directconvertedstructurecounter\s!realpage\empty}
\def\userpagenumber     {\directconvertedstructurecounter\s!userpage\empty}
\def\subpagenumber      {\directconvertedstructurecounter\s!subpage \empty}

\def\firstrealpagenumber{\directconvertedstructurecounter\s!realpage\v!first}
\def\firstuserpagenumber{\directconvertedstructurecounter\s!userpage\v!first}
\def\firstsubpagenumber {\directconvertedstructurecounter\s!subpage \v!first}

\def\lastrealpagenumber {\directconvertedstructurecounter\s!realpage\v!last}
\def\lastuserpagenumber {\directconvertedstructurecounter\s!userpage\v!last}
\def\lastsubpagenumber  {\directconvertedstructurecounter\s!subpage \v!last}

\def\prevrealpagenumber {\directconvertedstructurecounter\s!realpage\v!previous}
\def\prevuserpagenumber {\directconvertedstructurecounter\s!userpage\v!previous}
\def\prevsubpagenumber  {\directconvertedstructurecounter\s!subpage \v!previous}

\def\nextrealpagenumber {\directconvertedstructurecounter\s!realpage\v!next}
\def\nextuserpagenumber {\directconvertedstructurecounter\s!userpage\v!next}
\def\nextsubpagenumber  {\directconvertedstructurecounter\s!subpage \v!next}

\appendtoks
    \decrementstructurecounter[\s!realpage]%
    \decrementstructurecounter[\s!userpage]%
    \decrementstructurecounter[\s!subpage]%
\to\everygoodbye

% Equivalents (compatibility):
%
% todo: maybe leave lastpage etc lua calls

\def\realpage{\the\realpageno}
\def\userpage{\the\userpageno}
\def\subpage {\the\subpageno}

% Hooks:

\def\currentpage{\the\realpageno}% rather useless

\appendtoks
    \ifnum\realpageno>\lastpage \globallet\lastpage\lastrealpage \fi
\to \everyinitializepagecounters

% States:

\newif\ifrightpage    \rightpagetrue
\newif\ifdoublesided
\newif\ifsinglesided

% Realpage and subpage numbers:

\def\setnextrealpageno{\global\realpageno\incrementedstructurecounter[\s!realpage]\relax}
\def\setnextsubpageno {\global\subpageno \incrementedstructurecounter[\s!subpage ]\relax}

% Page numbers: (can move to lua)

\def\dodecrementpagenumber {\global\userpageno\decrementedstructurecounter[\s!userpage]\relax}
\def\doincrementpagenumber {\global\userpageno\incrementedstructurecounter[\s!userpage]\relax}

\def\decrementsubpagenumber{\global\subpageno \decrementedstructurecounter[\s!subpage ]\relax}
\def\incrementsubpagenumber{\global\subpageno \incrementedstructurecounter[\s!subpage ]\relax}

\def\dosynchronizepagenumber{\global\let\@@pnstate\v!start}

\def\decrementpagenumber{\csname\??pn-\structurecounterparameter\s!userpage\c!state\endcsname}
\def\incrementpagenumber{\csname\??pn+\structurecounterparameter\s!userpage\c!state\endcsname}

\letvalue{\??pn-\v!start}\dodecrementpagenumber
\letvalue{\??pn-\v!none }\dodecrementpagenumber
\letvalue{\??pn-\v!empty}\dodecrementpagenumber

\letvalue{\??pn+\v!start}\doincrementpagenumber
\letvalue{\??pn+\v!none }\doincrementpagenumber
\setvalue{\??pn+\v!empty}{\doincrementpagenumber\dosynchronizepagenumber}
\letvalue{\??pn+\v!keep }\dosynchronizepagenumber

% Control:

\def\getpagestatus % hierboven gebruiken
  {\ifdoublesided
     \global\rightpagetrue
     % todo: \global\rightpagetrue or \global\rightpagefalse
   \else
     \global\rightpagetrue
   \fi}

% Setup general page numbering

\newtoks\everysetuppagenumbering

\unexpanded\def\setuppagenumbering
  {\dosingleempty\dosetuppagenumbering}

\def\dosetuppagenumbering[#1]%
  {\getparameters[\??nm][#1]\the\everysetuppagenumbering}

\appendtoks
   \singlesidedfalse
   \doublesidedfalse
   \normalexpanded{\noexpand\processallactionsinset[\@@nmalternative]}
     [ \v!singlesided=>\singlesidedtrue,
       \v!doublesided=>\doublesidedtrue]%
   \ifx\trackingmarginnotestrue\undefined\else
     \ifdoublesided
       \trackingmarginnotestrue
     \else
       \trackingmarginnotesfalse
     \fi
   \fi
   \dosetpagenumberlocation
\to \everysetuppagenumbering

\appendtoks
   \ifdefined \recalculatebackgrounds \recalculatebackgrounds \fi
\to \everysetuppagenumbering

\def\flushfinallayoutpage
  {\doifsomething\@@nmpage{\doifnot\@@nmpage\v!no{\page[\@@nmpage]}}}

% The numbered location handler is there because we need to be downward
% compatible. So, in fact there can be multiple handlers active at the
% same time, but only the current one does something.
%
% thsi code might move to page-txt

\newcount\currentpagenumberlocation

\def\dosetpagenumberlocation
  {\advance\currentpagenumberlocation\plusone
   \ifx\@@nmlocation\empty \else
     \let\@@pagenumbervlocation\v!footer
     \let\@@pagenumberhlocation\v!text
     \let\@@pagenumberxlocation\c!middletext
     \normalexpanded{\noexpand\processallactionsinset[\@@nmlocation]}
       [    \v!header=>\let\@@pagenumbervlocation\v!header,
            \v!footer=>\let\@@pagenumbervlocation\v!footer,
            \v!middle=>\let\@@pagenumberhlocation\v!text  \let\@@pagenumberxlocation\c!middletext,
              \v!left=>\let\@@pagenumberhlocation\v!text  \let\@@pagenumberxlocation\c!lefttext,
             \v!right=>\let\@@pagenumberhlocation\v!text  \let\@@pagenumberxlocation\c!righttext,
            \v!inleft=>\let\@@pagenumberhlocation\v!margin\let\@@pagenumberxlocation\c!lefttext,
           \v!inright=>\let\@@pagenumberhlocation\v!margin\let\@@pagenumberxlocation\c!righttext,
          \v!inmargin=>\let\@@pagenumberhlocation\v!margin\def\@@pagenumberxlocation{\ifdoublesided\c!margintext\else\c!righttext\fi},
            \v!margin=>\let\@@pagenumberhlocation\v!margin\def\@@pagenumberxlocation{\ifdoublesided\c!margintext\else\c!righttext\fi},
          \v!atmargin=>\let\@@pagenumberhlocation\v!text  \let\@@pagenumberxlocation\c!marginedgetext,
        \v!marginedge=>\let\@@pagenumberhlocation\v!text  \let\@@pagenumberxlocation\c!marginedgetext]%
     \normalexpanded{\noexpand\setspecificlayouttext
        {\@@pagenumbervlocation}{\@@pagenumberhlocation}{\@@pagenumberxlocation}%
        {\noexpand\doplacepagenumberatlocation{\number\currentpagenumberlocation}}}%
   \fi}

\def\setspecificlayouttext#1#2#3#4{\setvalue{\??tk#1#2#3}{#4}} % weird place

\appendtoks
    \dosetpagenumberlocation
\to \everyinitializepagecounters

\def\doplacepagenumberatlocation#1%
  {\ifnum#1=\currentpagenumberlocation\relax\expandafter\placelocationpagenumber\fi}

% Rendering:

\unexpanded\def\placelocationpagenumber
  {\ifnum\userpagenumberstate=\plustwo
     \ifnum\overallpagenumberstate=\plusone
        \doif\@@nmstrut\v!yes\strut
        \@@nmcommand{\doattributes\??nm\c!style\c!color{\@@nmleft\labeltexts\v!pagenumber{\prefixedpagenumber}\@@nmright}}%
     \fi
   \fi}

\unexpanded\def\completepagenumber
  {\ifnum\userpagenumberstate=\plustwo
     \ifnum\overallpagenumberstate=\plusone
        \@@nmleft\labeltexts\v!pagenumber\prefixedpagenumber\@@nmright
     \fi
   \fi}

\unexpanded\def\placepagenumber
  {\ifnum\userpagenumberstate=\plustwo
     \ifnum\overallpagenumberstate=\plusone
        \labeltexts\v!pagenumber\pagenumber
     \fi
   \fi}

\unexpanded\def\referencepagenumber[#1]%
  {\doifelsenothing{#1}{?}{}}

% The numbered location handler is there because we need to be downward
% compatible. So, in fact there can be multiple handlers active at the
% same time, but only the current one does something.

\chardef\realpagenumberstate   =2 % counter state : 0=stop, 1=start, 2=start and visible
\chardef\userpagenumberstate   =2 % counter state : 0=stop, 1=start, 2=start and visible
\chardef\subpagenumberstate    =2 % counter state : 0=stop, 1=start, 2=start and visible
\chardef\overallpagenumberstate=1 % general number: 0=invisible, 1=visible

\def\checkpagenumberstatechange#1#2%
  {\edef\newpagenumberstate{\structurecounterparameter#1\c!state}%
   \ifx\newpagenumberstate\oldpagenumberstate \else
     \doifelse\newpagenumberstate\v!start
         {\chardef#2\plustwo}%
         {\chardef#2\zerocount}%
   \fi}

\appendtoks % todo: set state: none, start, stop, reset
    \checkpagenumberstatechange\s!realpage\realpagenumberstate
\to \everysetuprealpagenumber

\appendtoks % todo: set state: none, start, stop, reset
    \checkpagenumberstatechange\s!userpage\userpagenumberstate
\to \everysetupuserpagenumber

\appendtoks % todo: set state: none, start, stop, reset
    \checkpagenumberstatechange\s!subpage\subpagenumberstate
\to \everysetupsubpagenumber

\appendtoks % todo: set state: none, start, stop, reset
    \doifelse\@@nmstate\v!start
        {\chardef\overallpagenumberstate\plusone}%
        {\chardef\overallpagenumberstate\zerocount}%
\to \everysetuppagenumbering

% Done

% \c!way=\v!by\v!part
% \c!text=
% \v!chapter\v!number=\v!no
% \v!part\v!number=\v!yes
% \c!numberseparator=--
% \c!conversion=\v!numbers

\setuppagenumbering
  [\c!alternative=\v!singlesided,
   \c!location={\v!header,\v!middle},
   \c!width=, % in geval van \v!marginedge
   \c!left=,
   \c!right=,
   \c!page=\v!last,
   \c!textseparator=\tfskip,
   \c!state=\v!start,
   \c!command=,
   \c!strut=\v!yes,
   \c!style=, % empty, otherwise conflict
   \c!color=]

% just for downward compatbility

\appendtoks
    \edef\askeduserpagenumber{\structurecounterparameter\s!userpage\c!number}%
    \ifx\askeduserpagenumber\empty \else
      \normalexpanded{\noexpand\setuppagenumber[\c!start=\structurecounterparameter\s!userpage\c!number,\c!number=]}%
      \userpageno\rawstructurecounter[\s!userpage]%
    \fi
\to \everysetupuserpagenumber % todo: set state: none, start, stop, reset

\appendtoks
    \edef\askedsubpagenumber{\structurecounterparameter\s!subpage\c!number}%
    \ifx\askedsubpagenumber\empty \else
      \normalexpanded{\noexpand\setupsubpagenumber[\c!start=\structurecounterparameter\s!subpage\c!number,\c!number=]}%
      \subpageno\rawstructurecounter[\s!subpage]%
    \fi
\to \everysetupsubpagenumber % todo: set state: none, start, stop, reset

% \setuplayout[width=300pt,backspace=4cm]
% \setuppagenumbering [alternative=doublesided]
% \setupuserpagenumber[start=2]
% \starttext \dorecurse{20}{\input knuth \par} \stoptext

\def\checkpagenumbershift
  {\userpageno\rawstructurecounter[\s!userpage]\relax
   \ifnum\realpageno=\plusone
     \ifodd\userpageno
     \else
       \global\pagenoshift\plusone
     \fi
   \fi}

\appendtoks % todo: set state: none, start, stop, reset
    % this makes starting at an even page possible
    \checkpagenumbershift
\to \everysetupuserpagenumber

\appendtoks % todo: set state: none, start, stop, reset
    % this makes starting at an even page possible
    \checkpagenumbershift
\to \everysetuppagenumbering

\initializepagecounters

\protect \endinput