%D \module
%D   [       file=page-lin,
%D        version=2007.11.29,
%D          title=\CONTEXT\ Core Macros,
%D       subtitle=Line Numbering,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

% generic or not ... maybe not bother too much and simplify to mkiv only
% get rid of \mk* (left over from experimental times)
%
% to be redone (was experiment) .. can be hooked into margin code
% reshuffle arguments

\writestatus{loading}{ConTeXt Core Macros / Line Numbering}

\unprotect

% todo: save settings
%
% low level interface
%
% we should use normal counters but then we need to sync settings

% some line
%
% \startlocallinenumbering
% some source code 1\par
% some source code 2\par
% some source code 3\par
% \stoplocallinenumbering
%
% some line

\registerctxluafile{page-lin}{1.001}

\definesystemattribute[linenumber]   [public]
\definesystemattribute[linereference][public]

\appendtoksonce
    \attribute\linenumberattribute\attributeunsetvalue
\to \everyforgetall

\newcount   \linenumber % not used
\newbox     \b_page_lines_scratch
\newcount   \c_page_lines_reference
\newconstant\c_page_lines_nesting

\newconditional\tracelinenumbering % we keep this for old times sake

\installtextracker
  {lines.numbers.show}
  {\settrue \tracelinenumbering}
  {\setfalse\tracelinenumbering}

% id nr shift width leftskip dir

\installcorenamespace{linenumberinginstance}

% tag skipflag s getfield(n,"shift") getfield(n,"width") leftmarginwidth(getlist(n)) getfield(n,"dir"))

\let\makelinenumber\gobblesevenarguments % used at lua end

\newconditional\page_postprocessors_needed_box

\unexpanded\def\page_postprocessors_linenumbers_page   #tag{\page_lines_add_numbers_to_box{#tag}\plusone      \plusone   \zerocount}
\unexpanded\def\page_postprocessors_linenumbers_box    #tag{\page_lines_add_numbers_to_box{#tag}\plusone      \plusone   \zerocount}
\unexpanded\def\page_postprocessors_linenumbers_deepbox#tag{\page_lines_add_numbers_to_box{#tag}\plusone      \plusone   \plusone  }
\unexpanded\def\page_postprocessors_linenumbers_column #tag{\page_lines_add_numbers_to_box{#tag}\currentcolumn\nofcolumns\zerocount}

\def\page_lines_start_define
  {\setxvalue{\??linenumberinginstance\currentlinenumbering}%
     {\clf_registerlinenumbering
        continue {\ifnum\c_page_lines_mode=\zerocount\v!yes\else\v!no\fi}%
        start    \linenumberingparameter\c!start
        step     \linenumberingparameter\c!step
        method   {\linenumberingparameter\c!method}%
        tag      {\currentlinenumbering}%
     }}

\def\page_lines_start_update
  {\clf_setuplinenumbering
     \csname\??linenumberinginstance\currentlinenumbering\endcsname
     {%
        continue {\ifnum\c_page_lines_mode=\zerocount\v!yes\else\v!no\fi}%
     }%
   \relax}

\def\page_lines_setup
  {\ifcsname \??linenumberinginstance\currentlinenumbering\endcsname
     \clf_setuplinenumbering
       \csname\??linenumberinginstance\currentlinenumbering\endcsname
       {%
            continue {\ifnum\c_page_lines_mode=\zerocount\v!yes\else\v!no\fi}%
            start    \linenumberingparameter\c!start
            step     \linenumberingparameter\c!step
            method   {\linenumberingparameter\c!method}%
            tag      {\currentlinenumbering}%
       }%
     \relax
   \fi}

% we could make this a bit more efficient by putting the end reference
% in the same table as the start one but why make things complex ...

\unexpanded\def\page_lines_some_reference#1#2#3%
  {\dontleavehmode\begingroup
   \global\advance\c_page_lines_reference\plusone
   \attribute\linereferenceattribute\c_page_lines_reference
   #3% todo: #3{#1} as there is no need to pass #1 as part of #3
   % for the moment we use a simple system i.e. no prefixes etc .. todo: store as number
   \c_strc_references_bind_state\zerocount % we don't want the prewordbreak and manage it here
   \normalexpanded{\strc_references_set_named_reference{line}{#2}{conversion=\linenumberingparameter\c!conversion}{\the\c_page_lines_reference}}% kind labels userdata text
   \endgroup}

% \def\page_lines_reference_start#1{\page_lines_some_reference{#1}{lr:b:#1}{}} % reimplemented later
% \def\page_lines_reference_stop #1{\page_lines_some_reference{#1}{lr:e:#1}{}} % reimplemented later

% \def\mklinestartreference#1[#2]{\in{#1}[lr:b:#2]} % not interfaced/ not used
% \def\mklinestopreference #1[#2]{\in{#1}[lr:e:#2]} % not interfaced/ not used

\newif\ifnumberinglines   % will change
\newif\iftypesettinglines % will change

\installcorenamespace{linenumbering}

\installcommandhandler \??linenumbering {linenumbering} \??linenumbering

\setnewconstant\c_page_lines_mode     \plusone  % 0=continue, 1=restart
\setnewconstant\c_page_lines_location \plusone  % 0=middle, 1=left, 2=right, 3=inner, 4=outer, 5=text, 6=begin, 7=end
\setnewconstant\c_page_lines_alignment\plusfive % 0=middle, 1=left, 2=right, 5=auto

\newdimen\d_page_lines_width
\newdimen\d_page_lines_distance

\newevery \beforeeverylinenumbering \relax
\newevery \aftereverylinenumbering  \relax
\newevery \everylinenumber          \relax

\appendtoks
   \page_lines_setup
\to \everysetuplinenumbering

\appendtoks
   \page_lines_start_define
\to \everydefinelinenumbering

\setuplinenumbering
  [\c!conversion=\v!numbers,
   \c!start=1,
   \c!step=1,
   \c!method=\v!first,
   \c!continue=\v!no,
   \c!style=,
   \c!color=,
   \c!width=2\emwidth,
   \c!left=,
   \c!right=,
   \c!command=,
   \c!margin=2.5\emwidth,
   \c!distance=\zeropoint,
   \c!location=\v!default, % depends on direction, columns etc
   \c!align=\v!auto]

\definelinenumbering
  []

% \startlinenumbering[<startvalue>|continue|settings|name]
% \startlinenumbering[name][<startvalue>|continue|settings]

\unexpanded\def\startlinenumbering
  {\dodoubleempty\page_lines_start}

\def\page_lines_start % we stay downward compatible
  {\begingroup
   \ifsecondargument
     \expandafter\page_lines_start_two
   \else\iffirstargument
     \doubleexpandafter\page_lines_start_one
   \else
     \doubleexpandafter\page_lines_start_zero
   \fi\fi}

\def\page_lines_start_zero[#1][#2]%
  {\edef\m_argument{\linenumberingparameter\c!continue}%
   \ifx\m_argument\v!continue
     \c_page_lines_mode\zerocount
   \else
     \c_page_lines_mode\plusone
   \fi
   \page_lines_start_followup}

\def\page_lines_start_one[#1][#2]% [continue|<number>|settings] % historic
  {\edef\m_argument{#1}%
   \ifx\m_argument\v!continue
     \c_page_lines_mode\zerocount
     \let\currentlinenumbering\empty
   \else
     \c_page_lines_mode\plusone
     \ifx\m_argument\v!empty
       \let\currentlinenumbering\empty
     \else
       \doifelseassignment{#1}
         {\let\currentlinenumbering\empty
          \setupcurrentlinenumbering[#1]}
         {\doifelsenumber\m_argument
            {\let\currentlinenumbering\empty
             \letlinenumberingparameter\c!start\m_argument}
            {\let\currentlinenumbering\m_argument}}%
     \fi
     \edef\p_continue{\linenumberingparameter\c!continue}%
     \ifx\p_continue\v!yes
       \c_page_lines_mode\zerocount
     \fi
   \fi
   \page_lines_start_followup}

\def\page_lines_start_two[#1][#2]% [tag][continue|<number>|settings]
  {\edef\currentlinenumbering{#1}%
   \edef\m_argument{#2}%
   \ifx\m_argument\v!continue
     \c_page_lines_mode\zerocount
   \else
     \c_page_lines_mode\plusone
     \ifx\m_argument\v!empty \else
       \doifelseassignment{#2}
         {\setupcurrentlinenumbering[#2]}
         {\doifnumber\m_argument
            {\letlinenumberingparameter\c!start\m_argument}}%
     \fi
     \edef\p_continue{\linenumberingparameter\c!continue}%
     \ifx\p_continue\v!yes
       \c_page_lines_mode\zerocount
     \fi
   \fi
   \page_lines_start_followup}

\newconditional\c_page_lines_auto_narrow

\def\page_lines_start_followup
  {\numberinglinestrue
   \edef\p_location{\linenumberingparameter\c!location}%
   \setfalse\c_page_lines_auto_narrow
   \ifhmode \else
     \ifx\p_location\v!text
       \ifdim\leftskip>\zeropoint \else
         \advance\leftskip\linenumberingparameter\c!margin
         \settrue\c_page_lines_auto_narrow
       \fi
     \else\ifx\p_location\v!begin
       \ifdim\leftskip>\zeropoint \else
         \advance\leftskip\linenumberingparameter\c!margin
         \settrue\c_page_lines_auto_narrow
       \fi
     \else\ifx\p_location\v!end
       \ifdim\leftskip>\zeropoint \else
         \advance\rightskip\linenumberingparameter\c!margin
         \settrue\c_page_lines_auto_narrow
       \fi
     \fi\fi\fi
   \fi
   \the\beforeeverylinenumbering
   \globallet\page_postprocessors_page  \page_postprocessors_linenumbers_page
   \globallet\page_postprocessors_column\page_postprocessors_linenumbers_column
   \global\settrue\page_postprocessors_needed_box % see core-rul.mkiv
   \ifcase\c_page_lines_mode\relax
     \page_lines_start_update % continue
   \or
     \page_lines_start_define % only when assignment
   \fi
   \attribute\linenumberattribute\csname\??linenumberinginstance\currentlinenumbering\endcsname\relax}

\unexpanded\def\stoplinenumbering
  {\attribute\linenumberattribute\attributeunsetvalue
   \the\aftereverylinenumbering
   \ifconditional\c_page_lines_auto_narrow\par\fi
   \endgroup}

% number placement .. will change into (the new) margin code

\newconditional\c_page_lines_fake_number
\newconstant   \b_page_lines_number
\newconstant   \c_page_lines_column
\newconstant   \c_page_lines_last_column
\newdimen      \d_page_lines_line_width
\settrue       \c_page_lines_dir_left_to_right

\installcorenamespace{linenumberinghandler}

\def\page_line_swap_align % can become a helper
  {\ifx\p_align\v!inner     \let\p_align\v!outer     \else
   \ifx\p_align\v!outer     \let\p_align\v!inner     \else
   \ifx\p_align\v!flushleft \let\p_align\v!flushright\else
   \ifx\p_align\v!flushright\let\p_align\v!flushleft \else
   \ifx\p_align\v!left      \let\p_align\v!right     \else
   \ifx\p_align\v!right     \let\p_align\v!left      \fi\fi\fi\fi\fi\fi}

\def\page_lines_add_numbers_to_box#box#column#max#nesting%
  {\bgroup
   \b_page_lines_number     #box\relax
   \c_page_lines_column     #column\relax
   \c_page_lines_last_column#max\relax
   \c_page_lines_nesting    #nesting\relax
   \fullrestoreglobalbodyfont
   \let\makelinenumber\page_lines_make_number % used at lua end
   \setbox\b_page_lines_scratch\vbox
     {\forgetall
      \offinterlineskip
      \clf_linenumbersstageone
        \b_page_lines_number
        \ifcase\c_page_lines_nesting false\else true\fi
      \relax}%
   \clf_linenumbersstagetwo
     \b_page_lines_number
     \b_page_lines_scratch
   \fi
   \egroup}

\let\page_lines_make_number_indeed\relax

% \def\page_lines_rlap{\ifconditional\c_page_lines_dir_left_to_right\expandafter\rlap\else\expandafter\llap\fi}
% \def\page_lines_llap{\ifconditional\c_page_lines_dir_left_to_right\expandafter\llap\else\expandafter\rlap\fi}

\def\page_lines_add_numbers_to_box#box#column#max#nesting%
  {\bgroup
   \b_page_lines_number     #box\relax
   \c_page_lines_column     #column\relax
   \c_page_lines_last_column#max\relax
   \c_page_lines_nesting    #nesting\relax
   \fullrestoreglobalbodyfont
   \let\makelinenumber\page_lines_make_number % used at lua end
   \setbox\b_page_lines_scratch\vbox
     {\forgetall
      \offinterlineskip
      \clf_linenumbersstageone
        \b_page_lines_number
        \ifcase\c_page_lines_nesting false\else true\fi
      \relax}%
   \clf_linenumbersstagetwo
     \b_page_lines_number
     \b_page_lines_scratch
   \relax
   \egroup}

\def\page_lines_make_number#tag#mode#linenumber#shift#width#leftskip#dir% beware, one needs so compensate for this in the \hsize
  {\naturalhbox to \zeropoint \bgroup
   \ifcase#mode\relax
   % \settrue \c_page_lines_fake_number
   \else
   % \setfalse\c_page_lines_fake_number
     \edef\currentlinenumbering{#tag}%
     \def\linenumber{#linenumber}% unsafe
     \d_page_lines_line_width#width\scaledpoint\relax
     \d_page_lines_distance\linenumberingparameter\c!distance\relax
     \edef\p_align{\linenumberingparameter\c!align}%
     \edef\p_location{\linenumberingparameter\c!location}%
     \ifcase\istltdir#dir\relax
       \settrue \c_page_lines_dir_left_to_right
     \else
       \setfalse\c_page_lines_dir_left_to_right
     \fi
     %
     % maybe we also need an option to ignore columns, so that we renumber
     % once but on the other hand this assumes aligned lines
     %
     \ifcase\c_page_lines_last_column\relax
       \settrue \c_page_lines_fake_number % why
     \or
       % one column
     \or
       % two columns
       \ifx\p_location\v!default % or just margin
         \ifcase\c_page_lines_column\relax
           \settrue \c_page_lines_fake_number % why
         \or
           % one
           \let\p_location\v!left
         \else
           % two
           \let\p_location\v!right
           % can become a helper
           \page_line_swap_align
         \fi
       \fi
     \else
       % too fuzzy
     \fi
     \ifx\p_location\v!default
        \ifconditional\c_page_lines_dir_left_to_right
          \let\p_location\v!left
        \else
          \let\p_location\v!right
          \page_line_swap_align % yes or no
        \fi
     \fi
     %
     \executeifdefined{\??linenumberinghandler\p_location}\relax
   \fi
   \egroup}

\def\page_lines_number_inject#align#width%
  {\edef\p_width{\linenumberingparameter\c!width}%
   \ifx\p_width\v!margin
     \d_page_lines_width#width%
   \else
     \d_page_lines_width\p_width
   \fi
   \relax
   \ifdim\d_page_lines_width>\zeropoint
%      \ifconditional\c_page_lines_dir_left_to_right\else
%        \let\simplealignedbox\simplereversealignedbox
%      \fi
     \ifconditional\tracelinenumbering
       \ruledhbox{\simplealignedbox\d_page_lines_width#align{\page_lines_number_inject_indeed}}%
     \else
       \simplealignedbox\d_page_lines_width#align{\page_lines_number_inject_indeed}%
     \fi
   \else
     \ifconditional\tracelinenumbering
       \ruledhbox
     \else
     % \hbox
     \fi
     {\page_lines_number_inject_indeed}%
   \fi}

\def\page_lines_number_inject_indeed
  {\uselinenumberingstyleandcolor\c!style\c!color
   \linenumberingparameter\c!command
     {\linenumberingparameter\c!left
      \convertnumber{\linenumberingparameter\c!conversion}\linenumber
      \linenumberingparameter\c!right}}

% \def\dodorlap{\hbox to \zeropoint{\box\nextbox\normalhss}\endgroup}
% \def\dodollap{\hbox to \zeropoint{\normalhss\box\nextbox}\endgroup}

\def\page_line_handle_left#align#width#distance%
  {\llap
     {\page_lines_number_inject#align#width%
      \kern\dimexpr#distance+\d_page_lines_distance\relax
      \the\everylinenumber
      \hss}}

\def\page_line_handle_right#align#width#distance%
  {\rlap
     {\kern\dimexpr#distance+\d_page_lines_distance+\d_page_lines_line_width\relax
      \page_lines_number_inject#align#width%
      \the\everylinenumber}}

\setuvalue{\??linenumberinghandler\v!left}%
  {\page_line_handle_left\p_align\leftmarginwidth\leftmargindistance}

\setuvalue{\??linenumberinghandler\v!right}%
  {\page_line_handle_right\p_align\rightmarginwidth\rightmargindistance}

\setuvalue{\??linenumberinghandler\v!inner}%
  {\ifodd\realpageno
     \ifx\p_align\v!inner
       \page_line_handle_left\v!flushleft\leftmarginwidth\leftmargindistance
     \else\ifx\p_align\v!outer
       \page_line_handle_left\v!flushright\leftmarginwidth\leftmargindistance
     \else
       \page_line_handle_left\p_align\leftmarginwidth\leftmargindistance
     \fi\fi
   \else
     \ifx\p_align\v!inner
       \page_line_handle_right\v!flushright\rightmarginwidth\rightmargindistance
     \else\ifx\p_align\v!outer
       \page_line_handle_right\v!flushleft\rightmarginwidth\rightmargindistance
     \else
       \page_line_handle_right\p_align\rightmarginwidth\rightmargindistance
     \fi\fi
   \fi}

\setuvalue{\??linenumberinghandler\v!outer}%
  {\ifodd\realpageno
     \ifx\p_align\v!inner
       \page_line_handle_right\v!flushleft\leftmarginwidth\leftmargindistance
     \else\ifx\p_align\v!outer
       \page_line_handle_right\v!flushright\leftmarginwidth\leftmargindistance
     \else
       \page_line_handle_right\p_align\leftmarginwidth\leftmargindistance
     \fi\fi
   \else
     \ifx\p_align\v!inner
       \page_line_handle_left\v!flushright\rightmarginwidth\rightmargindistance
     \else\ifx\p_align\v!outer
       \page_line_handle_left\v!flushleft\rightmarginwidth\rightmargindistance
     \else
       \page_line_handle_left\p_align\rightmarginwidth\rightmargindistance
     \fi\fi
   \fi}

\def\page_line_handle_begin#align%
  {\rlap
     {\kern\d_page_lines_distance
      \page_lines_number_inject#align\zeropoint
      \the\everylinenumber}}

\def\page_line_handle_end#align%
  {\rlap
     {\kern\d_page_lines_line_width\relax
      \llap
        {\page_lines_number_inject#align\zeropoint
         \kern\d_page_lines_distance
         \the\everylinenumber}}}

\setuvalue{\??linenumberinghandler\v!begin}{\page_line_handle_begin\p_align}
\setuvalue{\??linenumberinghandler\v!end  }{\page_line_handle_end  \p_align}
\setuvalue{\??linenumberinghandler\v!text }{\page_line_handle_begin\p_align}

\setuevalue{\??linenumberinghandler\v!inleft  }{\getvalue{\??linenumberinghandler\v!left }}
\setuevalue{\??linenumberinghandler\v!inmargin}{\getvalue{\??linenumberinghandler\v!left }}
\setuevalue{\??linenumberinghandler\v!margin  }{\getvalue{\??linenumberinghandler\v!left }}
\setuevalue{\??linenumberinghandler\v!inright }{\getvalue{\??linenumberinghandler\v!right}}

% referencing: \permithyphenation, also removes leading spaces (new per 29-11-2013)

\unexpanded\def\someline [#1]{\page_lines_reference_start{#1}\page_lines_reference_stop{#1}} % was just a def
\unexpanded\def\startline[#1]{\page_lines_reference_start{#1}\ignorespaces}
\unexpanded\def\stopline [#1]{\removeunwantedspaces\permithyphenation\page_lines_reference_stop{#1}}

\def\page_lines_reference_show_start
  {\ifconditional\tracelinenumbering
     \expandafter\page_lines_reference_show_start_indeed
   \else
     \expandafter\gobbleoneargument
   \fi}

\def\page_lines_reference_show_stop
  {\ifconditional\tracelinenumbering
     \expandafter\page_lines_reference_show_stop_indeed
   \else
     \expandafter\gobbleoneargument
   \fi}

\def\page_lines_reference_show_start_indeed#1%
  {\setbox\scratchbox\hbox{\llap
     {\vrule\s!width\onepoint\s!depth\strutdp\s!height.8\strutht\raise.85\strutht\hbox{\llap{\tt\txx#1}}}}%
   \smashbox\scratchbox
   \box\scratchbox}

\def\page_lines_reference_show_stop_indeed#1%
  {\setbox\scratchbox\hbox{\rlap
     {\raise.85\strutht\hbox{\rlap{\tt\txx#1}}\vrule\s!width\onepoint\s!depth\strutdp\s!height.8\strutht}}%
   \smashbox\scratchbox
   \box\scratchbox}

\def\page_lines_reference_start#1{\page_lines_some_reference{#1}{lr:b:#1}{\page_lines_reference_show_start{#1}}}
\def\page_lines_reference_stop #1{\page_lines_some_reference{#1}{lr:e:#1}{\page_lines_reference_show_stop {#1}}}

% eventually we will do this in lua

\def\currentreferencelinenumber{\clf_filterreference{linenumber}}

\let\m_page_lines_from\empty
\let\m_page_lines_to  \empty

\unexpanded\def\doifelsesamelinereference#1#2#3%
  {\doifelsereferencefound{lr:b:#1}
     {\edef\m_page_lines_from{\currentreferencelinenumber}%
      \doifelsereferencefound{lr:e:#1}
        {\edef\m_page_lines_to{\currentreferencelinenumber}%
         %[\m_page_lines_from,\m_page_lines_to]
         \ifx\m_page_lines_from\m_page_lines_to#2\else#3\fi}
        {#2}}
     {#2}}

\let\doifsamelinereferenceelse\doifelsesamelinereference

\unexpanded\def\inline#1[#2]%
  {\doifelsenothing{#1}
     {\doifelsesamelinereference{#2}
        {\in{\leftlabeltext\v!line}{\rightlabeltext\v!line}[lr:b:#2]}
        {\in{\leftlabeltext\v!lines}{}[lr:b:#2]--\in{}{\rightlabeltext\v!lines}[lr:e:#2]}}
     {\doifelsesamelinereference{#2}
        {\in{#1}[lr:b:#2]}
        {\in{#1}[lr:b:#2]--\in[lr:e:#2]}}}

\unexpanded\def\inlinerange[#1]%
  {\doifelsesamelinereference{#1}
     {\in[lr:b:#1]}
     {\in[lr:b:#1]\endash\in[lr:e:#1]}}

\protect \endinput
