%D \module
%D   [       file=m-ipsum,
%D        version=2012.07.19,
%D          title=\CONTEXT\ Extra Modules,
%D       subtitle=Ipsum,
%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.

%D After some discussing on the mailing list I made this example of
%D an implementation. Of course there can be alternatives as it's a
%D nice exercise in module writing.

\startluacode

local patterns     = lpeg.patterns

local variables    = interfaces.variables
local v_random     = variables.random

local lowercase    = characters.lower

local ipsum        = { }
moduledata.ipsum   = ipsum

local data         = { }

local function getfiledata(settings)
    local filename = settings.filename or ""
    local filedata = data[filename]
    if not filedata then
        local text = resolvers.loadtexfile(filename) or ""
        local paragraphs = lpeg.match(patterns.paragraphs,text) or { }
        local sentences  = lpeg.match(patterns.sentences, text) or { }
        local words      = lpeg.match(patterns.words,     text) or { }
        for i=1,#words do
            words[i] = lowercase(words[i])
        end
        filedata = {
         -- [variables.paragraphs] = paragraphs,
            [variables.paragraph]  = paragraphs,
            [variables.lines]      = sentences,
            [variables.line]       = sentences,
            [variables.words]      = words,
            [variables.word]       = words,
        }
     -- inspect(filedata)
        data[filename] = filedata
    end
    local d = filedata[settings.alternative or v_paragraph] or filedata[v_paragraph] or { }
    local nd = #d
    local n = settings.n
    if n ~= v_random then
        n = tonumber(n) or 0
        if n == 0 then
            n = nd
        end
    end
    return d, n, nd
end

function moduledata.ipsum.typeset(settings)
    local d, n, nd = getfiledata(settings)
    if nd > 0 then
        context(settings.before)
        if n == v_random then
            context(settings.left)
            context(d[math.random(1,nd)])
            context(settings.right)
        else
            for i=1,n do
                context(settings.left)
                context(d[i])
                context(settings.right)
                if i < n then
                    context(settings.inbetween)
                end
            end
        end
        context(settings.after)
    end
end

function moduledata.ipsum.direct(settings)
    local d, n, nd = getfiledata(settings)
    if nd == 0 then
        -- nothing
    elseif n == v_random then
        context(d[math.random(1,nd)])
    else
        for i=1,n do
            context(d[i])
            if i < n then
                context(settings.separator)
            end
        end
    end
end

interfaces.implement {
    name      = "ipsum",
    protected = true,
    actions   = moduledata.ipsum.typeset,
    arguments = { {
        { "alternative" },
        { "filename" },
        { "n" },
        { "left" },
        { "right" },
        { "before" },
        { "after" },
        { "inbetween" },
        { "separator" },
    } },
}

\stopluacode

\unprotect

\installnamespace {ipsum}

\installcommandhandler \????ipsum {ipsum} \????ipsum

\setupipsum
  [\c!file=lorem,
   \c!alternative=\v!paragraph,
  %\c!language=,
  %\c!styl=,
  %\c!color=,
   \c!n=0,
   \c!left=,
   \c!right=,
   \c!before=,
   \c!after=,
   \c!separator=,
   \c!inbetween=]

\installactionhandler{ipsum} % grouped

\startsetups[handler:action:ipsum]
   \useipsumstyleandcolor\c!style\c!color
   % hm, also changes dates
   \uselanguageparameter\ipsumparameter
   \clf_ipsum
      alternative {\ipsumparameter\c!alternative}
      filename    {\ipsumparameter\c!file}
      n           {\ipsumparameter\c!n}
      left        {\ipsumparameter\c!left}
      right       {\ipsumparameter\c!right}
      before      {\ipsumparameter\c!before}
      after       {\ipsumparameter\c!after}
      inbetween   {\ipsumparameter\c!inbetween}
   \relax
\stopsetups

\def\directipsum#1% only one argument, expanded
  {\clf_ipsum
      alternative {\namedipsumparameter{#1}\c!alternative}
      filename    {\namedipsumparameter{#1}\c!file}
      n           {\namedipsumparameter{#1}\c!n}
      separator   {\ipsumparameter\c!separator}
   \relax}

\protect

\continueifinputfile{m-ipsum.mkiv}

\setupbodyfont[dejavu,11pt]

\starttext

    \ipsum[alternative=paragraph,before=\blank,after=\blank,language=la]

    \ipsum[alternative=lines,n=2,right=\par,before=\blank,after=\blank,language=la]

    \ipsum[alternative=lines,n=random,before=\blank,after=\blank,language=la]

    \ipsum[alternative=lines,before=\startitemize,after=\stopitemize,left=\startitem,right=\stopitem,language=la]

    \ipsum[alternative=words,left=(,right=),inbetween=\space,language=la]

    \page

    \defineipsum
      [ward]
      [file=ward,
       before=\blank,
       after=\blank]

    \defineipsum
      [ward:itemize]
      [ward]
      [alternative=lines,
       before={\startitemize[packed]},
       after=\stopitemize,
       left=\startitem,
       right=\stopitem]

    \defineipsum
      [ward:title]
      [ward]
      [alternative=lines,
       n=random]

    \subject{\directipsum{ward:title}}

    \ipsum[ward]
    \ipsum[ward:itemize]

\stoptext
