%D \module
%D   [       file=m-scite,
%D        version=2014.04.28,
%D          title=\CONTEXT\ Extra Modules,
%D       subtitle=\SCITE\ lexers,
%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.

% We can simplify the scite lexers, as long as we're able to return the
% lexed result table and provide alexer module with the functions that
% the lexer expects (so I need to decipher the cxx file).
%
% lexer._TOKENSTYLES : table
% lexer._CHILDREN    : flag
% lexer._EXTRASTYLES : table
% lexer._GRAMMAR     : flag
%
% lexers.load        : function
% lexers.lex         : function
%
% And some properties that map styles onto scintilla styling. I get the
% impression that we end up with something simpler, a hybrid between the
% scite lexing and the current context way, so we get an intermediate
% step, with some penalty for context, but at least I don't have to
% maintain two sets (three sets as we also have a line based series).

% TODO: as these files are in tds we can locate them and set the lexer root
% to that one. Currently we're on: we're on context/documents.

% TODO: tab

% This is an experiment: eventually we need to hook it into the verbatim code
% and deal with widow lines and so.

\startluacode

-- todo: merge with collapse
-- todo: prehash whitespaces

-- todo: hook into the pretty print code
-- todo: a simple catcode regime with only \ { }

local gsub, sub, find = string.gsub, string.sub, string.find
local concat = table.concat
local formatters = string.formatters
local lpegmatch = lpeg.match
local setmetatableindex = table.setmetatableindex

local scite   = require("util-sci")
buffers.scite = scite

-- context output:

local f_def_color = formatters["\\definecolor[slxc%s][h=%02X%02X%02X]%%"]
local f_fore_none = formatters["\\unexpanded\\def\\slx%s#1{{\\slxc%s#1}}%%"]
local f_fore_bold = formatters["\\unexpanded\\def\\slx%s#1{{\\slxc%s\\bf#1}}%%"]
local f_none_bold = formatters["\\unexpanded\\def\\slx%s#1{{\\bf#1}}%%"]
local f_none_none = formatters["\\unexpanded\\def\\slx%s#1{{#1}}%%"]
local f_texstyled = formatters["\\slx%s{%s}"]
local f_hanging   = formatters["\\slxb{%s}%s\\slxe"]


local f_mapping   = [[
\let\string\slxL\string\letterleftbrace
\let\string\slxR\string\letterrightbrace
\let\string\slxM\string\letterdollar
\let\string\slxV\string\letterbar
\let\string\slxU\string\letterhat
\let\string\slxD\string\letterunderscore
\let\string\slxH\string\letterhash
\let\string\slxB\string\letterbackslash
\let\string\slxP\string\letterpercent
\let\string\slxT\string\lettertilde
\let\string\slxS\string\fixedspace
%]]

local replacer = lpeg.replacer {
    ["{"]  = "\\slxL ",
    ["}"]  = "\\slxR ",
    ["$"]  = "\\slxM ",
    ["^"]  = "\\slxU ",
    ["_"]  = "\\slxD ",
    ["|"]  = "\\slxV ",
    ["#"]  = "\\slxH ",
    ["\\"] = "\\slxB ",
    ["%"]  = "\\slxP ",
    ["~"]  = "\\slxT ",
    [" "]  = "\\slxS ", -- can be made more efficient: \\slxF{n}
}

local colors = nil

local function exportcolors()
    if not colors then
        scite.loadscitelexer()
        local function black(f)
            return (f[1] == f[2]) and (f[2] == f[3]) and (f[3] == 0)
        end
        local result, r = { f_mapping }, 1
        for k, v in table.sortedhash(lexer.context.styles) do
            local fore = v.fore
            if fore and not black(fore) then
                r = r + 1
                result[r] = f_def_color(k,fore[1],fore[2] or fore[1],fore[3] or fore[1])
            end
        end
        r = r + 1
        result[r] = "%"
        for k, v in table.sortedhash(lexer.context.styles) do
            local bold = v.bold
            local fore = v.fore
            r = r + 1
            if fore and not black(fore) then
                if bold then
                    result[r] = f_fore_bold(k,k)
                else
                    result[r] = f_fore_none(k,k)
                end
            else
                if bold then
                    result[r] = f_none_bold(k)
                else
                    result[r] = f_none_none(k)
                end
            end
        end
        colors = concat(result,"\n")
    end
    return colors
end

local function exportwhites()
    return setmetatableindex(function(t,k)
        local v = find(k,"white") and true or false
        t[k] = v
        return v
    end)
end

local function exportstyled(lexer,text)
    local result = lexer.lex(lexer,text,0)
    local start = 1
    local whites = exportwhites()
    local buffer = { }
    for i=1,#result,2 do
        local style = result[i]
        local position = result[i+1]
        local txt = sub(text,start,position-1)
        txt = lpegmatch(replacer,txt)
        if whites[style] then
            buffer[#buffer+1] = txt
        else
            buffer[#buffer+1] = f_texstyled(style,txt)
        end
        start = position
    end
    buffer = concat(buffer)
    return buffer
end

function scite.installcommands()
    context(exportcolors())
end

local p1 = lpeg.tsplitat(lpeg.patterns.newline)
local p2 = lpeg.P("\\slxS ")^1
local p3 = lpeg.Cs((lpeg.Cp() * lpeg.P(" ") * lpeg.Cp() / function(b,e) return "\\slxF{" .. (e-b-1) .. "}" end
         + (1-lpeg.P(" "))^1)^0)

-- slxb could have a \hskip so then we can replace the slxS's

local function indent(str)
    local l = lpegmatch(p1,str)
    for i=1,#l do
        local s = l[i]
        if #s > 0 then
            local n = lpegmatch(p2,s)
            if n then
                n = (n-1)/6
            else
                n = 0
            end
s = lpegmatch(p3,s) -- can be combined
            l[i] = f_hanging(n,s) -- "\\slxb{%s}%s\\slxe "
-- print(">",s)
-- print("<",l[i])
        end
    end
    return concat(l,"\n")
end

local function lexdata(data,lexname)
    local styled = exportstyled(scite.loadedlexers[lexname],data or "")
    styled = indent(styled)
    buffers.assign("lex",styled)
end

scite.lexdata = lexdata

function scite.lexbuffer(name,lexname)
    lexdata(buffers.getcontent(name) or "",lexname or "tex")
end

function scite.lexfile(filename,lexname)
    lexdata(io.loaddata(filename) or "",lexname or file.suffix(filename))
end

-- html output

\stopluacode

% This is a preliminary interface.

\unprotect

\newdimen\scitespaceskip

\unexpanded\def\buff_scite_slxb#1%
  {%\begingroup
   \hangindent\numexpr#1+2\relax\scitespaceskip
   \hangafter 1\relax}

\unexpanded\def\buff_scite_slxe
  {\par
   }%\endgroup}

\unexpanded\def\installscitecommands
  {\ctxlua{buffers.scite.installcommands()}%
   \let\installscitecommands\relax
   \scitespaceskip\fontcharwd\font`0\relax
   \unexpanded\def\slxS{\hskip\scitespaceskip}%
   \unexpanded\def\slxF##1{\hskip##1\scitespaceskip\relax}%
   \let\slxb\buff_scite_slxb
   \let\slxe\buff_scite_slxe}

\unexpanded\def\startscite
  {\begingroup
   \dosingleempty\buff_scite_start}

\def\buff_scite_start[#1]%
  {\edef\currentscitelexer{#1}%
   \dostartbuffer[@scite@][startscite][stopscite]}

\unexpanded\def\stopscite
  {\scitebuffer[\ifx\currentscitelexer\empty tex\else\currentscitelexer\fi][@scite@]%
   \endgroup}

\unexpanded\def\scitefile
  {\dosingleargument\module_scite_file}

\unexpanded\def\module_scite_file[#1]%
  {\start
   \ctxlua{buffers.scite.lexfile("#1")}%
   \installscitecommands
   \tt
   \dontcomplain
   \raggedright
   \startcontextcode
   \startlines
   \getbuffer[lex]
   \stoplines
   \stopcontextcode
   \stop}

\unexpanded\def\scitebuffer
  {\dodoubleargument\module_scite_buffer}

\unexpanded\def\module_scite_buffer[#1][#2]%
  {\start
   \ifsecondargument
     \ctxlua{buffers.scite.lexbuffer("#2","#1")}%
   \else
     \ctxlua{buffers.scite.lexbuffer("#1","tex")}%
   \fi
   \installscitecommands
   \tt
   \dontcomplain
   \raggedright
   \setcatcodetable\ctxcatcodes % needed in xml
   \startlines
   \getbuffer[lex]%
   \stoplines
   \stop}

\protect

\continueifinputfile{m-scite.mkiv}

\setupbodyfont[dejavu,8pt]

\setuplayout
  [width=middle,
   height=middle,
   header=1cm,
   footer=1cm,
   topspace=1cm,
   bottomspace=1cm,
   backspace=1cm]

\startbuffer[demo]
\startsubsubject[title={oeps}]

\startMPcode
    draw fullcircle
        scaled 2cm
        withpen pencircle scaled 1mm
        withcolor .5green;
    draw textext (
        lua (
            "local function f(s) return string.upper(s) end mp.quoted(f('foo'))"
        )
    ) withcolor .5red ;
\stopMPcode

\startluacode
    context("foo")
\stopluacode

\stopsubsubject
\stopbuffer

\starttext

% \scitefile[../lexers/scite-context-lexer.lua]  \page
% \scitefile[t:/manuals/about/about-metafun.tex] \page
% \scitefile[t:/sources/strc-sec.mkiv]           \page
% \scitefile[e:/tmp/mp.w]                        \page
% \scitefile[t:/manuals/hybrid/tugboat.bib]        \page
\scitefile[e:/tmp/test.bib]        \page

% \getbuffer[demo] \scitebuffer[demo]

\stoptext