-----------------------------------------------------------------------
-- RTF exporter in Lua for SciTE
-- Version 0.9.3, 20070805
--
-- Adapted from SciTE sources (scite/src/Exporters.cxx CVS 20040723)
-- by Kein-Hong Man <khman@users.sf.net> (This is a straightforward
-- conversion and so I decline to claim it as my own.)
--
-- Copyright 1998-2007 by Neil Hodgson <neilh@scintilla.org>
-- All Rights Reserved
--
-- Permission to use, copy, modify, and distribute this software and
-- its documentation for any purpose and without fee is hereby granted,
-- provided that the above copyright notice appear in all copies and
-- that both that copyright notice and this permission notice appear in
-- supporting documentation.
--
-- NEIL HODGSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
-- INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
-- NO EVENT SHALL NEIL HODGSON BE LIABLE FOR ANY SPECIAL, INDIRECT OR
-- CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
-- OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
-- NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
-- WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--
-----------------------------------------------------------------------
-- USAGE
--
-- * Please see SciTELuaExporters.html for notes on how to get this
--   exporter up and running.
-- * Requires SciTE_ExportBase.lua to be loaded first.
-- * The start and end arguments to the RTF function have been removed
--   but they can be implemented without too much trouble.
-- * Has been tested casually with these lexers: lua, props, cpp and
--   basic text, giving byte-for-byte identical output.
-----------------------------------------------------------------------

-----------------------------------------------------------------------
-- a simple check to alert of namespace collision, but allows different
-- files to define their own functions in the exporters table
-----------------------------------------------------------------------
if exporters then
  if exporters.SaveToRTF then
    error("SciTE_ExporterRTF: exporters.SaveToRTF already defined")
  end
else
  exporters = {}
end

-----------------------------------------------------------------------
-- exporters:SaveToRTF
--
-- Exports the document in the current window to a RTF format file.
--
-----------------------------------------------------------------------
function exporters:SaveToRTF()
  local selBeg, selEnd = exportutil.GetSelPos()
  local RTFDefaultTabSize = 4

  local RTF_HEADEROPEN = "{\\rtf1\\ansi\\deff0\\deftab720"
  local RTF_FONTDEFOPEN = "{\\fonttbl"
  local RTF_FONTDEF = "{\\f%d\\fnil\\fcharset%u %s;}"
  local RTF_FONTDEFCLOSE = "}"
  local RTF_COLORDEFOPEN = "{\\colortbl"
  local RTF_COLORDEF = "\\red%d\\green%d\\blue%d;"
  local RTF_COLORDEFCLOSE = "}"
  local RTF_HEADERCLOSE = "\n"
  local RTF_BODYOPEN = ""
  local RTF_BODYCLOSE = "}"

  local RTF_SETFONTFACE = "\\f"
  local RTF_SETFONTSIZE = "\\fs"
  local RTF_SETCOLOR = "\\cf"
  local RTF_SETBACKGROUND = "\\highlight"
  local RTF_BOLD_ON = "\\b"
  local RTF_BOLD_OFF = "\\b0"
  local RTF_ITALIC_ON = "\\i"
  local RTF_ITALIC_OFF = "\\i0"
  local RTF_UNDERLINE_ON = "\\ul"
  local RTF_UNDERLINE_OFF = "\\ulnone"
  local RTF_STRIKE_ON = "\\i"
  local RTF_STRIKE_OFF = "\\strike0"

  local RTF_EOLN = "\\par\n"
  local RTF_TAB = "\\tab "

  local MAX_STYLEDEF = 128
  local MAX_FONTDEF = 64
  local MAX_COLORDEF = 8
  local RTF_FONTFACE = "Courier New"
  local RTF_COLOR = "#000000"

  -- the original C code was rather bizzare...
  local function GetRTFStyleChange(last, current) -- \f0\fs20\cf0\highlight0\b0\i0
    local function GetNextElem(style)
      local x, y = string.find(style, "\\", 2, 1)
      if not x then return style, "" end
      return string.sub(style, 1, x - 1), string.sub(style, x, -1)
    end
    local lastElem, currentElem
    local delta = ""
    -- font face, size, color, background, bold, italic
    for i = 1,6 do
      lastElem, last = GetNextElem(last)
      currentElem, current = GetNextElem(current)
      if lastElem ~= currentElem then -- change
        delta = delta..currentElem
      end
    end
    if delta ~= "" then
      delta = delta.." "
    end
    return delta
  end

  -- local lengthDoc = editor.Length
  editor:Colourise(0, -1)

  -- Read the default settings
  stylemgr:setlexer(editor.Lexer)
  local defaultStyle = stylemgr.styles[32]

  local tabSize = tonumber(props["export.rtf.tabsize"])
  if not tabSize or tabSize == 0 then
    tabSize = tonumber(props["tabsize"])
    if not tabSize or tabSize == 0 then
      tabSize = RTFDefaultTabSize
    end
  end
  local wysiwyg = tonumber(props["export.rtf.wysiwyg"]) or 1
  local fontFace = props["export.rtf.font.face"]
  if fontFace and fontFace ~= "" then
    defaultStyle.font = fontFace
  elseif defaultStyle.font == "" then
    defaultStyle.font = RTF_FONTFACE
  end
  local fontSize = tonumber(props["export.rtf.font.size"]) or 0
  if fontSize > 0 then
    defaultStyle.size = fontSize * 2
  elseif defaultStyle.size == 0 then
    defaultStyle.size = 10 * 2
  else
    defaultStyle.size = defaultStyle.size * 2
  end
  local characterset = tonumber(props["character.set"]) or SC_CHARSET_DEFAULT
  local tabs = tonumber(props["export.rtf.tabs"]) or false

  local saveName = exportutil.exportfile(props["FileDir"], props["FileName"], "rtf")
  local fp = io.open(saveName, "wt")
  if not fp then
    error("exporters:SaveToRTF: could not save file \""..saveName.."\"")
  end
  if exportutil.VERBOSE ~= 0 then
    _ALERT("\nExporting to RTF, filepath: "..saveName)
  end

  local styles = {}
  local fonts = {}
  local colors = {}
  local lastStyle, deltaStyle
  local fontCount = 1
  local colorCount = 2
  local ifound
  fp:write(RTF_HEADEROPEN..RTF_FONTDEFOPEN);
  fonts[1] = defaultStyle.font
  fp:write(string.format(RTF_FONTDEF, 0, characterset, defaultStyle.font))
  colors[1] = defaultStyle.fore
  colors[2] = defaultStyle.back

  for istyle = 0, exportutil.STYLE_DEFAULT - 1 do
    local sd = stylemgr:locate(istyle)
    if sd.specified ~= "" then
      if wysiwyg and string.match(sd.specified, "font") then
        ifound = nil
        for i = 1, fontCount do
          if string.lower(sd.font) == string.lower(fonts[i]) then
            ifound = i; break
          end
        end
        if not ifound then
          fontCount = fontCount + 1
          fonts[fontCount] = sd.font
          ifound = fontCount
          fp:write(string.format(RTF_FONTDEF, ifound - 1, characterset, sd.font))
        end
        lastStyle = RTF_SETFONTFACE..(ifound - 1)
      else
        lastStyle = RTF_SETFONTFACE.."0"
      end
      lastStyle = lastStyle..RTF_SETFONTSIZE
      if wysiwyg and string.match(sd.specified, "size") then
        lastStyle = lastStyle..(sd.size * 2)
      else
        lastStyle = lastStyle..defaultStyle.size
      end
      if string.match(sd.specified, "fore") then
        ifound = nil
        for i = 1, colorCount do
          if stylemgr:hexstr(sd.fore) == stylemgr:hexstr(colors[i]) then
            ifound = i; break
          end
        end
        if not ifound then
          colorCount = colorCount + 1
          colors[colorCount] = sd.fore
          ifound = colorCount
        end
        lastStyle = lastStyle..RTF_SETCOLOR..(ifound - 1)
      else
        lastStyle = lastStyle..RTF_SETCOLOR.."0"        -- Default fore
      end
      if string.match(sd.specified, "back") then
        ifound = nil
        for i = 1, colorCount do
          if stylemgr:hexstr(sd.back) == stylemgr:hexstr(colors[i]) then
            ifound = i; break
          end
        end
        if not ifound then
          colorCount = colorCount + 1
          colors[colorCount] = sd.back
          ifound = colorCount
        end
        lastStyle = lastStyle..RTF_SETBACKGROUND..(ifound - 1)
      else
        lastStyle = lastStyle..RTF_SETBACKGROUND.."1"   -- Default back
      end
      if string.match(sd.specified, "bold") then
        lastStyle = lastStyle..(sd.bold and RTF_BOLD_ON or RTF_BOLD_OFF)
      else
        lastStyle = lastStyle..(defaultStyle.bold and RTF_BOLD_ON or RTF_BOLD_OFF)
      end
      if string.match(sd.specified, "italics") then
        lastStyle = lastStyle..(sd.italics and RTF_ITALIC_ON or RTF_ITALIC_OFF)
      else
        lastStyle = lastStyle..(defaultStyle.italics and RTF_ITALIC_ON or RTF_ITALIC_OFF)
      end
      styles[istyle] = lastStyle
    else
      styles[istyle] = RTF_SETFONTFACE.."0"..RTF_SETFONTSIZE..defaultStyle.size..
                       RTF_SETCOLOR.."0"..RTF_SETBACKGROUND.."1"..
                       RTF_BOLD_OFF..RTF_ITALIC_OFF
    end--if sd.specified
  end--for

  fp:write(RTF_FONTDEFCLOSE..RTF_COLORDEFOPEN)
  for i = 1, colorCount do
    fp:write(string.format(RTF_COLORDEF, colors[i].r, colors[i].g, colors[i].b))
  end

  fp:write(RTF_COLORDEFCLOSE..RTF_HEADERCLOSE..RTF_BODYOPEN..RTF_SETFONTFACE.."0"..
           RTF_SETFONTSIZE..defaultStyle.size..RTF_SETCOLOR.."0 ")
  lastStyle = RTF_SETFONTFACE.."0"..RTF_SETFONTSIZE..defaultStyle.size..
              RTF_SETCOLOR.."0"..RTF_SETBACKGROUND.."1"..
              RTF_BOLD_OFF..RTF_ITALIC_OFF

  local prevCR = false
  local styleCurrent = -1
  local column = 0
  for i = selBeg, selEnd - 1 do
    local ch = exportutil.CharAt(i)
    local style = exportutil.StyleAt(i)

    if style > STYLE_DEFAULT then
      style = 0
    end
    if style ~= styleCurrent then
      deltaStyle = GetRTFStyleChange(lastStyle, styles[style])
      if deltaStyle ~= "" then fp:write(deltaStyle) end
      lastStyle = styles[style]
      styleCurrent = style
    end
    if ch == "{" then
      fp:write("\\{")
    elseif ch == "}" then
      fp:write("\\}")
    elseif ch == "\\" then
      fp:write("\\\\")
    elseif ch == "\t" then
      if tabs then
        fp:write(RTF_TAB)
      else
        local ts = tabSize - column % tabSize
        fp:write(string.rep(' ', ts))
        column = column + ts - 1
      end
    elseif ch == "\n" then
      if not prevCR then
        fp:write(RTF_EOLN)
        column = -1
      end
    elseif ch == "\r" then
      fp:write(RTF_EOLN)
      column = -1
    else
      fp:write(ch)
    end--ch
    column = column + 1
    prevCR = ch == "\r"
  end--for

  fp:write(RTF_BODYCLOSE)
  fp:close()
  if exportutil.VERBOSE ~= 0 then
    exportutil.progress("... done.")
  end
end

-- end of script