{-
Copyright (C) 2008 John MacFarlane <jgm@berkeley.edu>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}

{- |
   Module      : Text.Pandoc.Writers.MediaWiki 
   Copyright   : Copyright (C) 2006-7 John MacFarlane
   License     : GNU GPL, version 2 or above 

   Maintainer  : John MacFarlane <jgm@berkeley.edu>
   Stability   : alpha
   Portability : portable

Conversion of 'Pandoc' documents to MediaWiki markup.

MediaWiki:  <http://www.mediawiki.org/wiki/MediaWiki>
-}
module Text.Pandoc.Writers.MediaWiki ( writeMediaWiki ) where
import Text.Pandoc.Definition
import Text.Pandoc.Shared 
import Text.Pandoc.XML ( escapeStringForXML )
import Data.List ( intersect )
import Network.URI ( isURI )
import Control.Monad.State

data WriterState = WriterState {
    stNotes     :: Bool            -- True if there are notes
  , stListLevel :: [Char]          -- String at beginning of list items, e.g. "**"
  , stUseTags   :: Bool            -- True if we should use HTML tags because we're in a complex list
  }

-- | Convert Pandoc to MediaWiki.
writeMediaWiki :: WriterOptions -> Pandoc -> String
writeMediaWiki opts document = 
  evalState (pandocToMediaWiki opts document) 
            (WriterState { stNotes = False, stListLevel = [], stUseTags = False }) 

-- | Return MediaWiki representation of document.
pandocToMediaWiki :: WriterOptions -> Pandoc -> State WriterState String
pandocToMediaWiki opts (Pandoc _ blocks) = do
  let before  = writerIncludeBefore opts
  let after   = writerIncludeAfter opts
  let head' = if writerStandalone opts
                then writerHeader opts
                else ""
  let toc = if writerTableOfContents opts 
               then "__TOC__\n"
               else ""
  body <- blockListToMediaWiki opts blocks
  notesExist <- get >>= return . stNotes
  let notes = if notesExist
                 then "\n== Notes ==\n<references />"
                 else "" 
  return $ head' ++ before ++ toc ++ body ++ after ++ notes

-- | Escape special characters for MediaWiki.
escapeString :: String -> String
escapeString =  escapeStringForXML

-- | Convert Pandoc block element to MediaWiki. 
blockToMediaWiki :: WriterOptions -- ^ Options
                -> Block         -- ^ Block element
                -> State WriterState String 

blockToMediaWiki _ Null = return ""

blockToMediaWiki opts (Plain inlines) = 
  inlineListToMediaWiki opts inlines

blockToMediaWiki opts (Para inlines) = do
  useTags <- get >>= return . stUseTags
  listLevel <- get >>= return . stListLevel
  contents <- inlineListToMediaWiki opts inlines
  return $ if useTags
              then  "<p>" ++ contents ++ "</p>"
              else contents ++ if null listLevel then "\n" else ""

blockToMediaWiki _ (RawHtml str) = return str

blockToMediaWiki _ HorizontalRule = return "\n-----\n"

blockToMediaWiki opts (Header level inlines) = do
  contents <- inlineListToMediaWiki opts inlines
  let eqs = replicate (level + 1) '='
  return $ eqs ++ " " ++ contents ++ " " ++ eqs ++ "\n"

blockToMediaWiki _ (CodeBlock (_,classes,_) str) = do
  let at  = classes `intersect` ["actionscript", "ada", "apache", "applescript", "asm", "asp",
                       "autoit", "bash", "blitzbasic", "bnf", "c", "c_mac", "caddcl", "cadlisp", "cfdg", "cfm",
                       "cpp", "cpp-qt", "csharp", "css", "d", "delphi", "diff", "div", "dos", "eiffel", "fortran",
                       "freebasic", "gml", "groovy", "html4strict", "idl", "ini", "inno", "io", "java", "java5",
                       "javascript", "latex", "lisp", "lua", "matlab", "mirc", "mpasm", "mysql", "nsis", "objc",
                       "ocaml", "ocaml-brief", "oobas", "oracle8", "pascal", "perl", "php", "php-brief", "plsql",
                       "python", "qbasic", "rails", "reg", "robots", "ruby", "sas", "scheme", "sdlbasic",
                       "smalltalk", "smarty", "sql", "tcl", "", "thinbasic", "tsql", "vb", "vbnet", "vhdl", 
                       "visualfoxpro", "winbatch", "xml", "xpp", "z80"]
  let (beg, end) = if null at
                      then ("<pre>", "</pre>")
                      else ("<source lang=\"" ++ head at ++ "\">", "</source>")
  return $ beg ++ escapeString str ++ end

blockToMediaWiki opts (BlockQuote blocks) = do
  contents <- blockListToMediaWiki opts blocks
  return $ "<blockquote>" ++ contents ++ "</blockquote>" 

blockToMediaWiki opts (Table caption aligns widths headers rows) =  do
  let alignStrings = map alignmentToString aligns
  captionDoc <- if null caption
                   then return ""
                   else do
                     c <- inlineListToMediaWiki opts caption
                     return $ "<caption>" ++ c ++ "</caption>"
  colHeads <- colHeadsToMediaWiki opts alignStrings widths headers
  rows' <- mapM (tableRowToMediaWiki opts alignStrings) rows
  return $  "<table>\n" ++ captionDoc ++ colHeads ++ vcat rows' ++ "\n</table>"
 
blockToMediaWiki opts x@(BulletList items) = do
  oldUseTags <- get >>= return . stUseTags
  let useTags = oldUseTags || not (isSimpleList x)
  if useTags
     then do
        modify $ \s -> s { stUseTags = True }
        contents <- mapM (listItemToMediaWiki opts) items
        modify $ \s -> s { stUseTags = oldUseTags }
        return $ "<ul>\n" ++ vcat contents ++ "</ul>\n"
     else do
        modify $ \s -> s { stListLevel = stListLevel s ++ "*" }
        contents <- mapM (listItemToMediaWiki opts) items
        modify $ \s -> s { stListLevel = init (stListLevel s) }
        return $ vcat contents

blockToMediaWiki opts x@(OrderedList attribs items) = do
  oldUseTags <- get >>= return . stUseTags
  let useTags = oldUseTags || not (isSimpleList x)
  if useTags
     then do
        modify $ \s -> s { stUseTags = True }
        contents <- mapM (listItemToMediaWiki opts) items
        modify $ \s -> s { stUseTags = oldUseTags }
        return $ "<ol" ++ listAttribsToString attribs ++ ">\n" ++ vcat contents ++ "</ol>\n"
     else do
        modify $ \s -> s { stListLevel = stListLevel s ++ "#" }
        contents <- mapM (listItemToMediaWiki opts) items
        modify $ \s -> s { stListLevel = init (stListLevel s) }
        return $ vcat contents

blockToMediaWiki opts x@(DefinitionList items) = do
  oldUseTags <- get >>= return . stUseTags
  let useTags = oldUseTags || not (isSimpleList x)
  if useTags
     then do
        modify $ \s -> s { stUseTags = True }
        contents <- mapM (definitionListItemToMediaWiki opts) items
        modify $ \s -> s { stUseTags = oldUseTags }
        return $ "<dl>\n" ++ vcat contents ++ "</dl>\n"
     else do
        modify $ \s -> s { stListLevel = stListLevel s ++ ";" }
        contents <- mapM (definitionListItemToMediaWiki opts) items
        modify $ \s -> s { stListLevel = init (stListLevel s) }
        return $ vcat contents

-- Auxiliary functions for lists:

-- | Convert ordered list attributes to HTML attribute string
listAttribsToString :: ListAttributes -> String
listAttribsToString (startnum, numstyle, _) =
  let numstyle' = camelCaseToHyphenated $ show numstyle
  in  (if startnum /= 1
          then " start=\"" ++ show startnum ++ "\""
          else "") ++
      (if numstyle /= DefaultStyle
          then " style=\"list-style-type: " ++ numstyle' ++ ";\""
          else "")

-- | Convert bullet or ordered list item (list of blocks) to MediaWiki.
listItemToMediaWiki :: WriterOptions -> [Block] -> State WriterState String
listItemToMediaWiki opts items = do
  contents <- blockListToMediaWiki opts items
  useTags <- get >>= return . stUseTags
  if useTags
     then return $ "<li>" ++ contents ++ "</li>"
     else do
       marker <- get >>= return . stListLevel
       return $ marker ++ " " ++ contents

-- | Convert definition list item (label, list of blocks) to MediaWiki.
definitionListItemToMediaWiki :: WriterOptions
                             -> ([Inline],[Block]) 
                             -> State WriterState String
definitionListItemToMediaWiki opts (label, items) = do
  labelText <- inlineListToMediaWiki opts label
  contents <- blockListToMediaWiki opts items
  useTags <- get >>= return . stUseTags
  if useTags
     then return $ "<dt>" ++ labelText ++ "</dt>\n<dd>" ++ contents ++ "</dd>"
     else do
       marker <- get >>= return . stListLevel
       return $ marker ++ " " ++ labelText ++ "\n" ++ (init marker ++ ": ") ++  contents

-- | True if the list can be handled by simple wiki markup, False if HTML tags will be needed.
isSimpleList :: Block -> Bool
isSimpleList x =
  case x of
       BulletList items                 -> all isSimpleListItem items
       OrderedList (num, sty, _) items  -> all isSimpleListItem items &&
                                            num == 1 && sty `elem` [DefaultStyle, Decimal]
       DefinitionList items             -> all isSimpleListItem $ map snd items 
       _                                -> False

-- | True if list item can be handled with the simple wiki syntax.  False if
--   HTML tags will be needed.
isSimpleListItem :: [Block] -> Bool
isSimpleListItem []  = True
isSimpleListItem [x] =
  case x of
       Plain _           -> True
       Para  _           -> True
       BulletList _      -> isSimpleList x
       OrderedList _ _   -> isSimpleList x
       DefinitionList _  -> isSimpleList x
       _                 -> False
isSimpleListItem [x, y] | isPlainOrPara x =
  case y of
       BulletList _      -> isSimpleList y
       OrderedList _ _   -> isSimpleList y
       DefinitionList _  -> isSimpleList y
       _                 -> False
isSimpleListItem _ = False

isPlainOrPara :: Block -> Bool
isPlainOrPara (Plain _) = True
isPlainOrPara (Para  _) = True
isPlainOrPara _         = False

tr :: String -> String 
tr x =  "<tr>\n" ++ x ++ "\n</tr>"

-- | Concatenates strings with line breaks between them.
vcat :: [String] -> String
vcat []     = ""
vcat [x]    = x
vcat (x:xs) = x ++ "\n" ++ vcat xs

-- Auxiliary functions for tables:

colHeadsToMediaWiki :: WriterOptions
                    -> [[Char]]
                    -> [Float]
                    -> [[Block]]
                    -> State WriterState String
colHeadsToMediaWiki opts alignStrings widths headers = do
  heads <- sequence $ zipWith3 
           (\alignment columnwidth item -> tableItemToMediaWiki opts "th" alignment columnwidth item) 
           alignStrings widths headers
  return $ tr $ vcat heads

alignmentToString :: Alignment -> [Char]
alignmentToString alignment = case alignment of
                                 AlignLeft    -> "left"
                                 AlignRight   -> "right"
                                 AlignCenter  -> "center"
                                 AlignDefault -> "left"

tableRowToMediaWiki :: WriterOptions
                    -> [[Char]]
                    -> [[Block]]
                    -> State WriterState String
tableRowToMediaWiki opts aligns columns = 
  (sequence $ zipWith3 (tableItemToMediaWiki opts "td") aligns (repeat 0) columns) >>=
     return . tr . vcat

tableItemToMediaWiki :: WriterOptions
                     -> [Char]
                     -> [Char]
                     -> Float
                     -> [Block]
                     -> State WriterState String
tableItemToMediaWiki opts tag' align' width' item = do
  contents <- blockListToMediaWiki opts item
  let attrib = " align=\"" ++ align' ++ "\"" ++
               if width' /= 0
                  then " style=\"width: " ++ (show  (truncate (100 * width') :: Integer)) ++ "%;\""
                  else "" 
  return $ "<" ++ tag' ++ attrib ++ ">" ++ contents ++ "<" ++ tag' ++ ">"

-- | Convert list of Pandoc block elements to MediaWiki.
blockListToMediaWiki :: WriterOptions -- ^ Options
                    -> [Block]       -- ^ List of block elements
                    -> State WriterState String 
blockListToMediaWiki opts blocks =
  mapM (blockToMediaWiki opts) blocks >>= return . vcat

-- | Convert list of Pandoc inline elements to MediaWiki.
inlineListToMediaWiki :: WriterOptions -> [Inline] -> State WriterState String
inlineListToMediaWiki opts lst =
  mapM (inlineToMediaWiki opts) lst >>= return . concat

-- | Convert Pandoc inline element to MediaWiki.
inlineToMediaWiki :: WriterOptions -> Inline -> State WriterState String

inlineToMediaWiki opts (Emph lst) = do 
  contents <- inlineListToMediaWiki opts lst
  return $ "''" ++ contents ++ "''" 

inlineToMediaWiki opts (Strong lst) = do
  contents <- inlineListToMediaWiki opts lst
  return $ "'''" ++ contents ++ "'''"

inlineToMediaWiki opts (Strikeout lst) = do
  contents <- inlineListToMediaWiki opts lst
  return $ "<s>" ++ contents ++ "</s>"

inlineToMediaWiki opts (Superscript lst) = do
  contents <- inlineListToMediaWiki opts lst
  return $ "<sup>" ++ contents ++ "</sup>"

inlineToMediaWiki opts (Subscript lst) = do
  contents <- inlineListToMediaWiki opts lst
  return $ "<sub>" ++ contents ++ "</sub>"

inlineToMediaWiki opts (SmallCaps lst) = inlineListToMediaWiki opts lst

inlineToMediaWiki opts (Quoted SingleQuote lst) = do
  contents <- inlineListToMediaWiki opts lst
  return $ "&lsquo;" ++ contents ++ "&rsquo;"

inlineToMediaWiki opts (Quoted DoubleQuote lst) = do
  contents <- inlineListToMediaWiki opts lst
  return $ "&ldquo;" ++ contents ++ "&rdquo;"

inlineToMediaWiki opts (Cite _  lst) = inlineListToMediaWiki opts lst

inlineToMediaWiki _ EmDash = return "&mdash;"

inlineToMediaWiki _ EnDash = return "&ndash;"

inlineToMediaWiki _ Apostrophe = return "&rsquo;"

inlineToMediaWiki _ Ellipses = return "&hellip;"

inlineToMediaWiki _ (Code str) =
  return $ "<tt>" ++ (escapeString str) ++ "</tt>"

inlineToMediaWiki _ (Str str) = return $ escapeString str

inlineToMediaWiki _ (Math str) = return $ "<math>" ++ str ++ "</math>"
                                 -- note:  str should NOT be escaped

inlineToMediaWiki _ (TeX _) = return ""

inlineToMediaWiki _ (HtmlInline str) = return str 

inlineToMediaWiki _ (LineBreak) = return "<br />\n"

inlineToMediaWiki _ Space = return " "

inlineToMediaWiki opts (Link txt (src, _)) = do
  link <- inlineListToMediaWiki opts txt
  let useAuto = txt == [Code src]
  let src' = if isURI src
                then src
                else if take 1 src == "/"
                         then "http://{{SERVERNAME}}" ++ src
                         else "http://{{SERVERNAME}}/" ++ src
  return $ if useAuto
              then src'
              else "[" ++ src' ++ " " ++ link ++ "]"

inlineToMediaWiki opts (Image alt (source, tit)) = do
  alt' <- inlineListToMediaWiki opts alt
  let txt = if (null tit)
               then if null alt
                       then ""
                       else "|" ++ alt'
               else "|" ++ tit
  return $ "[[Image:" ++ source ++ txt ++ "]]"

inlineToMediaWiki opts (Note contents) = do 
  contents' <- blockListToMediaWiki opts contents
  modify (\s -> s { stNotes = True })
  return $ "<ref>" ++ contents' ++ "</ref>"
  -- note - may not work for notes with multiple blocks