{-# LANGUAGE ScopedTypeVariables, PatternGuards #-}
{-
Copyright (C) 2012-2014 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.Docx
   Copyright   : Copyright (C) 2012-2014 John MacFarlane
   License     : GNU GPL, version 2 or above

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

Conversion of 'Pandoc' documents to docx.
-}
module Text.Pandoc.Writers.Docx ( writeDocx ) where
import Data.List ( intercalate, isPrefixOf, isSuffixOf, stripPrefix )
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL
import qualified Data.ByteString.Lazy.Char8 as BL8
import qualified Data.Map as M
import qualified Text.Pandoc.UTF8 as UTF8
import Text.Pandoc.Compat.Monoid ((<>))
import Codec.Archive.Zip
import Data.Time.Clock.POSIX
import Data.Time.Clock
import Data.Time.Format
import System.Environment
import Text.Pandoc.Compat.Locale (defaultTimeLocale)
import Text.Pandoc.Definition
import Text.Pandoc.Generic
import Text.Pandoc.ImageSize
import Text.Pandoc.Shared hiding (Element)
import Text.Pandoc.Writers.Shared (fixDisplayMath)
import Text.Pandoc.Options
import Text.Pandoc.Readers.TeXMath
import Text.Pandoc.Highlighting ( highlight )
import Text.Pandoc.Walk
import Text.Highlighting.Kate.Types ()
import Text.XML.Light as XML
import Text.TeXMath
import Control.Monad.State
import Text.Highlighting.Kate
import Data.Unique (hashUnique, newUnique)
import System.Random (randomRIO)
import Text.Printf (printf)
import qualified Control.Exception as E
import Text.Pandoc.MIME (MimeType, getMimeType, getMimeTypeDef,
                         extensionFromMimeType)
import Control.Applicative ((<$>), (<|>), (<*>))
import Data.Maybe (fromMaybe, mapMaybe)
import Data.Char (isDigit)

data ListMarker = NoMarker
                | BulletMarker
                | NumberMarker ListNumberStyle ListNumberDelim Int
                deriving (Show, Read, Eq, Ord)

listMarkerToId :: ListMarker -> String
listMarkerToId NoMarker = "990"
listMarkerToId BulletMarker = "991"
listMarkerToId (NumberMarker sty delim n) =
  '9' : '9' : styNum : delimNum : show n
  where styNum = case sty of
                      DefaultStyle   -> '2'
                      Example        -> '3'
                      Decimal        -> '4'
                      LowerRoman     -> '5'
                      UpperRoman     -> '6'
                      LowerAlpha     -> '7'
                      UpperAlpha     -> '8'
        delimNum = case delim of
                      DefaultDelim   -> '0'
                      Period         -> '1'
                      OneParen       -> '2'
                      TwoParens      -> '3'

data WriterState = WriterState{
         stTextProperties :: [Element]
       , stParaProperties :: [Element]
       , stFootnotes      :: [Element]
       , stSectionIds     :: [String]
       , stExternalLinks  :: M.Map String String
       , stImages         :: M.Map FilePath (String, String, Maybe MimeType, Element, B.ByteString)
       , stListLevel      :: Int
       , stListNumId      :: Int
       , stLists          :: [ListMarker]
       , stInsId          :: Int
       , stDelId          :: Int
       , stInDel          :: Bool
       , stChangesAuthor  :: String
       , stChangesDate    :: String
       , stPrintWidth     :: Integer
       , stHeadingStyles  :: [(Int,String)]
       }

defaultWriterState :: WriterState
defaultWriterState = WriterState{
        stTextProperties = []
      , stParaProperties = []
      , stFootnotes      = []
      , stSectionIds     = []
      , stExternalLinks  = M.empty
      , stImages         = M.empty
      , stListLevel      = -1
      , stListNumId      = 1
      , stLists          = [NoMarker]
      , stInsId          = 1
      , stDelId          = 1
      , stInDel          = False
      , stChangesAuthor  = "unknown"
      , stChangesDate    = "1969-12-31T19:00:00Z"
      , stPrintWidth     = 1
      , stHeadingStyles  = []
      }

type WS a = StateT WriterState IO a

mknode :: Node t => String -> [(String,String)] -> t -> Element
mknode s attrs =
  add_attrs (map (\(k,v) -> Attr (nodename k) v) attrs) .  node (nodename s)

nodename :: String -> QName
nodename s = QName{ qName = name, qURI = Nothing, qPrefix = prefix }
 where (name, prefix) = case break (==':') s of
                             (xs,[])    -> (xs, Nothing)
                             (ys, _:zs) -> (zs, Just ys)

toLazy :: B.ByteString -> BL.ByteString
toLazy = BL.fromChunks . (:[])

renderXml :: Element -> BL.ByteString
renderXml elt = BL8.pack "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" <>
  UTF8.fromStringLazy (showElement elt)

renumIdMap :: Int -> [Element] -> M.Map String String
renumIdMap _ [] = M.empty
renumIdMap n (e:es)
  | Just oldId <- findAttr (QName "Id" Nothing Nothing) e =
      M.insert oldId ("rId" ++ (show n)) (renumIdMap (n+1) es)
  | otherwise = renumIdMap n es

replaceAttr :: (QName -> Bool) -> String -> [XML.Attr] -> [XML.Attr]
replaceAttr _ _ [] = []
replaceAttr f val (a:as) | f (attrKey a) =
                             (XML.Attr (attrKey a) val) : (replaceAttr f val as)
                         | otherwise = a : (replaceAttr f val as)

renumId :: (QName -> Bool) -> (M.Map String String) -> Element -> Element
renumId f renumMap e
  | Just oldId <- findAttrBy f e
  , Just newId <- M.lookup oldId renumMap =
    let attrs' = replaceAttr f newId (elAttribs e)
    in
     e { elAttribs = attrs' }
  | otherwise = e

renumIds :: (QName -> Bool) -> (M.Map String String) -> [Element] -> [Element]
renumIds f renumMap = map (renumId f renumMap)

-- | Produce an Docx file from a Pandoc document.
writeDocx :: WriterOptions  -- ^ Writer options
          -> Pandoc         -- ^ Document to convert
          -> IO BL.ByteString
writeDocx opts doc@(Pandoc meta _) = do
  let datadir = writerUserDataDir opts
  let doc' = walk fixDisplayMath doc
  username <- lookup "USERNAME" <$> getEnvironment
  utctime <- getCurrentTime
  refArchive <- liftM (toArchive . toLazy) $
       case writerReferenceDocx opts of
             Just f  -> B.readFile f
             Nothing -> readDataFile datadir "reference.docx"
  distArchive <- liftM (toArchive . toLazy) $ readDataFile datadir "reference.docx"

  parsedDoc <- parseXml refArchive distArchive "word/document.xml"
  let wname f qn = qPrefix qn == Just "w" && f (qName qn)
  let mbsectpr = filterElementName (wname (=="sectPr")) parsedDoc

  -- Gets the template size
  let mbpgsz = mbsectpr >>= (filterElementName (wname (=="pgSz")))
  let mbAttrSzWidth = (elAttribs <$> mbpgsz) >>= (lookupAttrBy ((=="w") . qName))

  let mbpgmar = mbsectpr >>= (filterElementName (wname (=="pgMar")))
  let mbAttrMarLeft = (elAttribs <$> mbpgmar) >>= (lookupAttrBy ((=="left") . qName))
  let mbAttrMarRight = (elAttribs <$> mbpgmar) >>= (lookupAttrBy ((=="right") . qName))

  -- Get the avaible area (converting the size and the margins to int and
  -- doing the difference
  let pgContentWidth = (-) <$> (read <$> mbAttrSzWidth ::Maybe Integer)
                       <*> (
                         (+) <$> (read <$> mbAttrMarRight ::Maybe Integer)
                         <*> (read <$> mbAttrMarLeft ::Maybe Integer)
                       )

  -- styles
  let stylepath = "word/styles.xml"
  styledoc <- parseXml refArchive distArchive stylepath

  -- parse styledoc for heading styles
  let styleNamespaces = map ((,) <$> qName . attrKey <*> attrVal) .
                        filter ((==Just "xmlns") . qPrefix . attrKey) .
                        elAttribs $ styledoc
  let headingStyles =
       let
           mywURI = lookup "w" styleNamespaces
           myName name = QName name mywURI (Just "w")
           getAttrStyleId = findAttr (myName "styleId")
           getNameVal = findChild (myName "name") >=> findAttr (myName "val")
           getNum s | not $ null s, all isDigit s = Just (read s :: Int)
                    | otherwise = Nothing
           getEngHeader = getAttrStyleId >=> stripPrefix "Heading" >=> getNum
           getIntHeader = getNameVal >=> stripPrefix "heading " >=> getNum
           toTuple getF = liftM2 (,) <$> getF <*> getAttrStyleId
           toMap getF = mapMaybe (toTuple getF) $
                        findChildren (myName "style") styledoc
           select a b | not $ null a = a
                      | otherwise = b
           in
              select (toMap getEngHeader) (toMap getIntHeader)

  ((contents, footnotes), st) <- runStateT (writeOpenXML opts{writerWrapText = False} doc')
                       defaultWriterState{ stChangesAuthor = fromMaybe "unknown" username
                                         , stChangesDate   = formatTime defaultTimeLocale "%FT%XZ" utctime
                                         , stPrintWidth = (maybe 420 (\x -> quot x 20) pgContentWidth)
                                         , stHeadingStyles = headingStyles}
  let epochtime = floor $ utcTimeToPOSIXSeconds utctime
  let imgs = M.elems $ stImages st

  -- create entries for images in word/media/...
  let toImageEntry (_,path,_,_,img) = toEntry ("word/" ++ path) epochtime $ toLazy img
  let imageEntries = map toImageEntry imgs

  let stdAttributes =
            [("xmlns:w","http://schemas.openxmlformats.org/wordprocessingml/2006/main")
            ,("xmlns:m","http://schemas.openxmlformats.org/officeDocument/2006/math")
            ,("xmlns:r","http://schemas.openxmlformats.org/officeDocument/2006/relationships")
            ,("xmlns:o","urn:schemas-microsoft-com:office:office")
            ,("xmlns:v","urn:schemas-microsoft-com:vml")
            ,("xmlns:w10","urn:schemas-microsoft-com:office:word")
            ,("xmlns:a","http://schemas.openxmlformats.org/drawingml/2006/main")
            ,("xmlns:pic","http://schemas.openxmlformats.org/drawingml/2006/picture")
            ,("xmlns:wp","http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing")]


  parsedRels <- parseXml refArchive distArchive "word/_rels/document.xml.rels"
  let isHeaderNode e = findAttr (QName "Type" Nothing Nothing) e == Just "http://schemas.openxmlformats.org/officeDocument/2006/relationships/header"
  let isFooterNode e = findAttr (QName "Type" Nothing Nothing) e == Just "http://schemas.openxmlformats.org/officeDocument/2006/relationships/footer"
  let headers = filterElements isHeaderNode parsedRels
  let footers = filterElements isFooterNode parsedRels

  let extractTarget = findAttr (QName "Target" Nothing Nothing)

  -- we create [Content_Types].xml and word/_rels/document.xml.rels
  -- from scratch rather than reading from reference.docx,
  -- because Word sometimes changes these files when a reference.docx is modified,
  -- e.g. deleting the reference to footnotes.xml or removing default entries
  -- for image content types.

  -- [Content_Types].xml
  let mkOverrideNode (part', contentType') = mknode "Override"
               [("PartName",part'),("ContentType",contentType')] ()
  let mkImageOverride (_, imgpath, mbMimeType, _, _) =
          mkOverrideNode ("/word/" ++ imgpath,
                          fromMaybe "application/octet-stream" mbMimeType)
  let mkMediaOverride imgpath =
          mkOverrideNode ('/':imgpath, getMimeTypeDef imgpath)
  let overrides = map mkOverrideNode (
                  [("/word/webSettings.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.webSettings+xml")
                  ,("/word/numbering.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.numbering+xml")
                  ,("/word/settings.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.settings+xml")
                  ,("/word/theme/theme1.xml",
                    "application/vnd.openxmlformats-officedocument.theme+xml")
                  ,("/word/fontTable.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.fontTable+xml")
                  ,("/docProps/app.xml",
                    "application/vnd.openxmlformats-officedocument.extended-properties+xml")
                  ,("/docProps/core.xml",
                    "application/vnd.openxmlformats-package.core-properties+xml")
                  ,("/word/styles.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.styles+xml")
                  ,("/word/document.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml")
                  ,("/word/footnotes.xml",
                    "application/vnd.openxmlformats-officedocument.wordprocessingml.footnotes+xml")
                  ] ++
                  map (\x -> (maybe "" ("/word/" ++) $ extractTarget x,
                       "application/vnd.openxmlformats-officedocument.wordprocessingml.header+xml")) headers ++
                  map (\x -> (maybe "" ("/word/" ++) $ extractTarget x,
                       "application/vnd.openxmlformats-officedocument.wordprocessingml.footer+xml")) footers) ++
                    map mkImageOverride imgs ++
                    map mkMediaOverride [ eRelativePath e | e <- zEntries refArchive
                                        , "word/media/" `isPrefixOf` eRelativePath e ]

  let defaultnodes = [mknode "Default"
              [("Extension","xml"),("ContentType","application/xml")] (),
             mknode "Default"
              [("Extension","rels"),("ContentType","application/vnd.openxmlformats-package.relationships+xml")] ()]
  let contentTypesDoc = mknode "Types" [("xmlns","http://schemas.openxmlformats.org/package/2006/content-types")] $ defaultnodes ++ overrides
  let contentTypesEntry = toEntry "[Content_Types].xml" epochtime
        $ renderXml contentTypesDoc

  -- word/_rels/document.xml.rels
  let toBaseRel (url', id', target') = mknode "Relationship"
                                          [("Type",url')
                                          ,("Id",id')
                                          ,("Target",target')] ()
  let baserels' = map toBaseRel
                    [("http://schemas.openxmlformats.org/officeDocument/2006/relationships/numbering",
                      "rId1",
                      "numbering.xml")
                    ,("http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles",
                      "rId2",
                      "styles.xml")
                    ,("http://schemas.openxmlformats.org/officeDocument/2006/relationships/settings",
                      "rId3",
                      "settings.xml")
                    ,("http://schemas.openxmlformats.org/officeDocument/2006/relationships/webSettings",
                      "rId4",
                      "webSettings.xml")
                    ,("http://schemas.openxmlformats.org/officeDocument/2006/relationships/fontTable",
                      "rId5",
                      "fontTable.xml")
                    ,("http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme",
                      "rId6",
                      "theme/theme1.xml")
                    ,("http://schemas.openxmlformats.org/officeDocument/2006/relationships/footnotes",
                      "rId7",
                      "footnotes.xml")
                    ]

  let idMap = renumIdMap (length baserels' + 1) (headers ++ footers)
  let renumHeaders = renumIds (\q -> qName q == "Id") idMap headers
  let renumFooters = renumIds (\q -> qName q == "Id") idMap footers
  let baserels = baserels' ++ renumHeaders ++ renumFooters
  let toImgRel (ident,path,_,_,_) =  mknode "Relationship" [("Type","http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"),("Id",ident),("Target",path)] ()
  let imgrels = map toImgRel imgs
  let toLinkRel (src,ident) =  mknode "Relationship" [("Type","http://schemas.openxmlformats.org/officeDocument/2006/relationships/hyperlink"),("Id",ident),("Target",src),("TargetMode","External") ] ()
  let linkrels = map toLinkRel $ M.toList $ stExternalLinks st
  let reldoc = mknode "Relationships" [("xmlns","http://schemas.openxmlformats.org/package/2006/relationships")] $ baserels ++ imgrels ++ linkrels
  let relEntry = toEntry "word/_rels/document.xml.rels" epochtime
        $ renderXml reldoc


  -- adjust contents to add sectPr from reference.docx
  let sectpr = case mbsectpr of
        Just sectpr' -> let cs = renumIds
                                 (\q -> qName q == "id" && qPrefix q == Just "r")
                                 idMap
                                 (elChildren sectpr')
                        in
                         add_attrs (elAttribs sectpr') $ mknode "w:sectPr" [] cs
        Nothing      -> (mknode "w:sectPr" [] ())

  -- let sectpr = fromMaybe (mknode "w:sectPr" [] ()) mbsectpr'
  let contents' = contents ++ [sectpr]
  let docContents = mknode "w:document" stdAttributes
                    $ mknode "w:body" [] contents'



  -- word/document.xml
  let contentEntry = toEntry "word/document.xml" epochtime
                     $ renderXml docContents

  -- footnotes
  let notes = mknode "w:footnotes" stdAttributes footnotes
  let footnotesEntry = toEntry "word/footnotes.xml" epochtime $ renderXml notes

  -- footnote rels
  let footnoteRelEntry = toEntry "word/_rels/footnotes.xml.rels" epochtime
        $ renderXml $ mknode "Relationships" [("xmlns","http://schemas.openxmlformats.org/package/2006/relationships")]
        linkrels

  -- styles
  let newstyles = styleToOpenXml $ writerHighlightStyle opts
  let styledoc' = styledoc{ elContent = elContent styledoc ++
                  [Elem x | x <- newstyles, writerHighlight opts] }
  let styleEntry = toEntry stylepath epochtime $ renderXml styledoc'

  -- construct word/numbering.xml
  let numpath = "word/numbering.xml"
  numbering <- parseXml refArchive distArchive numpath
  newNumElts <- mkNumbering (stLists st)
  let allElts = onlyElems (elContent numbering) ++ newNumElts
  let numEntry = toEntry numpath epochtime $ renderXml numbering{ elContent =
                       -- we want all the abstractNums first, then the nums,
                       -- otherwise things break:
                       [Elem e | e <- allElts
                               , qName (elName e) == "abstractNum" ] ++
                       [Elem e | e <- allElts
                               , qName (elName e) == "num" ] }
  let docPropsPath = "docProps/core.xml"
  let docProps = mknode "cp:coreProperties"
          [("xmlns:cp","http://schemas.openxmlformats.org/package/2006/metadata/core-properties")
          ,("xmlns:dc","http://purl.org/dc/elements/1.1/")
          ,("xmlns:dcterms","http://purl.org/dc/terms/")
          ,("xmlns:dcmitype","http://purl.org/dc/dcmitype/")
          ,("xmlns:xsi","http://www.w3.org/2001/XMLSchema-instance")]
          $ mknode "dc:title" [] (stringify $ docTitle meta)
          : mknode "dc:creator" [] (intercalate "; " (map stringify $ docAuthors meta))
          : maybe []
             (\x -> [ mknode "dcterms:created" [("xsi:type","dcterms:W3CDTF")] x
                    , mknode "dcterms:modified" [("xsi:type","dcterms:W3CDTF")] x
                    ]) (normalizeDate $ stringify $ docDate meta)
  let docPropsEntry = toEntry docPropsPath epochtime $ renderXml docProps

  let relsPath = "_rels/.rels"
  let rels = mknode "Relationships" [("xmlns", "http://schemas.openxmlformats.org/package/2006/relationships")]
        $ map (\attrs -> mknode "Relationship" attrs ())
        [ [("Id","rId1")
          ,("Type","http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument")
          ,("Target","word/document.xml")]
        , [("Id","rId4")
          ,("Type","http://schemas.openxmlformats.org/officeDocument/2006/relationships/extended-properties")
          ,("Target","docProps/app.xml")]
        , [("Id","rId3")
          ,("Type","http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties")
          ,("Target","docProps/core.xml")]
        ]
  let relsEntry = toEntry relsPath epochtime $ renderXml rels

  let entryFromArchive arch path =
         maybe (fail $ path ++ " corrupt or missing in reference docx")
               return
               (findEntryByPath path arch `mplus` findEntryByPath path distArchive)
  docPropsAppEntry <- entryFromArchive refArchive "docProps/app.xml"
  themeEntry <- entryFromArchive refArchive "word/theme/theme1.xml"
  fontTableEntry <- entryFromArchive refArchive "word/fontTable.xml"
  -- we use dist archive for settings.xml, because Word sometimes
  -- adds references to footnotes or endnotes we don't have...
  settingsEntry <- entryFromArchive distArchive "word/settings.xml"
  webSettingsEntry <- entryFromArchive refArchive "word/webSettings.xml"
  headerFooterEntries <- mapM (entryFromArchive refArchive) $
                     mapMaybe (fmap ("word/" ++) . extractTarget)
                     (headers ++ footers)
  let miscRelEntries = [ e | e <- zEntries refArchive
                       , "word/_rels/" `isPrefixOf` (eRelativePath e)
                       , ".xml.rels" `isSuffixOf` (eRelativePath e)
                       , eRelativePath e /= "word/_rels/document.xml.rels"
                       , eRelativePath e /= "word/_rels/footnotes.xml.rels" ]
  let otherMediaEntries = [ e | e <- zEntries refArchive
                          , "word/media/" `isPrefixOf` eRelativePath e ]

  -- Create archive
  let archive = foldr addEntryToArchive emptyArchive $
                  contentTypesEntry : relsEntry : contentEntry : relEntry :
                  footnoteRelEntry : numEntry : styleEntry : footnotesEntry :
                  docPropsEntry : docPropsAppEntry : themeEntry :
                  fontTableEntry : settingsEntry : webSettingsEntry :
                  imageEntries ++ headerFooterEntries ++
                  miscRelEntries ++ otherMediaEntries
  return $ fromArchive archive

styleToOpenXml :: Style -> [Element]
styleToOpenXml style = parStyle : map toStyle alltoktypes
  where alltoktypes = enumFromTo KeywordTok NormalTok
        toStyle toktype = mknode "w:style" [("w:type","character"),
                           ("w:customStyle","1"),("w:styleId",show toktype)]
                             [ mknode "w:name" [("w:val",show toktype)] ()
                             , mknode "w:basedOn" [("w:val","VerbatimChar")] ()
                             , mknode "w:rPr" [] $
                               [ mknode "w:color" [("w:val",tokCol toktype)] ()
                                 | tokCol toktype /= "auto" ] ++
                               [ mknode "w:shd" [("w:val","clear"),("w:fill",tokBg toktype)] ()
                                 | tokBg toktype /= "auto" ] ++
                               [ mknode "w:b" [] () | tokFeature tokenBold toktype ] ++
                               [ mknode "w:i" [] () | tokFeature tokenItalic toktype ] ++
                               [ mknode "w:u" [] () | tokFeature tokenUnderline toktype ]
                             ]
        tokStyles = tokenStyles style
        tokFeature f toktype = maybe False f $ lookup toktype tokStyles
        tokCol toktype = maybe "auto" (drop 1 . fromColor)
                         $ (tokenColor =<< lookup toktype tokStyles)
                           `mplus` defaultColor style
        tokBg toktype = maybe "auto" (drop 1 . fromColor)
                         $ (tokenBackground =<< lookup toktype tokStyles)
                           `mplus` backgroundColor style
        parStyle = mknode "w:style" [("w:type","paragraph"),
                           ("w:customStyle","1"),("w:styleId","SourceCode")]
                             [ mknode "w:name" [("w:val","Source Code")] ()
                             , mknode "w:basedOn" [("w:val","Normal")] ()
                             , mknode "w:link" [("w:val","VerbatimChar")] ()
                             , mknode "w:pPr" []
                               $ mknode "w:wordWrap" [("w:val","off")] ()
                               : ( maybe [] (\col -> [mknode "w:shd" [("w:val","clear"),("w:fill",drop 1 $ fromColor col)] ()])
                                 $ backgroundColor style )
                             ]

-- this is the lowest number used for a list numId
baseListId :: Int
baseListId = 1000

mkNumbering :: [ListMarker] -> IO [Element]
mkNumbering lists = do
  elts <- mapM mkAbstractNum (ordNub lists)
  return $ elts ++ zipWith mkNum lists [baseListId..(baseListId + length lists - 1)]

mkNum :: ListMarker -> Int -> Element
mkNum marker numid =
  mknode "w:num" [("w:numId",show numid)]
   $ mknode "w:abstractNumId" [("w:val",listMarkerToId marker)] ()
   : case marker of
       NoMarker     -> []
       BulletMarker -> []
       NumberMarker _ _ start ->
          map (\lvl -> mknode "w:lvlOverride" [("w:ilvl",show (lvl :: Int))]
              $ mknode "w:startOverride" [("w:val",show start)] ()) [0..6]

mkAbstractNum :: ListMarker -> IO Element
mkAbstractNum marker = do
  nsid <- randomRIO (0x10000000 :: Integer, 0xFFFFFFFF :: Integer)
  return $ mknode "w:abstractNum" [("w:abstractNumId",listMarkerToId marker)]
    $ mknode "w:nsid" [("w:val", printf "%8x" nsid)] ()
    : mknode "w:multiLevelType" [("w:val","multilevel")] ()
    : map (mkLvl marker) [0..6]

mkLvl :: ListMarker -> Int -> Element
mkLvl marker lvl =
  mknode "w:lvl" [("w:ilvl",show lvl)] $
    [ mknode "w:start" [("w:val",start)] ()
      | marker /= NoMarker && marker /= BulletMarker ] ++
    [ mknode "w:numFmt" [("w:val",fmt)] ()
    , mknode "w:lvlText" [("w:val",lvltxt)] ()
    , mknode "w:lvlJc" [("w:val","left")] ()
    , mknode "w:pPr" []
      [ mknode "w:tabs" []
        $ mknode "w:tab" [("w:val","num"),("w:pos",show $ lvl * step)] ()
      , mknode "w:ind" [("w:left",show $ lvl * step + hang),("w:hanging",show hang)] ()
      ]
    ]
    where (fmt, lvltxt, start) =
            case marker of
                 NoMarker             -> ("bullet"," ","1")
                 BulletMarker         -> ("bullet",bulletFor lvl,"1")
                 NumberMarker st de n -> (styleFor st lvl
                                         ,patternFor de ("%" ++ show (lvl + 1))
                                         ,show n)
          step = 720
          hang = 480
          bulletFor 0 = "\x2022"  -- filled circle
          bulletFor 1 = "\x2013"  -- en dash
          bulletFor 2 = "\x2022"  -- hyphen bullet
          bulletFor 3 = "\x2013"
          bulletFor 4 = "\x2022"
          bulletFor 5 = "\x2013"
          bulletFor _ = "\x2022"
          styleFor UpperAlpha _ = "upperLetter"
          styleFor LowerAlpha _ = "lowerLetter"
          styleFor UpperRoman _ = "upperRoman"
          styleFor LowerRoman _ = "lowerRoman"
          styleFor Decimal _ = "decimal"
          styleFor DefaultStyle 1 = "decimal"
          styleFor DefaultStyle 2 = "lowerLetter"
          styleFor DefaultStyle 3 = "lowerRoman"
          styleFor DefaultStyle 4 = "decimal"
          styleFor DefaultStyle 5 = "lowerLetter"
          styleFor DefaultStyle 6 = "lowerRoman"
          styleFor _ _ = "decimal"
          patternFor OneParen s = s ++ ")"
          patternFor TwoParens s = "(" ++ s ++ ")"
          patternFor _ s = s ++ "."

getNumId :: WS Int
getNumId = (((baseListId - 1) +) . length) `fmap` gets stLists

-- | Convert Pandoc document to two lists of
-- OpenXML elements (the main document and footnotes).
writeOpenXML :: WriterOptions -> Pandoc -> WS ([Element], [Element])
writeOpenXML opts (Pandoc meta blocks) = do
  let tit = docTitle meta ++ case lookupMeta "subtitle" meta of
                                  Just (MetaBlocks [Plain xs]) -> LineBreak : xs
                                  _ -> []
  let auths = docAuthors meta
  let dat = docDate meta
  let abstract' = case lookupMeta "abstract" meta of
                       Just (MetaBlocks bs) -> bs
                       Just (MetaInlines ils) -> [Plain ils]
                       _ -> []
  let subtitle' = case lookupMeta "subtitle" meta of
                       Just (MetaBlocks [Plain xs]) -> xs
                       Just (MetaBlocks [Para  xs]) -> xs
                       Just (MetaInlines xs)        -> xs
                       _ -> []
  title <- withParaProp (pStyle "Title") $ blocksToOpenXML opts [Para tit | not (null tit)]
  subtitle <- withParaProp (pStyle "Subtitle") $ blocksToOpenXML opts [Para subtitle' | not (null subtitle')]
  authors <- withParaProp (pStyle "Author") $ blocksToOpenXML opts $
       map Para auths
  date <- withParaProp (pStyle "Date") $ blocksToOpenXML opts [Para dat | not (null dat)]
  abstract <- if null abstract'
                 then return []
                 else withParaProp (pStyle "Abstract") $ blocksToOpenXML opts abstract'
  let convertSpace (Str x : Space : Str y : xs) = Str (x ++ " " ++ y) : xs
      convertSpace (Str x : Str y : xs) = Str (x ++ y) : xs
      convertSpace xs = xs
  let blocks' = bottomUp convertSpace blocks
  doc' <- blocksToOpenXML opts blocks'
  notes' <- reverse `fmap` gets stFootnotes
  let meta' = title ++ subtitle ++ authors ++ date ++ abstract
  return (meta' ++ doc', notes')

-- | Convert a list of Pandoc blocks to OpenXML.
blocksToOpenXML :: WriterOptions -> [Block] -> WS [Element]
blocksToOpenXML opts bls = concat `fmap` mapM (blockToOpenXML opts) bls

pStyle :: String -> Element
pStyle sty = mknode "w:pStyle" [("w:val",sty)] ()

rStyle :: String -> Element
rStyle sty = mknode "w:rStyle" [("w:val",sty)] ()

getUniqueId :: MonadIO m => m String
-- the + 20 is to ensure that there are no clashes with the rIds
-- already in word/document.xml.rel
getUniqueId = liftIO $ (show . (+ 20) . hashUnique) `fmap` newUnique

-- | Convert a Pandoc block element to OpenXML.
blockToOpenXML :: WriterOptions -> Block -> WS [Element]
blockToOpenXML _ Null = return []
blockToOpenXML opts (Div (_,["references"],_) bs) = do
  let (hs, bs') = span isHeaderBlock bs
  header <- blocksToOpenXML opts hs
  -- We put the Bibliography style on paragraphs after the header
  rest <- withParaProp (pStyle "Bibliography") $ blocksToOpenXML opts bs'
  return (header ++ rest)
blockToOpenXML opts (Div _ bs) = blocksToOpenXML opts bs
blockToOpenXML opts (Header lev (ident,_,_) lst) = do
  headingStyles <- gets stHeadingStyles
  paraProps <- maybe id (withParaProp . pStyle) (lookup lev headingStyles) $
                    getParaProps False
  contents <- inlinesToOpenXML opts lst
  usedIdents <- gets stSectionIds
  let bookmarkName = if null ident
                        then uniqueIdent lst usedIdents
                        else ident
  modify $ \s -> s{ stSectionIds = bookmarkName : stSectionIds s }
  id' <- getUniqueId
  let bookmarkStart = mknode "w:bookmarkStart" [("w:id", id')
                                               ,("w:name",bookmarkName)] ()
  let bookmarkEnd = mknode "w:bookmarkEnd" [("w:id", id')] ()
  return [mknode "w:p" [] (paraProps ++ [bookmarkStart, bookmarkEnd] ++ contents)]
blockToOpenXML opts (Plain lst) = withParaProp (pStyle "Compact")
  $ blockToOpenXML opts (Para lst)
-- title beginning with fig: indicates that the image is a figure
blockToOpenXML opts (Para [Image alt (src,'f':'i':'g':':':tit)]) = do
  paraProps <- getParaProps False
  contents <- inlinesToOpenXML opts [Image alt (src,tit)]
  captionNode <- withParaProp (pStyle "ImageCaption")
                 $ blockToOpenXML opts (Para alt)
  return $ mknode "w:p" [] (paraProps ++ contents) : captionNode
-- fixDisplayMath sometimes produces a Para [] as artifact
blockToOpenXML _ (Para []) = return []
blockToOpenXML opts (Para lst) = do
    paraProps <- getParaProps $ case lst of
                                     [Math DisplayMath _] -> True
                                     _                    -> False
    contents <- inlinesToOpenXML opts lst
    return [mknode "w:p" [] (paraProps ++ contents)]
blockToOpenXML _ (RawBlock format str)
  | format == Format "openxml" = return [ x | Elem x <- parseXML str ]
  | otherwise                  = return []
blockToOpenXML opts (BlockQuote blocks) =
  withParaProp (pStyle "BlockQuote") $ blocksToOpenXML opts blocks
blockToOpenXML opts (CodeBlock attrs str) =
  withParaProp (pStyle "SourceCode") $ blockToOpenXML opts $ Para [Code attrs str]
blockToOpenXML _ HorizontalRule = return [
  mknode "w:p" [] $ mknode "w:r" [] $ mknode "w:pict" []
    $ mknode "v:rect" [("style","width:0;height:1.5pt"),
                       ("o:hralign","center"),
                       ("o:hrstd","t"),("o:hr","t")] () ]
blockToOpenXML opts (Table caption aligns widths headers rows) = do
  let captionStr = stringify caption
  caption' <- if null caption
                 then return []
                 else withParaProp (pStyle "TableCaption")
                      $ blockToOpenXML opts (Para caption)
  let alignmentFor al = mknode "w:jc" [("w:val",alignmentToString al)] ()
  let cellToOpenXML (al, cell) = withParaProp (alignmentFor al)
                                    $ blocksToOpenXML opts cell
  headers' <- mapM cellToOpenXML $ zip aligns headers
  rows' <- mapM (mapM cellToOpenXML . zip aligns) rows
  let borderProps = mknode "w:tcPr" []
                    [ mknode "w:tcBorders" []
                      $ mknode "w:bottom" [("w:val","single")] ()
                    , mknode "w:vAlign" [("w:val","bottom")] () ]
  let emptyCell = [mknode "w:p" [] [mknode "w:pPr" []
                    [mknode "w:pStyle" [("w:val","Compact")] ()]]]
  let mkcell border contents = mknode "w:tc" []
                            $ [ borderProps | border ] ++
                            if null contents
                               then emptyCell
                               else contents
  let mkrow border cells = mknode "w:tr" [] $ map (mkcell border) cells
  let textwidth = 7920  -- 5.5 in in twips, 1/20 pt
  let fullrow = 5000 -- 100% specified in pct
  let rowwidth = fullrow * sum widths
  let mkgridcol w = mknode "w:gridCol"
                       [("w:w", show (floor (textwidth * w) :: Integer))] ()
  return $
    caption' ++
    [mknode "w:tbl" []
      ( mknode "w:tblPr" []
        (   mknode "w:tblStyle" [("w:val","TableNormal")] () :
            mknode "w:tblW" [("w:type", "pct"), ("w:w", show rowwidth)] () :
          [ mknode "w:tblCaption" [("w:val", captionStr)] ()
          | not (null caption) ] )
      : mknode "w:tblGrid" []
        (if all (==0) widths
            then []
            else map mkgridcol widths)
      : [ mkrow True headers' | not (all null headers) ] ++
      map (mkrow False) rows'
      )]
blockToOpenXML opts (BulletList lst) = do
  let marker = BulletMarker
  addList marker
  numid  <- getNumId
  asList $ concat `fmap` mapM (listItemToOpenXML opts numid) lst
blockToOpenXML opts (OrderedList (start, numstyle, numdelim) lst) = do
  let marker = NumberMarker numstyle numdelim start
  addList marker
  numid  <- getNumId
  asList $ concat `fmap` mapM (listItemToOpenXML opts numid) lst
blockToOpenXML opts (DefinitionList items) =
  concat `fmap` mapM (definitionListItemToOpenXML opts) items

definitionListItemToOpenXML  :: WriterOptions -> ([Inline],[[Block]]) -> WS [Element]
definitionListItemToOpenXML opts (term,defs) = do
  term' <- withParaProp (pStyle "DefinitionTerm")
           $ blockToOpenXML opts (Para term)
  defs' <- withParaProp (pStyle "Definition")
           $ concat `fmap` mapM (blocksToOpenXML opts) defs
  return $ term' ++ defs'

addList :: ListMarker -> WS ()
addList marker = do
  lists <- gets stLists
  modify $ \st -> st{ stLists = lists ++ [marker] }

listItemToOpenXML :: WriterOptions -> Int -> [Block] -> WS [Element]
listItemToOpenXML _ _ []                   = return []
listItemToOpenXML opts numid (first:rest) = do
  first' <- withNumId numid $ blockToOpenXML opts first
  -- baseListId is the code for no list marker:
  rest'  <- withNumId baseListId $ blocksToOpenXML opts rest
  return $ first' ++ rest'

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

-- | Convert a list of inline elements to OpenXML.
inlinesToOpenXML :: WriterOptions -> [Inline] -> WS [Element]
inlinesToOpenXML opts lst = concat `fmap` mapM (inlineToOpenXML opts) lst

withNumId :: Int -> WS a -> WS a
withNumId numid p = do
  origNumId <- gets stListNumId
  modify $ \st -> st{ stListNumId = numid }
  result <- p
  modify $ \st -> st{ stListNumId = origNumId }
  return result

asList :: WS a -> WS a
asList p = do
  origListLevel <- gets stListLevel
  modify $ \st -> st{ stListLevel = stListLevel st + 1 }
  result <- p
  modify $ \st -> st{ stListLevel = origListLevel }
  return result

getTextProps :: WS [Element]
getTextProps = do
  props <- gets stTextProperties
  return $ if null props
              then []
              else [mknode "w:rPr" [] props]

pushTextProp :: Element -> WS ()
pushTextProp d = modify $ \s -> s{ stTextProperties = d : stTextProperties s }

popTextProp :: WS ()
popTextProp = modify $ \s -> s{ stTextProperties = drop 1 $ stTextProperties s }

withTextProp :: Element -> WS a -> WS a
withTextProp d p = do
  pushTextProp d
  res <- p
  popTextProp
  return res

getParaProps :: Bool -> WS [Element]
getParaProps displayMathPara = do
  props <- gets stParaProperties
  listLevel <- gets stListLevel
  numid <- gets stListNumId
  let listPr = if listLevel >= 0 && not displayMathPara
                  then [ mknode "w:numPr" []
                         [ mknode "w:numId" [("w:val",show numid)] ()
                         , mknode "w:ilvl" [("w:val",show listLevel)] () ]
                       ]
                  else []
  return $ case props ++ listPr of
                [] -> []
                ps -> [mknode "w:pPr" [] ps]

pushParaProp :: Element -> WS ()
pushParaProp d = modify $ \s -> s{ stParaProperties = d : stParaProperties s }

popParaProp :: WS ()
popParaProp = modify $ \s -> s{ stParaProperties = drop 1 $ stParaProperties s }

withParaProp :: Element -> WS a -> WS a
withParaProp d p = do
  pushParaProp d
  res <- p
  popParaProp
  return res

formattedString :: String -> WS [Element]
formattedString str = do
  props <- getTextProps
  inDel <- gets stInDel
  return [ mknode "w:r" [] $
             props ++
             [ mknode (if inDel then "w:delText" else "w:t")
               [("xml:space","preserve")] str ] ]

-- | Convert an inline element to OpenXML.
inlineToOpenXML :: WriterOptions -> Inline -> WS [Element]
inlineToOpenXML _ (Str str) = formattedString str
inlineToOpenXML opts Space = inlineToOpenXML opts (Str " ")
inlineToOpenXML opts (Span (_,classes,kvs) ils)
  | "insertion" `elem` classes = do
    defaultAuthor <- gets stChangesAuthor
    defaultDate <- gets stChangesDate
    let author = fromMaybe defaultAuthor (lookup "author" kvs)
        date   = fromMaybe defaultDate (lookup "date" kvs)
    insId <- gets stInsId
    modify $ \s -> s{stInsId = (insId + 1)}
    x <- inlinesToOpenXML opts ils
    return [ mknode "w:ins" [("w:id", (show insId)),
                             ("w:author", author),
                             ("w:date", date)]
             x ]
  | "deletion" `elem` classes = do
    defaultAuthor <- gets stChangesAuthor
    defaultDate <- gets stChangesDate
    let author = fromMaybe defaultAuthor (lookup "author" kvs)
        date   = fromMaybe defaultDate (lookup "date" kvs)
    delId <- gets stDelId
    modify $ \s -> s{stDelId = (delId + 1)}
    modify $ \s -> s{stInDel = True}
    x <- inlinesToOpenXML opts ils
    modify $ \s -> s{stInDel = False}
    return [ mknode "w:del" [("w:id", (show delId)),
                             ("w:author", author),
                             ("w:date", date)]
             x ]
  | otherwise = do
    let off x = withTextProp (mknode x [("w:val","0")] ())
    ((if "csl-no-emph" `elem` classes then off "w:i" else id) .
     (if "csl-no-strong" `elem` classes then off "w:b" else id) .
     (if "csl-no-smallcaps" `elem` classes then off "w:smallCaps" else id))
      $ inlinesToOpenXML opts ils
inlineToOpenXML opts (Strong lst) =
  withTextProp (mknode "w:b" [] ()) $ inlinesToOpenXML opts lst
inlineToOpenXML opts (Emph lst) =
  withTextProp (mknode "w:i" [] ()) $ inlinesToOpenXML opts lst
inlineToOpenXML opts (Subscript lst) =
  withTextProp (mknode "w:vertAlign" [("w:val","subscript")] ())
  $ inlinesToOpenXML opts lst
inlineToOpenXML opts (Superscript lst) =
  withTextProp (mknode "w:vertAlign" [("w:val","superscript")] ())
  $ inlinesToOpenXML opts lst
inlineToOpenXML opts (SmallCaps lst) =
  withTextProp (mknode "w:smallCaps" [] ())
  $ inlinesToOpenXML opts lst
inlineToOpenXML opts (Strikeout lst) =
  withTextProp (mknode "w:strike" [] ())
  $ inlinesToOpenXML opts lst
inlineToOpenXML _ LineBreak = return [br]
inlineToOpenXML _ (RawInline f str)
  | f == Format "openxml" = return [ x | Elem x <- parseXML str ]
  | otherwise            = return []
inlineToOpenXML opts (Quoted quoteType lst) =
  inlinesToOpenXML opts $ [Str open] ++ lst ++ [Str close]
    where (open, close) = case quoteType of
                            SingleQuote -> ("\x2018", "\x2019")
                            DoubleQuote -> ("\x201C", "\x201D")
inlineToOpenXML opts (Math mathType str) = do
  let displayType = if mathType == DisplayMath
                       then DisplayBlock
                       else DisplayInline
  case writeOMML displayType <$> readTeX str of
        Right r -> return [r]
        Left  _ -> inlinesToOpenXML opts (texMathToInlines mathType str)
inlineToOpenXML opts (Cite _ lst) = inlinesToOpenXML opts lst
inlineToOpenXML opts (Code attrs str) =
  withTextProp (rStyle "VerbatimChar")
  $ if writerHighlight opts
       then case highlight formatOpenXML attrs str of
             Nothing  -> unhighlighted
             Just h   -> return h
       else unhighlighted
     where unhighlighted = intercalate [br] `fmap`
                             (mapM formattedString $ lines str)
           formatOpenXML _fmtOpts = intercalate [br] . map (map toHlTok)
           toHlTok (toktype,tok) = mknode "w:r" []
                                     [ mknode "w:rPr" []
                                       [ rStyle $ show toktype ]
                                     , mknode "w:t" [("xml:space","preserve")] tok ]
inlineToOpenXML opts (Note bs) = do
  notes <- gets stFootnotes
  notenum <- getUniqueId
  let notemarker = mknode "w:r" []
                   [ mknode "w:rPr" [] (rStyle "FootnoteRef")
                   , mknode "w:footnoteRef" [] () ]
  let notemarkerXml = RawInline (Format "openxml") $ ppElement notemarker
  let insertNoteRef (Plain ils : xs) = Plain (notemarkerXml : ils) : xs
      insertNoteRef (Para ils  : xs) = Para  (notemarkerXml : ils) : xs
      insertNoteRef xs               = Para [notemarkerXml] : xs
  oldListLevel <- gets stListLevel
  oldParaProperties <- gets stParaProperties
  oldTextProperties <- gets stTextProperties
  modify $ \st -> st{ stListLevel = -1, stParaProperties = [], stTextProperties = [] }
  contents <- withParaProp (pStyle "FootnoteText") $ blocksToOpenXML opts
                $ insertNoteRef bs
  modify $ \st -> st{ stListLevel = oldListLevel, stParaProperties = oldParaProperties,
                      stTextProperties = oldTextProperties }
  let newnote = mknode "w:footnote" [("w:id", notenum)] $ contents
  modify $ \s -> s{ stFootnotes = newnote : notes }
  return [ mknode "w:r" []
           [ mknode "w:rPr" [] (rStyle "FootnoteRef")
           , mknode "w:footnoteReference" [("w:id", notenum)] () ] ]
-- internal link:
inlineToOpenXML opts (Link txt ('#':xs,_)) = do
  contents <- withTextProp (rStyle "Link") $ inlinesToOpenXML opts txt
  return [ mknode "w:hyperlink" [("w:anchor",xs)] contents ]
-- external link:
inlineToOpenXML opts (Link txt (src,_)) = do
  contents <- withTextProp (rStyle "Link") $ inlinesToOpenXML opts txt
  extlinks <- gets stExternalLinks
  id' <- case M.lookup src extlinks of
            Just i   -> return i
            Nothing  -> do
              i <- ("rId"++) `fmap` getUniqueId
              modify $ \st -> st{ stExternalLinks =
                        M.insert src i extlinks }
              return i
  return [ mknode "w:hyperlink" [("r:id",id')] contents ]
inlineToOpenXML opts (Image alt (src, tit)) = do
  -- first, check to see if we've already done this image
  pageWidth <- gets stPrintWidth
  imgs <- gets stImages
  case M.lookup src imgs of
    Just (_,_,_,elt,_) -> return [elt]
    Nothing -> do
      res <- liftIO $
               fetchItem' (writerMediaBag opts) (writerSourceURL opts) src
      case res of
        Left (_ :: E.SomeException) -> do
          liftIO $ warn $ "Could not find image `" ++ src ++ "', skipping..."
          -- emit alt text
          inlinesToOpenXML opts alt
        Right (img, mt) -> do
          ident <- ("rId"++) `fmap` getUniqueId
          let size = imageSize img
          let (xpt,ypt) = maybe (120,120) sizeInPoints size
          -- 12700 emu = 1 pt
          let (xemu,yemu) = fitToPage (xpt * 12700, ypt * 12700) (pageWidth * 12700)
          let cNvPicPr = mknode "pic:cNvPicPr" [] $
                           mknode "a:picLocks" [("noChangeArrowheads","1"),("noChangeAspect","1")] ()
          let nvPicPr  = mknode "pic:nvPicPr" []
                          [ mknode "pic:cNvPr"
                              [("descr",src),("id","0"),("name","Picture")] ()
                          , cNvPicPr ]
          let blipFill = mknode "pic:blipFill" []
                           [ mknode "a:blip" [("r:embed",ident)] ()
                           , mknode "a:stretch" [] $ mknode "a:fillRect" [] () ]
          let xfrm =    mknode "a:xfrm" []
                          [ mknode "a:off" [("x","0"),("y","0")] ()
                          , mknode "a:ext" [("cx",show xemu),("cy",show yemu)] () ]
          let prstGeom = mknode "a:prstGeom" [("prst","rect")] $
                           mknode "a:avLst" [] ()
          let ln =      mknode "a:ln" [("w","9525")]
                          [ mknode "a:noFill" [] ()
                          , mknode "a:headEnd" [] ()
                          , mknode "a:tailEnd" [] () ]
          let spPr =    mknode "pic:spPr" [("bwMode","auto")]
                          [xfrm, prstGeom, mknode "a:noFill" [] (), ln]
          let graphic = mknode "a:graphic" [] $
                          mknode "a:graphicData" [("uri","http://schemas.openxmlformats.org/drawingml/2006/picture")]
                            [ mknode "pic:pic" []
                              [ nvPicPr
                              , blipFill
                              , spPr ] ]
          let imgElt = mknode "w:r" [] $
               mknode "w:drawing" [] $
                 mknode "wp:inline" []
                  [ mknode "wp:extent" [("cx",show xemu),("cy",show yemu)] ()
                  , mknode "wp:effectExtent" [("b","0"),("l","0"),("r","0"),("t","0")] ()
                  , mknode "wp:docPr" [("descr",tit),("id","1"),("name","Picture")] ()
                  , graphic ]
          let imgext = case mt >>= extensionFromMimeType of
                            Just x    -> '.':x
                            Nothing   -> case imageType img of
                                              Just Png  -> ".png"
                                              Just Jpeg -> ".jpeg"
                                              Just Gif  -> ".gif"
                                              Just Pdf  -> ".pdf"
                                              Just Eps  -> ".eps"
                                              Nothing   -> ""
          if null imgext
             then -- without an extension there is no rule for content type
               inlinesToOpenXML opts alt -- return alt to avoid corrupted docx
             else do
               let imgpath = "media/" ++ ident ++ imgext
               let mbMimeType = mt <|> getMimeType imgpath
               -- insert mime type to use in constructing [Content_Types].xml
               modify $ \st -> st{ stImages =
                   M.insert src (ident, imgpath, mbMimeType, imgElt, img)
                           $ stImages st }
               return [imgElt]

br :: Element
br = mknode "w:r" [] [mknode "w:br" [("w:type","textWrapping")] () ]

parseXml :: Archive -> Archive -> String -> IO Element
parseXml refArchive distArchive relpath =
  case ((findEntryByPath relpath refArchive `mplus`
         findEntryByPath relpath distArchive)
         >>= parseXMLDoc . UTF8.toStringLazy . fromEntry) of
            Just d  -> return d
            Nothing -> fail $ relpath ++ " corrupt or missing in reference docx"

-- | Scales the image to fit the page
-- sizes are passed in emu
fitToPage :: (Integer, Integer) -> Integer -> (Integer, Integer)
fitToPage (x, y) pageWidth
  -- Fixes width to the page width and scales the height
  | x > pageWidth =
    (pageWidth, round $
      ((fromIntegral pageWidth) / ((fromIntegral :: Integer -> Double) x)) * (fromIntegral y))
  | otherwise = (x, y)