aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/Docx/Parse.hs
blob: 7d1171ee3e9b7a47a3c9ff62be6a0bb08d4ec22d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
{-# LANGUAGE PatternGuards #-}

{-
Copyright (C) 2014 Jesse Rosenthal <jrosenthal@jhu.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.Readers.Docx.Parse
 Copyright : Copyright (C) 2014 Jesse Rosenthal
 License : GNU GPL, version 2 or above

 Maintainer : Jesse Rosenthal <jrosenthal@jhu.edu>
 Stability : alpha
 Portability : portable

Conversion of docx archive into Docx haskell type
-}

module Text.Pandoc.Readers.Docx.Parse ( Docx(..)
                                      , Document(..)
                                      , Body(..)
                                      , BodyPart(..)
                                      , TblLook(..)
                                      , ParPart(..)
                                      , Run(..)
                                      , RunElem(..)
                                      , Notes
                                      , Numbering
                                      , Relationship
                                      , Media
                                      , RunStyle(..)
                                      , ParIndentation(..)
                                      , ParagraphStyle(..)
                                      , Row(..)
                                      , Cell(..)
                                      , archiveToDocx
                                      ) where

import Codec.Archive.Zip
import Text.XML.Light
import Data.Maybe
import Data.List
import System.FilePath
import Data.Bits ((.|.))
import qualified Data.ByteString.Lazy as B
import qualified Text.Pandoc.UTF8 as UTF8
import Control.Monad.Reader
import Control.Applicative ((<$>))
import qualified Data.Map as M
import Text.Pandoc.Compat.Except
import Text.TeXMath.Readers.OMML (readOMML)
import Text.Pandoc.Readers.Docx.Fonts (getUnicode, Font(..))
import Text.TeXMath (Exp)
import Data.Char (readLitChar)

data ReaderEnv = ReaderEnv { envNotes         :: Notes
                           , envNumbering     :: Numbering
                           , envRelationships :: [Relationship]
                           , envMedia         :: Media
                           }
               deriving Show

data DocxError = DocxError | WrongElem
               deriving Show

instance Error DocxError where
  noMsg = WrongElem

type D = ExceptT DocxError (Reader ReaderEnv)

runD :: D a -> ReaderEnv -> Either DocxError a
runD dx re = runReader (runExceptT dx ) re

maybeToD :: Maybe a -> D a
maybeToD (Just a) = return a
maybeToD Nothing = throwError DocxError

eitherToD :: Either a b -> D b
eitherToD (Right b) = return b
eitherToD (Left _)  = throwError DocxError

concatMapM        :: (Monad m) => (a -> m [b]) -> [a] -> m [b]
concatMapM f xs   =  liftM concat (mapM f xs)


-- This is similar to `mapMaybe`: it maps a function returning the D
-- monad over a list, and only keeps the non-erroring return values.
mapD :: (a -> D b) -> [a] -> D [b]
mapD f xs =
  let handler x = (f x >>= (\y-> return [y])) `catchError` (\_ -> return [])
  in
   concatMapM handler xs

type NameSpaces = [(String, String)]

data Docx = Docx Document
          deriving Show

data Document = Document NameSpaces Body
          deriving Show

data Body = Body [BodyPart]
          deriving Show

type Media = [(FilePath, B.ByteString)]

data Numbering = Numbering NameSpaces [Numb] [AbstractNumb]
                 deriving Show

data Numb = Numb String String           -- right now, only a key to an abstract num
            deriving Show

data AbstractNumb = AbstractNumb String [Level]
                    deriving Show

-- (ilvl, format, string, start)
type Level = (String, String, String, Maybe Integer)

data Relationship = Relationship (RelId, Target)
                  deriving Show

data Notes = Notes NameSpaces
             (Maybe (M.Map String Element))
             (Maybe (M.Map String Element))
           deriving Show

data ParIndentation = ParIndentation { leftParIndent :: Maybe Integer
                                     , rightParIndent :: Maybe Integer
                                     , hangingParIndent :: Maybe Integer}
                      deriving Show

data ParagraphStyle = ParagraphStyle { pStyle :: [String]
                                     , indentation :: Maybe ParIndentation
                                     }
                      deriving Show

defaultParagraphStyle :: ParagraphStyle
defaultParagraphStyle = ParagraphStyle { pStyle = []
                                       , indentation = Nothing
                                       }


data BodyPart = Paragraph ParagraphStyle [ParPart]
              | ListItem ParagraphStyle String String Level [ParPart]
              | Tbl String TblGrid TblLook [Row]
              | OMathPara [Exp]
              deriving Show

type TblGrid = [Integer]

data TblLook = TblLook {firstRowFormatting::Bool}
              deriving Show

defaultTblLook :: TblLook
defaultTblLook = TblLook{firstRowFormatting = False}

data Row = Row [Cell]
           deriving Show

data Cell = Cell [BodyPart]
            deriving Show

data ParPart = PlainRun Run
             | Insertion ChangeId Author ChangeDate [Run]
             | Deletion ChangeId Author ChangeDate [Run]
             | BookMark BookMarkId Anchor
             | InternalHyperLink Anchor [Run]
             | ExternalHyperLink URL [Run]
             | Drawing FilePath B.ByteString
             | PlainOMath [Exp]
             deriving Show

data Run = Run RunStyle [RunElem]
         | Footnote [BodyPart]
         | Endnote [BodyPart]
         | InlineDrawing FilePath B.ByteString
           deriving Show

data RunElem = TextRun String | LnBrk | Tab
             deriving Show

data RunStyle = RunStyle { isBold :: Bool
                         , isItalic :: Bool
                         , isSmallCaps :: Bool
                         , isStrike :: Bool
                         , isSuperScript :: Bool
                         , isSubScript :: Bool
                         , rUnderline :: Maybe String
                         , rStyle :: Maybe String }
                deriving Show

defaultRunStyle :: RunStyle
defaultRunStyle = RunStyle { isBold = False
                           , isItalic = False
                           , isSmallCaps = False
                           , isStrike = False
                           , isSuperScript = False
                           , isSubScript = False
                           , rUnderline = Nothing
                           , rStyle = Nothing
                           }


type Target = String
type Anchor = String
type URL = String
type BookMarkId = String
type RelId = String
type ChangeId = String
type Author = String
type ChangeDate = String

attrToNSPair :: Attr -> Maybe (String, String)
attrToNSPair (Attr (QName s _ (Just "xmlns")) val) = Just (s, val)
attrToNSPair _ = Nothing

archiveToDocx :: Archive -> Either DocxError Docx
archiveToDocx archive = do
  let notes     = archiveToNotes archive
      numbering = archiveToNumbering archive
      rels      = archiveToRelationships archive
      media     = archiveToMedia archive
      rEnv = ReaderEnv notes numbering rels media
  doc <- runD (archiveToDocument archive) rEnv
  return $ Docx doc


archiveToDocument :: Archive -> D Document
archiveToDocument zf = do
  entry <- maybeToD $ findEntryByPath "word/document.xml" zf
  docElem <- maybeToD $ (parseXMLDoc . UTF8.toStringLazy . fromEntry) entry
  let namespaces = mapMaybe attrToNSPair (elAttribs docElem)
  bodyElem <- maybeToD $ findChild (elemName namespaces "w" "body") docElem
  body <- elemToBody namespaces bodyElem
  return $ Document namespaces body

elemToBody :: NameSpaces -> Element -> D Body
elemToBody ns element | isElem ns "w" "body" element =
  mapD (elemToBodyPart ns) (elChildren element) >>=
  (\bps -> return $ Body bps)
elemToBody _ _ = throwError WrongElem

archiveToNotes :: Archive -> Notes
archiveToNotes zf =
  let fnElem = findEntryByPath "word/footnotes.xml" zf
               >>= (parseXMLDoc . UTF8.toStringLazy . fromEntry)
      enElem = findEntryByPath "word/endnotes.xml" zf
               >>= (parseXMLDoc . UTF8.toStringLazy . fromEntry)
      fn_namespaces = case fnElem of
        Just e -> mapMaybe attrToNSPair (elAttribs e)
        Nothing -> []
      en_namespaces = case enElem of
        Just e -> mapMaybe attrToNSPair (elAttribs e)
        Nothing -> []
      ns = unionBy (\x y -> fst x == fst y) fn_namespaces en_namespaces
      fn = fnElem >>= (elemToNotes ns "footnote")
      en = enElem >>= (elemToNotes ns "endnote")
  in
   Notes ns fn en

filePathIsRel :: FilePath -> Bool
filePathIsRel fp =
  let (dir, name) = splitFileName fp
  in
   (dir == "word/_rels/") && ((takeExtension name) == ".rels")

relElemToRelationship :: Element -> Maybe Relationship
relElemToRelationship element | qName (elName element) == "Relationship" =
  do
    relId <- findAttr (QName "Id" Nothing Nothing) element
    target <- findAttr (QName "Target" Nothing Nothing) element
    return $ Relationship (relId, target)
relElemToRelationship _ = Nothing


archiveToRelationships :: Archive -> [Relationship]
archiveToRelationships archive =
  let relPaths = filter filePathIsRel (filesInArchive archive)
      entries  = mapMaybe (\f -> findEntryByPath f archive) relPaths
      relElems = mapMaybe (parseXMLDoc . UTF8.toStringLazy . fromEntry) entries
      rels =     mapMaybe relElemToRelationship $ concatMap elChildren relElems
  in
   rels

filePathIsMedia :: FilePath -> Bool
filePathIsMedia fp =
  let (dir, _) = splitFileName fp
  in
   (dir == "word/media/")

getMediaPair :: Archive -> FilePath -> Maybe (FilePath, B.ByteString)
getMediaPair zf fp =
  case findEntryByPath fp zf of
    Just e -> Just (fp, fromEntry e)
    Nothing -> Nothing

archiveToMedia :: Archive -> Media
archiveToMedia zf =
  mapMaybe (getMediaPair zf) (filter filePathIsMedia (filesInArchive zf))

lookupLevel :: String -> String -> Numbering -> Maybe Level
lookupLevel numId ilvl (Numbering _ numbs absNumbs) = do
  absNumId <- lookup numId $ map (\(Numb nid absnumid) -> (nid, absnumid)) numbs
  lvls <- lookup absNumId $ map (\(AbstractNumb aid ls) -> (aid, ls)) absNumbs
  lvl  <- lookup ilvl $ map (\l@(i, _, _, _) -> (i, l)) lvls
  return lvl

numElemToNum :: NameSpaces -> Element -> Maybe Numb
numElemToNum ns element |
  qName (elName element) == "num" &&
  qURI (elName element) == (lookup "w" ns) = do
    numId <- findAttr (QName "numId" (lookup "w" ns) (Just "w")) element
    absNumId <- findChild (QName "abstractNumId" (lookup "w" ns) (Just "w")) element
                >>= findAttr (QName "val" (lookup "w" ns) (Just "w"))
    return $ Numb numId absNumId
numElemToNum _ _ = Nothing

absNumElemToAbsNum :: NameSpaces -> Element -> Maybe AbstractNumb
absNumElemToAbsNum ns element |
  qName (elName element) == "abstractNum" &&
  qURI (elName element) == (lookup "w" ns) = do
    absNumId <- findAttr
                (QName "abstractNumId" (lookup "w" ns) (Just "w"))
                element
    let levelElems = findChildren
                 (QName "lvl" (lookup "w" ns) (Just "w"))
                 element
        levels = mapMaybe (levelElemToLevel ns) levelElems
    return $ AbstractNumb absNumId levels
absNumElemToAbsNum _ _ = Nothing

levelElemToLevel :: NameSpaces -> Element -> Maybe Level
levelElemToLevel ns element |
    qName (elName element) == "lvl" &&
    qURI (elName element) == (lookup "w" ns) = do
      ilvl <- findAttr (QName "ilvl" (lookup "w" ns) (Just "w")) element
      fmt <- findChild (QName "numFmt" (lookup "w" ns) (Just "w")) element
             >>= findAttr (QName "val" (lookup "w" ns) (Just "w"))
      txt <- findChild (QName "lvlText" (lookup "w" ns) (Just "w")) element
             >>= findAttr (QName "val" (lookup "w" ns) (Just "w"))
      let start = findChild (QName "start" (lookup "w" ns) (Just "w")) element
                  >>= findAttr (QName "val" (lookup "w" ns) (Just "w"))
                  >>= (\s -> listToMaybe (map fst (reads s :: [(Integer, String)])))
      return (ilvl, fmt, txt, start)
levelElemToLevel _ _ = Nothing

archiveToNumbering' :: Archive -> Maybe Numbering
archiveToNumbering' zf = do
  case findEntryByPath "word/numbering.xml" zf of
    Nothing -> Just $ Numbering [] [] []
    Just entry -> do
      numberingElem <- (parseXMLDoc . UTF8.toStringLazy . fromEntry) entry
      let namespaces = mapMaybe attrToNSPair (elAttribs numberingElem)
          numElems = findChildren
                     (QName "num" (lookup "w" namespaces) (Just "w"))
                     numberingElem
          absNumElems = findChildren
                        (QName "abstractNum" (lookup "w" namespaces) (Just "w"))
                        numberingElem
          nums = mapMaybe (numElemToNum namespaces) numElems
          absNums = mapMaybe (absNumElemToAbsNum namespaces) absNumElems
      return $ Numbering namespaces nums absNums

archiveToNumbering :: Archive -> Numbering
archiveToNumbering archive =
  fromMaybe (Numbering [] [] []) (archiveToNumbering' archive)

elemToNotes :: NameSpaces -> String -> Element -> Maybe (M.Map String Element)
elemToNotes ns notetype element
  | isElem ns "w" (notetype ++ "s") element =
      let pairs = mapMaybe
                  (\e -> findAttr (elemName ns "w" "id") e >>=
                         (\a -> Just (a, e)))
                  (findChildren (elemName ns "w" notetype) element)
      in
       Just $ M.fromList $ pairs
elemToNotes _ _ _ = Nothing

---------------------------------------------
---------------------------------------------

elemName :: NameSpaces -> String -> String -> QName
elemName ns prefix name = (QName name (lookup prefix ns) (Just prefix))

isElem :: NameSpaces -> String -> String -> Element -> Bool
isElem ns prefix name element =
  qName (elName element) == name &&
  qURI (elName element) == (lookup prefix ns)


elemToTblGrid :: NameSpaces -> Element -> D TblGrid
elemToTblGrid ns element | isElem ns "w" "tblGrid" element =
  let cols = findChildren (elemName ns "w" "gridCol") element
  in
   mapD (\e -> maybeToD (findAttr (elemName ns "w" "val") e >>= stringToInteger))
   cols
elemToTblGrid _ _ = throwError WrongElem

elemToTblLook :: NameSpaces -> Element -> D TblLook
elemToTblLook ns element | isElem ns "w" "tblLook" element =
  let firstRow = findAttr (elemName ns "w" "firstRow") element
      val = findAttr (elemName ns "w" "val") element
      firstRowFmt =
        case firstRow of
          Just "1" -> True
          Just  _  -> False
          Nothing -> case val of
            Just bitMask -> testBitMask bitMask 0x020
            Nothing      -> False
  in
   return $ TblLook{firstRowFormatting = firstRowFmt}
elemToTblLook _ _ = throwError WrongElem

elemToRow :: NameSpaces -> Element -> D Row
elemToRow ns element | isElem ns "w" "tr" element =
  do
    let cellElems = findChildren (elemName ns "w" "tc") element
    cells <- mapD (elemToCell ns) cellElems
    return $ Row cells
elemToRow _ _ = throwError WrongElem

elemToCell :: NameSpaces -> Element -> D Cell
elemToCell ns element | isElem ns "w" "tc" element =
  do
    cellContents <- mapD (elemToBodyPart ns) (elChildren element)
    return $ Cell cellContents
elemToCell _ _ = throwError WrongElem

elemToParIndentation :: NameSpaces -> Element -> Maybe ParIndentation
elemToParIndentation ns element | isElem ns "w" "ind" element =
  Just $ ParIndentation {
    leftParIndent =
       findAttr (QName "left" (lookup "w" ns) (Just "w")) element >>=
       stringToInteger
    , rightParIndent =
      findAttr (QName "right" (lookup "w" ns) (Just "w")) element >>=
      stringToInteger
    , hangingParIndent =
      findAttr (QName "hanging" (lookup "w" ns) (Just "w")) element >>=
      stringToInteger}
elemToParIndentation _ _ = Nothing


elemToNumInfo :: NameSpaces -> Element -> Maybe (String, String)
elemToNumInfo ns element  | isElem ns "w" "p" element = do
  let pPr = findChild (elemName ns "w" "pPr") element
      numPr = pPr >>= findChild (elemName ns "w" "numPr")
  lvl <- numPr >>=
         findChild (elemName ns "w" "ilvl") >>=
         findAttr (elemName ns "w" "val")
  numId <- numPr >>=
           findChild (elemName ns "w" "numId") >>=
           findAttr (elemName ns "w" "val")
  return (numId, lvl)
elemToNumInfo _ _ = Nothing

testBitMask :: String -> Int -> Bool
testBitMask bitMaskS n =
  case (reads ("0x" ++ bitMaskS) :: [(Int, String)]) of
    []            -> False
    ((n', _) : _) -> ((n' .|. n) /= 0)

stringToInteger :: String -> Maybe Integer
stringToInteger s = listToMaybe $ map fst (reads s :: [(Integer, String)])

elemToBodyPart :: NameSpaces -> Element -> D BodyPart
elemToBodyPart ns element
  | isElem ns "w" "p" element
  , (c:_) <- findChildren (elemName ns "m" "oMathPara") element =
      do
        expsLst <- eitherToD $ readOMML $ showElement c
        return $ OMathPara expsLst
elemToBodyPart ns element
  | isElem ns "w" "p" element
  , Just (numId, lvl) <- elemToNumInfo ns element = do
    let parstyle = elemToParagraphStyle ns element
    parparts <- mapD (elemToParPart ns) (elChildren element)
    num <- asks envNumbering
    case lookupLevel numId lvl num of
      Just levelInfo -> return $ ListItem parstyle numId lvl levelInfo parparts
      Nothing         -> throwError WrongElem
elemToBodyPart ns element
  | isElem ns "w" "p" element = do
    let parstyle = elemToParagraphStyle ns element
    parparts <- mapD (elemToParPart ns) (elChildren element)
    return $ Paragraph parstyle parparts
elemToBodyPart ns element
  | isElem ns "w" "tbl" element = do
    let caption' = findChild (elemName ns "w" "tblPr") element
                   >>= findChild (elemName ns "w" "tblCaption")
                   >>= findAttr (elemName ns "w" "val")
        caption = (fromMaybe "" caption')
        grid' = case findChild (elemName ns "w" "tblGrid") element of
          Just g -> elemToTblGrid ns g
          Nothing -> return []
        tblLook' = case findChild (elemName ns "w" "tblPr") element >>=
                          findChild (elemName ns "w" "tblLook")
                     of
                       Just l -> elemToTblLook ns l
                       Nothing -> return defaultTblLook

    grid <- grid'
    tblLook <- tblLook'
    rows <- mapD (elemToRow ns) (elChildren element)
    return $ Tbl caption grid tblLook rows
elemToBodyPart _ _ = throwError WrongElem

lookupRelationship :: RelId -> [Relationship] -> Maybe Target
lookupRelationship relid rels =
  lookup relid (map (\(Relationship pair) -> pair) rels)

expandDrawingId :: String -> D (FilePath, B.ByteString)
expandDrawingId s = do
  target <- asks (lookupRelationship s . envRelationships)
  case target of
    Just filepath -> do
      bytes <- asks (lookup (combine "word" filepath) . envMedia)
      case bytes of
        Just bs -> return (filepath, bs)
        Nothing -> throwError DocxError
    Nothing -> throwError DocxError

elemToParPart :: NameSpaces -> Element -> D ParPart
elemToParPart ns element
  | isElem ns "w" "r" element
  , Just _ <- findChild (elemName ns "w" "drawing") element =
    let a_ns = "http://schemas.openxmlformats.org/drawingml/2006/main"
        drawing = findElement (QName "blip" (Just a_ns) (Just "a")) element
                  >>= findAttr (QName "embed" (lookup "r" ns) (Just "r"))
    in
     case drawing of
       Just s -> expandDrawingId s >>= (\(fp, bs) -> return $ Drawing fp bs)
       Nothing -> throwError WrongElem
elemToParPart ns element
  | isElem ns "w" "r" element =
    elemToRun ns element >>= (\r -> return $ PlainRun r)
elemToParPart ns element
  | isElem ns "w" "ins" element
  , Just cId <- findAttr (elemName ns "w" "id") element
  , Just cAuthor <- findAttr (elemName ns "w" "author") element
  , Just cDate <- findAttr (elemName ns "w" "date") element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    return $ Insertion cId cAuthor cDate runs
elemToParPart ns element
  | isElem ns "w" "del" element
  , Just cId <- findAttr (elemName ns "w" "id") element
  , Just cAuthor <- findAttr (elemName ns "w" "author") element
  , Just cDate <- findAttr (elemName ns "w" "date") element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    return $ Deletion cId cAuthor cDate runs
elemToParPart ns element
  | isElem ns "w" "bookmarkStart" element
  , Just bmId <- findAttr (elemName ns "w" "id") element
  , Just bmName <- findAttr (elemName ns "w" "name") element =
    return $ BookMark bmId bmName
elemToParPart ns element
  | isElem ns "w" "hyperlink" element
  , Just anchor <- findAttr (elemName ns "w" "anchor") element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    return $ InternalHyperLink anchor runs
elemToParPart ns element
  | isElem ns "w" "hyperlink" element
  , Just relId <- findAttr (elemName ns "r" "id") element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    rels <- asks envRelationships
    return $ case lookupRelationship relId rels of
      Just target -> ExternalHyperLink target runs
      Nothing     -> ExternalHyperLink "" runs
elemToParPart ns element
  | isElem ns "m" "oMath" element =
    (eitherToD $ readOMML $ showElement element) >>= (return . PlainOMath)
elemToParPart _ _ = throwError WrongElem

lookupFootnote :: String -> Notes -> Maybe Element
lookupFootnote s (Notes _ fns _) = fns >>= (M.lookup s)

lookupEndnote :: String -> Notes -> Maybe Element
lookupEndnote s (Notes _ _ ens) = ens >>= (M.lookup s)

elemToRun :: NameSpaces -> Element -> D Run
elemToRun ns element
  | isElem ns "w" "r" element
  , Just drawingElem <- findChild (elemName ns "w" "drawing") element =
    let a_ns = "http://schemas.openxmlformats.org/drawingml/2006/main"
        drawing = findElement (QName "blip" (Just a_ns) (Just "a")) drawingElem
                  >>= findAttr (QName "embed" (lookup "r" ns) (Just "r"))
    in
     case drawing of
       Just s -> expandDrawingId s >>=
                 (\(fp, bs) -> return $ InlineDrawing fp bs)
       Nothing -> throwError WrongElem
elemToRun ns element
  | isElem ns "w" "r" element
  , Just ref <- findChild (elemName ns "w" "footnoteReference") element
  , Just fnId <- findAttr (elemName ns "w" "id") ref = do
    notes <- asks envNotes
    case lookupFootnote fnId notes of
      Just e -> do bps <- mapD (elemToBodyPart ns) (elChildren e)
                   return $ Footnote bps
      Nothing  -> return $ Footnote []
elemToRun ns element
  | isElem ns "w" "r" element
  , Just ref <- findChild (elemName ns "w" "endnoteReference") element
  , Just enId <- findAttr (elemName ns "w" "id") ref = do
    notes <- asks envNotes
    case lookupEndnote enId notes of
      Just e -> do bps <- mapD (elemToBodyPart ns) (elChildren e)
                   return $ Endnote bps
      Nothing  -> return $ Endnote []
elemToRun ns element
  | isElem ns "w" "r" element = do
    runElems <- elemToRunElems ns element
    return $ Run (elemToRunStyle ns element) runElems
elemToRun _ _ = throwError WrongElem

elemToParagraphStyle :: NameSpaces -> Element -> ParagraphStyle
elemToParagraphStyle ns element
  | Just pPr <- findChild (elemName ns "w" "pPr") element =
    ParagraphStyle
      {pStyle =
          mapMaybe
          (findAttr (elemName ns "w" "val"))
          (findChildren (elemName ns "w" "pStyle") pPr)
      , indentation =
            findChild (elemName ns "w" "ind") pPr >>=
            elemToParIndentation ns
      }
elemToParagraphStyle _ _ =  defaultParagraphStyle


elemToRunStyle :: NameSpaces -> Element -> RunStyle
elemToRunStyle ns element
  | Just rPr <- findChild (elemName ns "w" "rPr") element =
    RunStyle
      {
        isBold = isJust $ findChild (QName "b" (lookup "w" ns) (Just "w")) rPr
      , isItalic = isJust $ findChild (QName "i" (lookup "w" ns) (Just "w")) rPr
      , isSmallCaps = isJust $ findChild (QName "smallCaps" (lookup "w" ns) (Just "w")) rPr
      , isStrike = isJust $ findChild (QName "strike" (lookup "w" ns) (Just "w")) rPr
      , isSuperScript =
        (Just "superscript" ==
        (findChild (QName "vertAlign" (lookup "w" ns) (Just "w")) rPr >>=
         findAttr (QName "val" (lookup "w" ns) (Just "w"))))
      , isSubScript =
        (Just "subscript" ==
        (findChild (QName "vertAlign" (lookup "w" ns) (Just "w")) rPr >>=
         findAttr (QName "val" (lookup "w" ns) (Just "w"))))
      , rUnderline =
        findChild (QName "u" (lookup "w" ns) (Just "w")) rPr >>=
        findAttr (QName "val" (lookup "w" ns) (Just "w"))
      , rStyle =
        findChild (QName "rStyle" (lookup "w" ns) (Just "w")) rPr >>=
        findAttr (QName "val" (lookup "w" ns) (Just "w"))
        }
elemToRunStyle _ _ = defaultRunStyle

elemToRunElem :: NameSpaces -> Element -> D RunElem
elemToRunElem ns element
  | isElem ns "w" "t" element
    || isElem ns "w" "delText" element
    || isElem ns "m" "t" element =
    return $ TextRun $ strContent element
  | isElem ns "w" "br" element = return LnBrk
  | isElem ns "w" "tab" element = return Tab
  | isElem ns "w" "sym" element = return (getSymChar ns element)
  | otherwise = throwError WrongElem

-- The char attribute is a hex string
getSymChar :: NameSpaces -> Element -> RunElem
getSymChar ns element
  | Just s <- lowerFromPrivate <$> getCodepoint
  , Just font <- getFont =
  let [(char, _)] = readLitChar ("\\x" ++ s) in
    TextRun . maybe "" (:[]) $ getUnicode font char
  where
    getCodepoint = findAttr (elemName ns "w" "char") element
    getFont = stringToFont =<< findAttr (elemName ns "w" "font") element
    lowerFromPrivate ('F':xs) = '0':xs
    lowerFromPrivate xs = xs
getSymChar _ _ = TextRun ""

stringToFont :: String -> Maybe Font
stringToFont "Symbol" = Just Symbol
stringToFont _ = Nothing

elemToRunElems :: NameSpaces -> Element -> D [RunElem]
elemToRunElems ns element
  |  isElem ns "w" "r" element
     || isElem ns "m" "r" element =
       mapD (elemToRunElem ns) (elChildren element)
elemToRunElems _ _ = throwError WrongElem