aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/Docx/Parse.hs
blob: 071f901b6f13aa0f1fcee2c69b7241539088cb76 (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
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE PatternGuards     #-}
{-# LANGUAGE ViewPatterns      #-}

{-
Copyright (C) 2014-2017 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) 2014-2017 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(..)
                                      , Extent
                                      , ParPart(..)
                                      , Run(..)
                                      , RunElem(..)
                                      , Notes
                                      , Numbering
                                      , Relationship
                                      , Media
                                      , RunStyle(..)
                                      , VertAlign(..)
                                      , ParIndentation(..)
                                      , ParagraphStyle(..)
                                      , Row(..)
                                      , Cell(..)
                                      , archiveToDocx
                                      , archiveToDocxWithWarnings
                                      ) where
import Codec.Archive.Zip
import Control.Applicative ((<|>))
import Control.Monad.Except
import Control.Monad.Reader
import Control.Monad.State.Strict
import Data.Bits ((.|.))
import qualified Data.ByteString.Lazy as B
import Data.Char (chr, ord, readLitChar)
import Data.List
import qualified Data.Map as M
import Data.Maybe
import System.FilePath
import Text.Pandoc.Readers.Docx.Util
import Text.Pandoc.Shared (filteredFilesFromArchive, safeRead)
import qualified Text.Pandoc.UTF8 as UTF8
import Text.TeXMath (Exp)
import Text.TeXMath.Readers.OMML (readOMML)
import Text.TeXMath.Unicode.Fonts (Font (..), getUnicode, stringToFont)
import Text.XML.Light
import qualified Text.XML.Light.Cursor as XMLC

data ReaderEnv = ReaderEnv { envNotes         :: Notes
                           , envComments      :: Comments
                           , envNumbering     :: Numbering
                           , envRelationships :: [Relationship]
                           , envMedia         :: Media
                           , envFont          :: Maybe Font
                           , envCharStyles    :: CharStyleMap
                           , envParStyles     :: ParStyleMap
                           , envLocation      :: DocumentLocation
                           }
               deriving Show

data ReaderState = ReaderState { stateWarnings :: [String] }
                 deriving Show

data DocxError = DocxError | WrongElem
               deriving Show

type D = ExceptT DocxError (ReaderT ReaderEnv (State ReaderState))

runD :: D a -> ReaderEnv -> ReaderState -> (Either DocxError a, ReaderState)
runD dx re rs = runState (runReaderT (runExceptT dx) re) rs

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

unwrapSDT :: NameSpaces -> Content -> [Content]
unwrapSDT ns (Elem element)
  | isElem ns "w" "sdt" element
  , Just sdtContent <- findChildByName ns "w" "sdtContent" element
  = map Elem $ elChildren sdtContent
unwrapSDT _ content = [content]

unwrapSDTchild :: NameSpaces -> Content -> Content
unwrapSDTchild ns (Elem element) =
  Elem $ element { elContent = concatMap (unwrapSDT ns) (elContent element) }
unwrapSDTchild _ content = content

walkDocument' :: NameSpaces -> XMLC.Cursor -> XMLC.Cursor
walkDocument' ns cur =
  let modifiedCur = XMLC.modifyContent (unwrapSDTchild ns) cur
  in
    case XMLC.nextDF modifiedCur of
      Just cur' -> walkDocument' ns cur'
      Nothing   -> XMLC.root modifiedCur

walkDocument :: NameSpaces -> Element -> Maybe Element
walkDocument ns element =
  let cur = XMLC.fromContent (Elem element)
      cur' = walkDocument' ns cur
  in
    case XMLC.toTree cur' of
      Elem element' -> Just element'
      _             -> Nothing


data Docx = Docx Document
          deriving Show

data Document = Document NameSpaces Body
          deriving Show

data Body = Body [BodyPart]
          deriving Show

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

type CharStyle = (String, RunStyle)

type ParStyle = (String, ParStyleData)

type CharStyleMap = M.Map String RunStyle

type ParStyleMap = M.Map String ParStyleData

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 DocumentLocation = InDocument | InFootnote | InEndnote
                      deriving (Eq,Show)

data Relationship = Relationship DocumentLocation RelId Target
                  deriving Show

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

data Comments = Comments NameSpaces (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
                                     , dropCap     :: Bool
                                     , pHeading    :: Maybe (String, Int)
                                     , pNumInfo    :: Maybe (String, String)
                                     , pBlockQuote :: Maybe Bool
                                     }
                      deriving Show

defaultParagraphStyle :: ParagraphStyle
defaultParagraphStyle = ParagraphStyle { pStyle = []
                                       , indentation = Nothing
                                       , dropCap     = False
                                       , pHeading    = Nothing
                                       , pNumInfo    = Nothing
                                       , pBlockQuote = Nothing
                                       }


data BodyPart = Paragraph ParagraphStyle [ParPart]
              | ListItem ParagraphStyle String String (Maybe 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

-- (width, height) in EMUs
type Extent = Maybe (Double, Double)

data ParPart = PlainRun Run
             | Insertion ChangeId Author ChangeDate [Run]
             | Deletion ChangeId Author ChangeDate [Run]
             | CommentStart CommentId Author CommentDate [BodyPart]
             | CommentEnd CommentId
             | BookMark BookMarkId Anchor
             | InternalHyperLink Anchor [Run]
             | ExternalHyperLink URL [Run]
             | Drawing FilePath String String B.ByteString Extent -- title, alt
             | Chart                                              -- placeholder for now
             | PlainOMath [Exp]
             | SmartTag [Run]
             deriving Show

data Run = Run RunStyle [RunElem]
         | Footnote [BodyPart]
         | Endnote [BodyPart]
         | InlineDrawing FilePath String String B.ByteString Extent -- title, alt
         | InlineChart          -- placeholder
           deriving Show

data RunElem = TextRun String | LnBrk | Tab | SoftHyphen | NoBreakHyphen
             deriving Show

data VertAlign = BaseLn | SupScrpt | SubScrpt
               deriving Show

data RunStyle = RunStyle { isBold      :: Maybe Bool
                         , isItalic    :: Maybe Bool
                         , isSmallCaps :: Maybe Bool
                         , isStrike    :: Maybe Bool
                         , rVertAlign  :: Maybe VertAlign
                         , rUnderline  :: Maybe String
                         , rStyle      :: Maybe CharStyle}
                deriving Show

data ParStyleData = ParStyleData { headingLev   :: Maybe (String, Int)
                                 , isBlockQuote :: Maybe Bool
                                 , numInfo      :: Maybe (String, String)
                                 , psStyle      :: Maybe ParStyle}
                    deriving Show

defaultRunStyle :: RunStyle
defaultRunStyle = RunStyle { isBold = Nothing
                           , isItalic = Nothing
                           , isSmallCaps = Nothing
                           , isStrike = Nothing
                           , rVertAlign = Nothing
                           , rUnderline = Nothing
                           , rStyle = Nothing}

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

archiveToDocx :: Archive -> Either DocxError Docx
archiveToDocx archive = fst <$> archiveToDocxWithWarnings archive

archiveToDocxWithWarnings :: Archive -> Either DocxError (Docx, [String])
archiveToDocxWithWarnings archive = do
  let notes     = archiveToNotes archive
      comments  = archiveToComments archive
      numbering = archiveToNumbering archive
      rels      = archiveToRelationships archive
      media     = filteredFilesFromArchive archive filePathIsMedia
      (styles, parstyles) = archiveToStyles archive
      rEnv =
        ReaderEnv notes comments numbering rels media Nothing styles parstyles InDocument
      rState = ReaderState { stateWarnings = [] }
      (eitherDoc, st) = runD (archiveToDocument archive) rEnv rState
  case eitherDoc of
    Right doc -> Right (Docx doc, stateWarnings st)
    Left e    -> Left e



archiveToDocument :: Archive -> D Document
archiveToDocument zf = do
  entry <- maybeToD $ findEntryByPath "word/document.xml" zf
  docElem <- maybeToD $ (parseXMLDoc . UTF8.toStringLazy . fromEntry) entry
  let namespaces = elemToNameSpaces docElem
  bodyElem <- maybeToD $ findChildByName namespaces "w" "body" docElem
  let bodyElem' = case walkDocument namespaces bodyElem of
        Just e -> e
        Nothing -> bodyElem
  body <- elemToBody namespaces bodyElem'
  return $ Document namespaces body

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

archiveToStyles :: Archive -> (CharStyleMap, ParStyleMap)
archiveToStyles zf =
  let stylesElem = findEntryByPath "word/styles.xml" zf >>=
                   (parseXMLDoc . UTF8.toStringLazy . fromEntry)
  in
   case stylesElem of
     Nothing -> (M.empty, M.empty)
     Just styElem ->
       let namespaces = elemToNameSpaces styElem
       in
        ( M.fromList $ buildBasedOnList namespaces styElem
            (Nothing :: Maybe CharStyle),
          M.fromList $ buildBasedOnList namespaces styElem
            (Nothing :: Maybe ParStyle) )

isBasedOnStyle :: (ElemToStyle a) => NameSpaces -> Element -> Maybe a -> Bool
isBasedOnStyle ns element parentStyle
  | isElem ns "w" "style" element
  , Just styleType <- findAttrByName ns "w" "type" element
  , styleType == cStyleType parentStyle
  , Just basedOnVal <- findChildByName ns "w" "basedOn" element >>=
                       findAttrByName ns "w" "val"
  , Just ps <- parentStyle = basedOnVal == getStyleId ps
  | isElem ns "w" "style" element
  , Just styleType <- findAttrByName ns "w" "type" element
  , styleType == cStyleType parentStyle
  , Nothing <- findChildByName ns "w" "basedOn" element
  , Nothing <- parentStyle = True
  | otherwise = False

class ElemToStyle a where
  cStyleType  :: Maybe a -> String
  elemToStyle :: NameSpaces -> Element -> Maybe a -> Maybe a
  getStyleId     :: a -> String

instance ElemToStyle CharStyle where
  cStyleType _ = "character"
  elemToStyle ns element parentStyle
    | isElem ns "w" "style" element
    , Just "character" <- findAttrByName ns "w" "type" element
    , Just styleId <- findAttrByName ns "w" "styleId" element =
      Just (styleId, elemToRunStyle ns element parentStyle)
    | otherwise = Nothing
  getStyleId s = fst s

instance ElemToStyle ParStyle where
  cStyleType _ = "paragraph"
  elemToStyle ns element parentStyle
    | isElem ns "w" "style" element
    , Just "paragraph" <- findAttrByName ns "w" "type" element
    , Just styleId <- findAttrByName ns "w" "styleId" element =
      Just (styleId, elemToParStyleData ns element parentStyle)
    | otherwise = Nothing
  getStyleId s = fst s

getStyleChildren :: (ElemToStyle a) => NameSpaces -> Element -> Maybe a -> [a]
getStyleChildren ns element parentStyle
  | isElem ns "w" "styles" element =
    mapMaybe (\e -> elemToStyle ns e parentStyle) $
    filterChildren (\e' -> isBasedOnStyle ns e' parentStyle) element
  | otherwise = []

buildBasedOnList :: (ElemToStyle a) => NameSpaces -> Element -> Maybe a -> [a]
buildBasedOnList ns element rootStyle =
  case getStyleChildren ns element rootStyle of
    [] -> []
    stys -> stys ++
            concatMap (buildBasedOnList ns element . Just) stys

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  -> elemToNameSpaces e
        Nothing -> []
      en_namespaces = case enElem of
        Just e  -> elemToNameSpaces 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

archiveToComments :: Archive -> Comments
archiveToComments zf =
  let cmtsElem = findEntryByPath "word/comments.xml" zf
               >>= (parseXMLDoc . UTF8.toStringLazy . fromEntry)
      cmts_namespaces = case cmtsElem of
        Just e  -> elemToNameSpaces e
        Nothing -> []
      cmts = elemToComments cmts_namespaces <$> cmtsElem
  in
    case cmts of
      Just c  -> Comments cmts_namespaces c
      Nothing -> Comments cmts_namespaces M.empty

filePathToRelType :: FilePath -> Maybe DocumentLocation
filePathToRelType "word/_rels/document.xml.rels"  = Just InDocument
filePathToRelType "word/_rels/footnotes.xml.rels" = Just InFootnote
filePathToRelType "word/_rels/endnotes.xml.rels"  = Just InEndnote
filePathToRelType _                               = Nothing

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

filePathToRelationships :: Archive -> FilePath -> [Relationship]
filePathToRelationships ar fp | Just relType <- filePathToRelType fp
                              , Just entry <- findEntryByPath fp ar
                              , Just relElems <- (parseXMLDoc . UTF8.toStringLazy . fromEntry) entry =
  mapMaybe (relElemToRelationship relType) $ elChildren relElems
filePathToRelationships _ _ = []

archiveToRelationships :: Archive -> [Relationship]
archiveToRelationships archive =
  concatMap (filePathToRelationships archive) $ filesInArchive archive

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

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
  lookup ilvl $ map (\l@(i, _, _, _) -> (i, l)) lvls


numElemToNum :: NameSpaces -> Element -> Maybe Numb
numElemToNum ns element
  | isElem ns "w" "num" element = do
      numId <- findAttrByName ns "w" "numId" element
      absNumId <- findChildByName ns "w" "abstractNumId" element
                  >>= findAttrByName ns "w" "val"
      return $ Numb numId absNumId
numElemToNum _ _ = Nothing

absNumElemToAbsNum :: NameSpaces -> Element -> Maybe AbstractNumb
absNumElemToAbsNum ns element
  | isElem ns "w" "abstractNum" element = do
      absNumId <- findAttrByName ns "w" "abstractNumId" element
      let levelElems = findChildrenByName ns "w" "lvl" element
          levels = mapMaybe (levelElemToLevel ns) levelElems
      return $ AbstractNumb absNumId levels
absNumElemToAbsNum _ _ = Nothing

levelElemToLevel :: NameSpaces -> Element -> Maybe Level
levelElemToLevel ns element
  | isElem ns "w" "lvl" element = do
      ilvl <- findAttrByName ns "w" "ilvl" element
      fmt <- findChildByName ns "w" "numFmt" element
             >>= findAttrByName ns "w" "val"
      txt <- findChildByName ns "w" "lvlText" element
             >>= findAttrByName ns "w" "val"
      let start = findChildByName ns "w" "start" element
                  >>= findAttrByName ns "w" "val"
                  >>= (\s -> listToMaybe (map fst (reads s :: [(Integer, String)])))
      return (ilvl, fmt, txt, start)
levelElemToLevel _ _ = Nothing

archiveToNumbering' :: Archive -> Maybe Numbering
archiveToNumbering' zf =
  case findEntryByPath "word/numbering.xml" zf of
    Nothing -> Just $ Numbering [] [] []
    Just entry -> do
      numberingElem <- (parseXMLDoc . UTF8.toStringLazy . fromEntry) entry
      let namespaces = elemToNameSpaces numberingElem
          numElems = findChildrenByName namespaces "w" "num" numberingElem
          absNumElems = findChildrenByName namespaces "w" "abstractNum" 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 -> findAttrByName ns "w" "id" e >>=
                         (\a -> Just (a, e)))
                  (findChildrenByName ns "w" notetype element)
      in
       Just $
       M.fromList pairs
elemToNotes _ _ _ = Nothing

elemToComments :: NameSpaces -> Element -> M.Map String Element
elemToComments ns element
  | isElem ns "w" "comments" element =
      let pairs = mapMaybe
                  (\e -> findAttrByName ns "w" "id" e >>=
                         (\a -> Just (a, e)))
                  (findChildrenByName ns "w" "comment" element)
      in
       M.fromList pairs
elemToComments _ _ = M.empty


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

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

elemToTblLook :: NameSpaces -> Element -> D TblLook
elemToTblLook ns element | isElem ns "w" "tblLook" element =
  let firstRow = findAttrByName ns "w" "firstRow" element
      val = findAttrByName 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 = findChildrenByName 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 =
       findAttrByName ns "w" "left" element >>=
       stringToInteger
    , rightParIndent =
      findAttrByName ns "w" "right" element >>=
      stringToInteger
    , hangingParIndent =
      findAttrByName ns "w" "hanging" element >>=
      stringToInteger}
elemToParIndentation _ _ = 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:_) <- findChildrenByName ns "m" "oMathPara" element =
      do
        expsLst <- eitherToD $ readOMML $ showElement c
        return $ OMathPara expsLst
elemToBodyPart ns element
  | isElem ns "w" "p" element
  , Just (numId, lvl) <- getNumInfo ns element = do
    sty <- asks envParStyles
    let parstyle = elemToParagraphStyle ns element sty
    parparts <- mapD (elemToParPart ns) (elChildren element)
    num <- asks envNumbering
    let levelInfo = lookupLevel numId lvl num
    return $ ListItem parstyle numId lvl levelInfo parparts
elemToBodyPart ns element
  | isElem ns "w" "p" element = do
      sty <- asks envParStyles
      let parstyle = elemToParagraphStyle ns element sty
      parparts <- mapD (elemToParPart ns) (elChildren element)
      -- Word uses list enumeration for numbered headings, so we only
      -- want to infer a list from the styles if it is NOT a heading.
      case pHeading parstyle of
        Nothing | Just (numId, lvl) <- pNumInfo parstyle -> do
                    num <- asks envNumbering
                    let levelInfo = lookupLevel numId lvl num
                    return $ ListItem parstyle numId lvl levelInfo parparts
        _ -> return $ Paragraph parstyle parparts
elemToBodyPart ns element
  | isElem ns "w" "tbl" element = do
    let caption' = findChildByName ns "w" "tblPr" element
                   >>= findChildByName ns "w" "tblCaption"
                   >>= findAttrByName ns "w" "val"
        caption = (fromMaybe "" caption')
        grid' = case findChildByName ns "w" "tblGrid" element of
          Just g  -> elemToTblGrid ns g
          Nothing -> return []
        tblLook' = case findChildByName ns "w" "tblPr" element >>=
                          findChildByName 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 :: DocumentLocation -> RelId -> [Relationship] -> Maybe Target
lookupRelationship docLocation relid rels =
  lookup (docLocation, relid) pairs
  where
    pairs = map (\(Relationship loc relid' target) -> ((loc, relid'), target)) rels

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

getTitleAndAlt :: NameSpaces -> Element -> (String, String)
getTitleAndAlt ns element =
  let mbDocPr = findChildByName ns "wp" "inline" element >>=
                findChildByName ns "wp" "docPr"
      title = fromMaybe "" (mbDocPr >>= findAttrByName ns "" "title")
      alt = fromMaybe "" (mbDocPr >>= findAttrByName ns "" "descr")
  in (title, alt)

elemToParPart :: NameSpaces -> Element -> D ParPart
elemToParPart ns element
  | isElem ns "w" "r" element
  , Just drawingElem <- findChildByName ns "w" "drawing" element
  , pic_ns <- "http://schemas.openxmlformats.org/drawingml/2006/picture"
  , Just picElem <- findElement (QName "pic" (Just pic_ns) (Just "pic")) drawingElem
  = let (title, alt) = getTitleAndAlt ns drawingElem
        a_ns = "http://schemas.openxmlformats.org/drawingml/2006/main"
        drawing = findElement (QName "blip" (Just a_ns) (Just "a")) picElem
                  >>= findAttrByName ns "r" "embed"
    in
     case drawing of
       Just s -> expandDrawingId s >>= (\(fp, bs) -> return $ Drawing fp title alt bs $ elemToExtent drawingElem)
       Nothing -> throwError WrongElem
-- The below is an attempt to deal with images in deprecated vml format.
elemToParPart ns element
  | isElem ns "w" "r" element
  , Just _ <- findChildByName ns "w" "pict" element =
    let drawing = findElement (elemName ns "v" "imagedata") element
                  >>= findAttrByName ns "r" "id"
    in
     case drawing of
       -- Todo: check out title and attr for deprecated format.
       Just s -> expandDrawingId s >>= (\(fp, bs) -> return $ Drawing fp "" "" bs Nothing)
       Nothing -> throwError WrongElem
-- Chart
elemToParPart ns element
  | isElem ns "w" "r" element
  , Just drawingElem <- findChildByName ns "w" "drawing" element
  , c_ns <- "http://schemas.openxmlformats.org/drawingml/2006/chart"
  , Just _ <- findElement (QName "chart" (Just c_ns) (Just "c")) drawingElem
  = return Chart
elemToParPart ns element
  | isElem ns "w" "r" element =
    elemToRun ns element >>= (\r -> return $ PlainRun r)
elemToParPart ns element
  | isElem ns "w" "ins" element || isElem ns "w" "moveTo" element
  , Just cId <- findAttrByName ns "w" "id" element
  , Just cAuthor <- findAttrByName ns "w" "author" element
  , Just cDate <- findAttrByName 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 || isElem ns "w" "moveFrom" element
  , Just cId <- findAttrByName ns "w" "id" element
  , Just cAuthor <- findAttrByName ns "w" "author" element
  , Just cDate <- findAttrByName ns "w" "date" element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    return $ Deletion cId cAuthor cDate runs
elemToParPart ns element
  | isElem ns "w" "smartTag" element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    return $ SmartTag runs
elemToParPart ns element
  | isElem ns "w" "bookmarkStart" element
  , Just bmId <- findAttrByName ns "w" "id" element
  , Just bmName <- findAttrByName ns "w" "name" element =
    return $ BookMark bmId bmName
elemToParPart ns element
  | isElem ns "w" "hyperlink" element
  , Just relId <- findAttrByName ns "r" "id" element = do
    location <- asks envLocation
    runs <- mapD (elemToRun ns) (elChildren element)
    rels <- asks envRelationships
    case lookupRelationship location relId rels of
      Just target ->
         case findAttrByName ns "w" "anchor" element of
             Just anchor -> return $ ExternalHyperLink (target ++ '#':anchor) runs
             Nothing -> return $ ExternalHyperLink target runs
      Nothing     -> return $ ExternalHyperLink "" runs
elemToParPart ns element
  | isElem ns "w" "hyperlink" element
  , Just anchor <- findAttrByName ns "w" "anchor" element = do
    runs <- mapD (elemToRun ns) (elChildren element)
    return $ InternalHyperLink anchor runs
elemToParPart ns element
  | isElem ns "w" "commentRangeStart" element
  , Just cmtId <- findAttrByName ns "w" "id" element = do
      (Comments _ commentMap) <- asks envComments
      case M.lookup cmtId commentMap of
        Just cmtElem -> elemToCommentStart ns cmtElem
        Nothing      -> throwError WrongElem
elemToParPart ns element
  | isElem ns "w" "commentRangeEnd" element
  , Just cmtId <- findAttrByName ns "w" "id" element =
    return $ CommentEnd cmtId
elemToParPart ns element
  | isElem ns "m" "oMath" element =
    fmap PlainOMath (eitherToD $ readOMML $ showElement element)
elemToParPart _ _ = throwError WrongElem

elemToCommentStart :: NameSpaces -> Element -> D ParPart
elemToCommentStart ns element
  | isElem ns "w" "comment" element
  , Just cmtId <- findAttrByName ns "w" "id" element
  , Just cmtAuthor <- findAttrByName ns "w" "author" element
  , Just cmtDate <- findAttrByName ns "w" "date" element = do
      bps <- mapD (elemToBodyPart ns) (elChildren element)
      return $ CommentStart cmtId cmtAuthor cmtDate bps
elemToCommentStart _ _ = 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

elemToExtent :: Element -> Extent
elemToExtent drawingElem =
  case (getDim "cx", getDim "cy") of
    (Just w, Just h) -> Just (w, h)
    _                -> Nothing
    where
      wp_ns  = "http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing"
      getDim at = findElement (QName "extent" (Just wp_ns) (Just "wp")) drawingElem
                    >>= findAttr (QName at Nothing Nothing) >>= safeRead


childElemToRun :: NameSpaces -> Element -> D Run
childElemToRun ns element
  | isElem ns "w" "drawing" element
  , pic_ns <- "http://schemas.openxmlformats.org/drawingml/2006/picture"
  , Just picElem <- findElement (QName "pic" (Just pic_ns) (Just "pic")) element
  = let (title, alt) = getTitleAndAlt ns element
        a_ns = "http://schemas.openxmlformats.org/drawingml/2006/main"
        drawing = findElement (QName "blip" (Just a_ns) (Just "a")) picElem
                  >>= findAttr (QName "embed" (lookup "r" ns) (Just "r"))
    in
     case drawing of
       Just s -> expandDrawingId s >>=
                 (\(fp, bs) -> return $ InlineDrawing fp title alt bs $ elemToExtent element)
       Nothing -> throwError WrongElem
childElemToRun ns element
  | isElem ns "w" "drawing" element
  , c_ns <- "http://schemas.openxmlformats.org/drawingml/2006/chart"
  , Just _ <- findElement (QName "chart" (Just c_ns) (Just "c")) element
  = return InlineChart
childElemToRun ns element
  | isElem ns "w" "footnoteReference" element
  , Just fnId <- findAttrByName ns "w" "id" element = do
    notes <- asks envNotes
    case lookupFootnote fnId notes of
      Just e -> do bps <- local (\r -> r {envLocation=InFootnote}) $ mapD (elemToBodyPart ns) (elChildren e)
                   return $ Footnote bps
      Nothing  -> return $ Footnote []
childElemToRun ns element
  | isElem ns "w" "endnoteReference" element
  , Just enId <- findAttrByName ns "w" "id" element = do
    notes <- asks envNotes
    case lookupEndnote enId notes of
      Just e -> do bps <- local (\r -> r {envLocation=InEndnote}) $ mapD (elemToBodyPart ns) (elChildren e)
                   return $ Endnote bps
      Nothing  -> return $ Endnote []
childElemToRun _ _ = throwError WrongElem

elemToRun :: NameSpaces -> Element -> D Run
elemToRun ns element
  | isElem ns "w" "r" element
  , Just altCont <- findChildByName ns "mc" "AlternateContent" element =
    do let choices = findChildrenByName ns "mc" "Choice" altCont
           choiceChildren = map head $ filter (not . null) $ map elChildren choices
       outputs <- mapD (childElemToRun ns) choiceChildren
       case outputs of
         r : _ -> return r
         []    -> throwError WrongElem
elemToRun ns element
  | isElem ns "w" "r" element
  , Just drawingElem <- findChildByName ns "w" "drawing" element =
    childElemToRun ns drawingElem
elemToRun ns element
  | isElem ns "w" "r" element
  , Just ref <- findChildByName ns "w" "footnoteReference" element =
    childElemToRun ns ref
elemToRun ns element
  | isElem ns "w" "r" element
  , Just ref <- findChildByName ns "w" "endnoteReference" element =
    childElemToRun ns ref
elemToRun ns element
  | isElem ns "w" "r" element = do
    runElems <- elemToRunElems ns element
    runStyle <- elemToRunStyleD ns element
    return $ Run runStyle runElems
elemToRun _ _ = throwError WrongElem

getParentStyleValue :: (ParStyleData -> Maybe a) -> ParStyleData -> Maybe a
getParentStyleValue field style
  | Just value <- field style = Just value
  | Just parentStyle <- psStyle style
                      = getParentStyleValue field (snd parentStyle)
getParentStyleValue _ _ = Nothing

getParStyleField :: (ParStyleData -> Maybe a) -> ParStyleMap -> [String] ->
                                                                        Maybe a
getParStyleField field stylemap styles
  | x     <- mapMaybe (\x -> M.lookup x stylemap) styles
  , (y:_) <- mapMaybe (getParentStyleValue field) x
           = Just y
getParStyleField _ _ _ = Nothing

elemToParagraphStyle :: NameSpaces -> Element -> ParStyleMap -> ParagraphStyle
elemToParagraphStyle ns element sty
  | Just pPr <- findChildByName ns "w" "pPr" element =
    let style =
          mapMaybe
          (findAttrByName ns "w" "val")
          (findChildrenByName ns "w" "pStyle" pPr)
    in ParagraphStyle
      {pStyle = style
      , indentation =
          findChildByName ns "w" "ind" pPr >>=
          elemToParIndentation ns
      , dropCap =
          case
            findChildByName ns "w" "framePr" pPr >>=
            findAttrByName ns "w" "dropCap"
          of
            Just "none" -> False
            Just _      -> True
            Nothing     -> False
      , pHeading = getParStyleField headingLev sty style
      , pNumInfo = getParStyleField numInfo sty style
      , pBlockQuote = getParStyleField isBlockQuote sty style
      }
elemToParagraphStyle _ _ _ =  defaultParagraphStyle

checkOnOff :: NameSpaces -> Element -> QName -> Maybe Bool
checkOnOff ns rPr tag
  | Just t <-  findChild tag rPr
  , Just val <- findAttrByName ns "w" "val" t =
    Just $ case val of
      "true"  -> True
      "false" -> False
      "on"    -> True
      "off"   -> False
      "1"     -> True
      "0"     -> False
      _       -> False
  | Just _ <- findChild tag rPr = Just True
checkOnOff _ _ _ = Nothing

elemToRunStyleD :: NameSpaces -> Element -> D RunStyle
elemToRunStyleD ns element
  | Just rPr <- findChildByName ns "w" "rPr" element = do
    charStyles <- asks envCharStyles
    let parentSty = case
          findChildByName ns "w" "rStyle" rPr >>=
          findAttrByName ns "w" "val"
          of
            Just styName | Just style <- M.lookup styName charStyles ->
              Just (styName, style)
            _            -> Nothing
    return $ elemToRunStyle ns element parentSty
elemToRunStyleD _ _ = return defaultRunStyle

elemToRunStyle :: NameSpaces -> Element -> Maybe CharStyle -> RunStyle
elemToRunStyle ns element parentStyle
  | Just rPr <- findChildByName ns "w" "rPr" element =
    RunStyle
      {
        isBold = checkOnOff ns rPr (elemName ns "w" "b")
      , isItalic = checkOnOff ns rPr (elemName ns "w" "i")
      , isSmallCaps = checkOnOff ns rPr (elemName ns "w" "smallCaps")
      , isStrike = checkOnOff ns rPr (elemName ns "w" "strike")
      , rVertAlign =
           findChildByName ns "w" "vertAlign" rPr >>=
           findAttrByName ns "w" "val" >>=
           \v -> Just $ case v of
             "superscript" -> SupScrpt
             "subscript"   -> SubScrpt
             _             -> BaseLn
      , rUnderline =
          findChildByName ns "w" "u" rPr >>=
          findAttrByName ns "w" "val"
      , rStyle = parentStyle
        }
elemToRunStyle _ _ _ = defaultRunStyle

getHeaderLevel :: NameSpaces -> Element -> Maybe (String,Int)
getHeaderLevel ns element
  | Just styleId <- findAttrByName ns "w" "styleId" element
  , Just index   <- stripPrefix "Heading" styleId
  , Just n       <- stringToInteger index
  , n > 0 = Just (styleId, fromInteger n)
  | Just styleId <- findAttrByName ns "w" "styleId" element
  , Just index   <- findChildByName ns "w" "name" element >>=
                    findAttrByName ns "w" "val" >>=
                    stripPrefix "heading "
  , Just n <- stringToInteger index
  , n > 0 = Just (styleId, fromInteger n)
getHeaderLevel _ _ = Nothing

blockQuoteStyleIds :: [String]
blockQuoteStyleIds = ["Quote", "BlockQuote", "BlockQuotation"]

blockQuoteStyleNames :: [String]
blockQuoteStyleNames = ["Quote", "Block Text"]

getBlockQuote :: NameSpaces -> Element -> Maybe Bool
getBlockQuote ns element
  | Just styleId <- findAttrByName ns "w" "styleId" element
  , styleId `elem` blockQuoteStyleIds = Just True
  | Just styleName <- findChildByName ns "w" "name" element >>=
                      findAttrByName ns "w" "val"
  , styleName `elem` blockQuoteStyleNames = Just True
getBlockQuote _ _ = Nothing

getNumInfo :: NameSpaces -> Element -> Maybe (String, String)
getNumInfo ns element = do
  let numPr = findChildByName ns "w" "pPr" element >>=
              findChildByName ns "w" "numPr"
      lvl = fromMaybe "0" (numPr >>=
                           findChildByName ns "w" "ilvl" >>=
                           findAttrByName ns "w" "val")
  numId <- numPr >>=
           findChildByName ns "w" "numId" >>=
           findAttrByName ns "w" "val"
  return (numId, lvl)


elemToParStyleData :: NameSpaces -> Element -> Maybe ParStyle -> ParStyleData
elemToParStyleData ns element parentStyle =
    ParStyleData
      {
        headingLev = getHeaderLevel ns element
      , isBlockQuote = getBlockQuote ns element
      , numInfo = getNumInfo ns element
      , psStyle = parentStyle
        }

elemToRunElem :: NameSpaces -> Element -> D RunElem
elemToRunElem ns element
  | isElem ns "w" "t" element
    || isElem ns "w" "delText" element
    || isElem ns "m" "t" element = do
    let str = strContent element
    font <- asks envFont
    case font of
      Nothing -> return $ TextRun str
      Just f  -> return . TextRun $
                  map (\x -> fromMaybe x . getUnicode f . lowerFromPrivate $ x) str
  | isElem ns "w" "br" element = return LnBrk
  | isElem ns "w" "tab" element = return Tab
  | isElem ns "w" "softHyphen" element = return SoftHyphen
  | isElem ns "w" "noBreakHyphen" element = return NoBreakHyphen
  | isElem ns "w" "sym" element = return (getSymChar ns element)
  | otherwise = throwError WrongElem
  where
    lowerFromPrivate (ord -> c)
      | c >= ord '\xF000' = chr $ c - ord '\xF000'
      | otherwise = chr c

-- 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 = findAttrByName ns "w" "char" element
    getFont = stringToFont =<< findAttrByName ns "w" "font" element
    lowerFromPrivate ('F':xs) = '0':xs
    lowerFromPrivate xs       = xs
getSymChar _ _ = TextRun ""

elemToRunElems :: NameSpaces -> Element -> D [RunElem]
elemToRunElems ns element
  |  isElem ns "w" "r" element
     || isElem ns "m" "r" element = do
       let qualName = elemName ns "w"
       let font = do
                    fontElem <- findElement (qualName "rFonts") element
                    stringToFont =<<
                      foldr (<|>) Nothing (
                        map (flip findAttr fontElem . qualName) ["ascii", "hAnsi"])
       local (setFont font) (mapD (elemToRunElem ns) (elChildren element))
elemToRunElems _ _ = throwError WrongElem

setFont :: Maybe Font -> ReaderEnv -> ReaderEnv
setFont f s = s{envFont = f}