aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Writers/EPUB.hs
blob: 4daa9609e741355480097ef68b4ecd735e2b8f68 (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
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
{-# LANGUAGE PatternGuards, CPP, ScopedTypeVariables #-}
{-
Copyright (C) 2010 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.EPUB
   Copyright   : Copyright (C) 2010 John MacFarlane
   License     : GNU GPL, version 2 or above

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

Conversion of 'Pandoc' documents to EPUB.
-}
module Text.Pandoc.Writers.EPUB ( writeEPUB ) where
import Data.IORef
import qualified Data.Map as M
import Data.Maybe ( fromMaybe )
import Data.List ( isInfixOf, intercalate )
import System.Environment ( getEnv )
import Text.Printf (printf)
import System.FilePath ( (</>), takeBaseName, takeExtension, takeFileName )
import qualified Data.ByteString.Lazy as B
import qualified Data.ByteString.Lazy.Char8 as B8
import qualified Text.Pandoc.UTF8 as UTF8
import Text.Pandoc.SelfContained ( makeSelfContained )
import Codec.Archive.Zip
import Control.Applicative ((<$>))
import Data.Time.Clock.POSIX
import Data.Time
import System.Locale
import Text.Pandoc.Shared hiding ( Element )
import qualified Text.Pandoc.Shared as Shared
import Text.Pandoc.Builder (fromList, setMeta)
import Text.Pandoc.Options
import Text.Pandoc.Definition
import Text.Pandoc.Walk
import Control.Monad.State
import Text.XML.Light hiding (ppTopElement)
import Text.Pandoc.UUID
import Text.Pandoc.Writers.HTML
import Text.Pandoc.Writers.Markdown ( writePlain )
import Data.Char ( toLower, isDigit )
import Network.URI ( unEscapeString )
import Text.Pandoc.MIME (getMimeType)
#if MIN_VERSION_base(4,6,0)
#else
import Prelude hiding (catch)
#endif
import Control.Exception (catch, SomeException)
import Text.Blaze.Html.Renderer.Utf8 (renderHtml)

-- A Chapter includes a list of blocks and maybe a section
-- number offset.  Note, some chapters are unnumbered. The section
-- number is different from the index number, which will be used
-- in filenames, chapter0003.xhtml.
data Chapter = Chapter (Maybe [Int]) [Block]

data EPUBMetadata = EPUBMetadata{
    epubIdentifier         :: [Identifier]
  , epubTitle              :: [Title]
  , epubDate               :: String
  , epubLanguage           :: String
  , epubCreator            :: [Creator]
  , epubContributor        :: [Creator]
  , epubSubject            :: [String]
  , epubDescription        :: Maybe String
  , epubType               :: Maybe String
  , epubFormat             :: Maybe String
  , epubPublisher          :: Maybe String
  , epubSource             :: Maybe String
  , epubRelation           :: Maybe String
  , epubCoverage           :: Maybe String
  , epubRights             :: Maybe String
  , epubCoverImage         :: Maybe String
  , epubStylesheet         :: Maybe Stylesheet
  } deriving Show

data Stylesheet = StylesheetPath FilePath
                | StylesheetContents String
                deriving Show

data Creator = Creator{
    creatorText            :: String
  , creatorRole            :: Maybe String
  , creatorFileAs          :: Maybe String
  } deriving Show

data Identifier = Identifier{
    identifierText         :: String
  , identifierScheme       :: Maybe String
  } deriving Show

data Title = Title{
    titleText              :: String
  , titleFileAs            :: Maybe String
  , titleType              :: Maybe String
  } deriving Show

dcName :: String -> QName
dcName n = QName n Nothing (Just "dc")

dcNode :: Node t => String -> t -> Element
dcNode = node . dcName

opfName :: String -> QName
opfName n = QName n Nothing (Just "opf")

plainify :: [Inline] -> String
plainify t =
  trimr $ writePlain def{ writerStandalone = False } $ Pandoc nullMeta [Plain t]

getEPUBMetadata :: WriterOptions -> Meta -> IO EPUBMetadata
getEPUBMetadata opts meta = do
  let md = metadataFromMeta opts meta
  let elts = onlyElems $ parseXML $ writerEpubMetadata opts
  let md' = foldr addMetadataFromXML md elts
  let addIdentifier m =
       if null (epubIdentifier m)
          then do
            randomId <- fmap show getRandomUUID
            return $ m{ epubIdentifier = [Identifier randomId Nothing] }
          else return m
  let addLanguage m =
       if null (epubLanguage m)
          then case lookup "lang" (writerVariables opts) of
                     Just x  -> return m{ epubLanguage = x }
                     Nothing -> do
                       localeLang <- catch (liftM
                            (map (\c -> if c == '_' then '-' else c) .
                             takeWhile (/='.')) $ getEnv "LANG")
                          (\e -> let _ = (e :: SomeException) in return "en-US")
                       return m{ epubLanguage = localeLang }
          else return m
  let fixDate m =
       if null (epubDate m)
          then do
            currentTime <- getCurrentTime
            return $ m{ epubDate = showDateTimeISO8601 currentTime }
          else return m
  let addAuthor m =
       if any (\c -> creatorRole c == Just "aut") $ epubCreator m
          then return m
          else do
            let authors' = map plainify $ docAuthors meta
            let toAuthor name = Creator{ creatorText = name
                                       , creatorRole = Just "aut"
                                       , creatorFileAs = Nothing }
            return $ m{ epubCreator = map toAuthor authors' ++ epubCreator m }
  addIdentifier md' >>= fixDate >>= addAuthor >>= addLanguage

addMetadataFromXML :: Element -> EPUBMetadata -> EPUBMetadata
addMetadataFromXML e@(Element (QName name _ (Just "dc")) attrs _ _) md
  | name == "identifier" = md{ epubIdentifier =
             Identifier{ identifierText = strContent e
                       , identifierScheme = lookupAttr (opfName "scheme") attrs
                       } : epubIdentifier md }
  | name == "title" = md{ epubTitle =
            Title{ titleText = strContent e
                 , titleFileAs = getAttr "file-as"
                 , titleType = getAttr "type"
                 } : epubTitle md }
  | name == "date" = md{ epubDate = fromMaybe "" $ normalizeDate'
                                                 $ strContent e }
  | name == "language" = md{ epubLanguage = strContent e }
  | name == "creator" = md{ epubCreator =
              Creator{ creatorText = strContent e
                     , creatorRole = getAttr "role"
                     , creatorFileAs = getAttr "file-as"
                     } : epubCreator md }
  | name == "contributor" = md{ epubContributor =
              Creator  { creatorText = strContent e
                       , creatorRole = getAttr "role"
                       , creatorFileAs = getAttr "file-as"
                       } : epubContributor md }
  | name == "subject" = md{ epubSubject = strContent e : epubSubject md }
  | name == "description" = md { epubDescription = Just $ strContent e }
  | name == "type" = md { epubType = Just $ strContent e }
  | name == "format" = md { epubFormat = Just $ strContent e }
  | name == "type" = md { epubType = Just $ strContent e }
  | name == "publisher" = md { epubPublisher = Just $ strContent e }
  | name == "source" = md { epubSource = Just $ strContent e }
  | name == "relation" = md { epubRelation = Just $ strContent e }
  | name == "coverage" = md { epubCoverage = Just $ strContent e }
  | name == "rights" = md { epubRights = Just $ strContent e }
  | otherwise = md
  where getAttr n = lookupAttr (opfName n) attrs
addMetadataFromXML _ md = md

metaValueToString :: MetaValue -> String
metaValueToString (MetaString s) = s
metaValueToString (MetaInlines ils) = plainify ils
metaValueToString (MetaBlocks bs) = plainify $ query (:[]) bs
metaValueToString (MetaBool b) = show b
metaValueToString _ = ""

getList :: String -> Meta -> (MetaValue -> a) -> [a]
getList s meta handleMetaValue =
  case lookupMeta s meta of
       Just (MetaList xs) -> map handleMetaValue xs
       Just mv            -> [handleMetaValue mv]
       Nothing            -> []

getIdentifier :: Meta -> [Identifier]
getIdentifier meta = getList "identifier" meta handleMetaValue
  where handleMetaValue (MetaMap m) =
           Identifier{ identifierText = maybe "" metaValueToString
                                        $ M.lookup "text" m
                     , identifierScheme = metaValueToString <$>
                                          M.lookup "scheme" m }
        handleMetaValue mv = Identifier (metaValueToString mv) Nothing

getTitle :: Meta -> [Title]
getTitle meta = getList "title" meta handleMetaValue
  where handleMetaValue (MetaMap m) =
           Title{ titleText = maybe "" metaValueToString $ M.lookup "text" m
                , titleFileAs = metaValueToString <$> M.lookup "file-as" m
                , titleType = metaValueToString <$> M.lookup "type" m }
        handleMetaValue mv = Title (metaValueToString mv) Nothing Nothing

getCreator :: String -> Meta -> [Creator]
getCreator s meta = getList s meta handleMetaValue
  where handleMetaValue (MetaMap m) =
           Creator{ creatorText = maybe "" metaValueToString $ M.lookup "text" m
                  , creatorFileAs = metaValueToString <$> M.lookup "file-as" m
                  , creatorRole = metaValueToString <$> M.lookup "role" m }
        handleMetaValue mv = Creator (metaValueToString mv) Nothing Nothing

simpleList :: String -> Meta -> [String]
simpleList s meta =
  case lookupMeta s meta of
       Just (MetaList xs) -> map metaValueToString xs
       Just x -> [metaValueToString x]
       Nothing -> []

metadataFromMeta :: WriterOptions -> Meta -> EPUBMetadata
metadataFromMeta opts meta = EPUBMetadata{
      epubIdentifier         = identifiers
    , epubTitle              = titles
    , epubDate               = date
    , epubLanguage           = language
    , epubCreator            = creators
    , epubContributor        = contributors
    , epubSubject            = subjects
    , epubDescription        = description
    , epubType               = epubtype
    , epubFormat             = format
    , epubPublisher          = publisher
    , epubSource             = source
    , epubRelation           = relation
    , epubCoverage           = coverage
    , epubRights             = rights
    , epubCoverImage         = coverImage
    , epubStylesheet         = stylesheet
    }
  where identifiers = getIdentifier meta
        titles = getTitle meta
        date = fromMaybe "" $
              (metaValueToString <$> lookupMeta "date" meta) >>= normalizeDate'
        language = maybe "" metaValueToString $
           lookupMeta "language" meta `mplus` lookupMeta "lang" meta
        creators = getCreator "creator" meta
        contributors = getCreator "contributor" meta
        subjects = simpleList "subject" meta
        description = metaValueToString <$> lookupMeta "description" meta
        epubtype = metaValueToString <$> lookupMeta "type" meta
        format = metaValueToString <$> lookupMeta "format" meta
        publisher = metaValueToString <$> lookupMeta "publisher" meta
        source = metaValueToString <$> lookupMeta "source" meta
        relation = metaValueToString <$> lookupMeta "relation" meta
        coverage = metaValueToString <$> lookupMeta "coverage" meta
        rights = metaValueToString <$> lookupMeta "rights" meta
        coverImage = lookup "epub-cover-image" (writerVariables opts) `mplus`
             (metaValueToString <$> lookupMeta "cover-image" meta)
        stylesheet = (StylesheetContents <$> writerEpubStylesheet opts) `mplus`
                     ((StylesheetPath . metaValueToString) <$>
                       lookupMeta "stylesheet" meta)

-- | Produce an EPUB file from a Pandoc document.
writeEPUB :: WriterOptions  -- ^ Writer options
          -> Pandoc         -- ^ Document to convert
          -> IO B.ByteString
writeEPUB opts doc@(Pandoc meta _) = do
  let version = fromMaybe EPUB2 (writerEpubVersion opts)
  let epub3 = version == EPUB3
  epochtime <- floor `fmap` getPOSIXTime
  let mkEntry path content = toEntry path epochtime content
  let vars = ("epub3", if epub3 then "true" else "false")
           : ("css", "stylesheet.css")
           : writerVariables opts
  let opts' = opts{ writerEmailObfuscation = NoObfuscation
                  , writerStandalone = True
                  , writerSectionDivs = True
                  , writerHtml5 = epub3
                  , writerTableOfContents = False -- we always have one in epub
                  , writerVariables = vars
                  , writerHTMLMathMethod =
                       if epub3
                          then MathML Nothing
                          else writerHTMLMathMethod opts
                  , writerWrapText = False }
  metadata <- getEPUBMetadata opts' meta

  -- cover page
  (cpgEntry, cpicEntry) <-
                case epubCoverImage metadata of
                     Nothing   -> return ([],[])
                     Just img  -> do
                       let coverImage = "cover-image" ++ takeExtension img
                       let cpContent = renderHtml $ writeHtml opts'
                               (Pandoc meta [RawBlock (Format "html") $ "<div id=\"cover-image\">\n<img src=\"" ++ coverImage ++ "\" alt=\"cover image\" />\n</div>"])
                       imgContent <- B.readFile img
                       return ( [mkEntry "cover.xhtml" cpContent]
                              , [mkEntry coverImage imgContent] )

  -- title page
  let tpContent = renderHtml $ writeHtml opts'{
                      writerVariables = ("titlepage","true"):vars }
                      (Pandoc meta [])
  let tpEntry = mkEntry "title_page.xhtml" tpContent

  -- handle pictures
  picsRef <- newIORef []
  Pandoc _ blocks <- walkM
       (transformInline opts' picsRef) doc
  pics <- readIORef picsRef
  let readPicEntry entries (oldsrc, newsrc) = do
        res <- fetchItem (writerSourceURL opts') oldsrc
        case res of
             Left _        -> do
              warn $ "Could not find image `" ++ oldsrc ++ "', skipping..."
              return entries
             Right (img,_) -> return $
              (toEntry newsrc epochtime $ B.fromChunks . (:[]) $ img) : entries
  picEntries <- foldM readPicEntry [] pics

  -- handle fonts
  let mkFontEntry f = mkEntry (takeFileName f) `fmap` B.readFile f
  fontEntries <- mapM mkFontEntry $ writerEpubFonts opts'

  -- body pages

  -- add level 1 header to beginning if none there
  let blocks' = addIdentifiers
                $ case blocks of
                      (Header 1 _ _ : _) -> blocks
                      _                  -> Header 1 ("",["unnumbered"],[])
                                                 (docTitle meta) : blocks

  let chapterHeaderLevel = writerEpubChapterLevel opts
  -- internal reference IDs change when we chunk the file,
  -- so that '#my-header-1' might turn into 'chap004.xhtml#my-header'.
  -- the next two lines fix that:
  let reftable = correlateRefs chapterHeaderLevel blocks'
  let blocks'' = replaceRefs reftable blocks'

  let isChapterHeader (Header n _ _) = n <= chapterHeaderLevel
      isChapterHeader _ = False

  let toChapters :: [Block] -> State [Int] [Chapter]
      toChapters []     = return []
      toChapters (Header n attr@(_,classes,_) ils : bs) = do
        nums <- get
        mbnum <- if "unnumbered" `elem` classes
                    then return Nothing
                    else case splitAt (n - 1) nums of
                              (ks, (m:_)) -> do
                                let nums' = ks ++ [m+1]
                                put nums'
                                return $ Just (ks ++ [m])
                                -- note, this is the offset not the sec number
                              (ks, []) -> do
                                let nums' = ks ++ [1]
                                put nums'
                                return $ Just ks
        let (xs,ys) = break isChapterHeader bs
        (Chapter mbnum (Header n attr ils : xs) :) `fmap` toChapters ys
      toChapters (b:bs) = do
        let (xs,ys) = break isChapterHeader bs
        (Chapter Nothing (b:xs) :) `fmap` toChapters ys

  let chapters = evalState (toChapters blocks'') []

  let chapToEntry :: Int -> Chapter -> Entry
      chapToEntry num (Chapter mbnum bs) = mkEntry (showChapter num)
        $ renderHtml
        $ writeHtml opts'{ writerNumberOffset =
            fromMaybe [] mbnum }
        $ case bs of
              (Header _ _ xs : _) ->
                 Pandoc (setMeta "title" (fromList xs) nullMeta) bs
              _                   ->
                 Pandoc nullMeta bs

  let chapterEntries = zipWith chapToEntry [1..] chapters

  -- incredibly inefficient (TODO):
  let containsMathML ent = epub3 &&
                           "<math" `isInfixOf` (B8.unpack $ fromEntry ent)
  let containsSVG ent    = epub3 &&
                           "<svg" `isInfixOf` (B8.unpack $ fromEntry ent)
  let props ent = ["mathml" | containsMathML ent] ++ ["svg" | containsSVG ent]

  -- contents.opf
  let chapterNode ent = unode "item" !
                           ([("id", takeBaseName $ eRelativePath ent),
                             ("href", eRelativePath ent),
                             ("media-type", "application/xhtml+xml")]
                            ++ case props ent of
                                    []   -> []
                                    xs   -> [("properties", unwords xs)])
                        $ ()
  let chapterRefNode ent = unode "itemref" !
                             [("idref", takeBaseName $ eRelativePath ent)] $ ()
  let pictureNode ent = unode "item" !
                           [("id", takeBaseName $ eRelativePath ent),
                            ("href", eRelativePath ent),
                            ("media-type", fromMaybe "application/octet-stream"
                               $ imageTypeOf $ eRelativePath ent)] $ ()
  let fontNode ent = unode "item" !
                           [("id", takeBaseName $ eRelativePath ent),
                            ("href", eRelativePath ent),
                            ("media-type", fromMaybe "" $ getMimeType $ eRelativePath ent)] $ ()
  let plainTitle = case docTitle meta of
                        [] -> case epubTitle metadata of
                                   []   -> "UNTITLED"
                                   (x:_) -> titleText x
                        x  -> plainify x
  let uuid = case epubIdentifier metadata of
                  (x:_) -> identifierText x  -- use first identifier as UUID
                  []    -> error "epubIdentifier is null"  -- shouldn't happen
  currentTime <- getCurrentTime
  let contentsData = UTF8.fromStringLazy $ ppTopElement $
        unode "package" ! [("version", case version of
                                             EPUB2 -> "2.0"
                                             EPUB3 -> "3.0")
                          ,("xmlns","http://www.idpf.org/2007/opf")
                          ,("unique-identifier","epub-id-1")] $
          [ metadataElement version metadata currentTime
          , unode "manifest" $
             [ unode "item" ! [("id","ncx"), ("href","toc.ncx")
                              ,("media-type","application/x-dtbncx+xml")] $ ()
             , unode "item" ! [("id","style"), ("href","stylesheet.css")
                              ,("media-type","text/css")] $ ()
             , unode "item" ! ([("id","nav")
                               ,("href","nav.xhtml")
                               ,("media-type","application/xhtml+xml")] ++
                               [("properties","nav") | epub3 ]) $ ()
             ] ++
             map chapterNode (cpgEntry ++ (tpEntry : chapterEntries)) ++
             (case cpicEntry of
                    []    -> []
                    (x:_) -> [add_attrs
                              [Attr (unqual "properties") "cover-image" | epub3]
                              (pictureNode x)]) ++
             map pictureNode picEntries ++
             map fontNode fontEntries
          , unode "spine" ! [("toc","ncx")] $
              case epubCoverImage metadata of
                    Nothing -> []
                    Just _ -> [ unode "itemref" !
                                [("idref", "cover"),("linear","no")] $ () ]
              ++ ((unode "itemref" ! [("idref", "title_page")
                                     ,("linear", if null (docTitle meta)
                                                    then "no"
                                                    else "yes")] $ ()) :
                  (unode "itemref" ! [("idref", "nav")
                                     ,("linear", if writerTableOfContents opts
                                                    then "yes"
                                                    else "no")] $ ()) :
                  map chapterRefNode chapterEntries)
          , unode "guide" $
             [ unode "reference" !
                   [("type","toc"),("title",plainTitle),
                    ("href","nav.xhtml")] $ ()
             ] ++
             [ unode "reference" !
                   [("type","cover"),("title","Cover"),("href","cover.xhtml")] $ () | epubCoverImage metadata /= Nothing
             ]
          ]
  let contentsEntry = mkEntry "content.opf" contentsData

  -- toc.ncx
  let secs = hierarchicalize blocks''

  let tocLevel = writerTOCDepth opts

  let navPointNode :: (Int -> String -> String -> [Element] -> Element)
                   -> Shared.Element -> State Int Element
      navPointNode formatter (Sec _ nums (ident,_,_) ils children) = do
        n <- get
        modify (+1)
        let showNums :: [Int] -> String
            showNums = intercalate "." . map show
        let tit' = plainify ils
        let tit = if writerNumberSections opts && not (null nums)
                     then showNums nums ++ " " ++ tit'
                     else tit'
        let src = case lookup ident reftable of
                       Just x  -> x
                       Nothing -> error (ident ++ " not found in reftable")
        let isSec (Sec lev _ _ _ _) = lev <= tocLevel
            isSec _                 = False
        let subsecs = filter isSec children
        subs <- mapM (navPointNode formatter) subsecs
        return $ formatter n tit src subs
      navPointNode _ (Blk _) = error "navPointNode encountered Blk"

  let navMapFormatter :: Int -> String -> String -> [Element] -> Element
      navMapFormatter n tit src subs = unode "navPoint" !
               [("id", "navPoint-" ++ show n)
               ,("playOrder", show n)] $
                  [ unode "navLabel" $ unode "text" tit
                  , unode "content" ! [("src", src)] $ ()
                  ] ++ subs

  let tpNode = unode "navPoint" !  [("id", "navPoint-0")] $
                  [ unode "navLabel" $ unode "text" (plainify $ docTitle meta)
                  , unode "content" ! [("src","title_page.xhtml")] $ () ]

  let tocData = UTF8.fromStringLazy $ ppTopElement $
        unode "ncx" ! [("version","2005-1")
                       ,("xmlns","http://www.daisy.org/z3986/2005/ncx/")] $
          [ unode "head" $
             [ unode "meta" ! [("name","dtb:uid")
                              ,("content", uuid)] $ ()
             , unode "meta" ! [("name","dtb:depth")
                              ,("content", "1")] $ ()
             , unode "meta" ! [("name","dtb:totalPageCount")
                              ,("content", "0")] $ ()
             , unode "meta" ! [("name","dtb:maxPageNumber")
                              ,("content", "0")] $ ()
             ] ++ case epubCoverImage metadata of
                        Nothing  -> []
                        Just _   -> [unode "meta" ! [("name","cover"),
                                            ("content","cover-image")] $ ()]
          , unode "docTitle" $ unode "text" $ plainTitle
          , unode "navMap" $
              tpNode : evalState (mapM (navPointNode navMapFormatter) secs) 1
          ]
  let tocEntry = mkEntry "toc.ncx" tocData

  let navXhtmlFormatter :: Int -> String -> String -> [Element] -> Element
      navXhtmlFormatter n tit src subs = unode "li" !
                                       [("id", "toc-li-" ++ show n)] $
                                            (unode "a" ! [("href",src)]
                                             $ (unode "span" tit))
                                            : case subs of
                                                 []    -> []
                                                 (_:_) -> [unode "ol" ! [("class","toc")] $ subs]

  let navtag = if epub3 then "nav" else "div"
  let navData = UTF8.fromStringLazy $ ppTopElement $
        unode "html" ! [("xmlns","http://www.w3.org/1999/xhtml")
                       ,("xmlns:epub","http://www.idpf.org/2007/ops")] $
          [ unode "head" $
            [ unode "title" plainTitle
            , unode "link" ! [("rel","stylesheet"),("type","text/css"),("href","stylesheet.css")] $ () ]
          , unode "body" $
              unode navtag ! [("epub:type","toc") | epub3] $
                [ unode "h1" ! [("id","toc-title")] $ plainTitle
                , unode "ol" ! [("class","toc")] $ evalState (mapM (navPointNode navXhtmlFormatter) secs) 1]
          ]
  let navEntry = mkEntry "nav.xhtml" navData

  -- mimetype
  let mimetypeEntry = mkEntry "mimetype" $ UTF8.fromStringLazy "application/epub+zip"

  -- container.xml
  let containerData = UTF8.fromStringLazy $ ppTopElement $
       unode "container" ! [("version","1.0")
              ,("xmlns","urn:oasis:names:tc:opendocument:xmlns:container")] $
         unode "rootfiles" $
           unode "rootfile" ! [("full-path","content.opf")
               ,("media-type","application/oebps-package+xml")] $ ()
  let containerEntry = mkEntry "META-INF/container.xml" containerData

  -- com.apple.ibooks.display-options.xml
  let apple = UTF8.fromStringLazy $ ppTopElement $
        unode "display_options" $
          unode "platform" ! [("name","*")] $
            unode "option" ! [("name","specified-fonts")] $ "true"
  let appleEntry = mkEntry "META-INF/com.apple.ibooks.display-options.xml" apple

  -- stylesheet
  stylesheet <- case epubStylesheet metadata of
                   Just (StylesheetPath fp)    -> UTF8.readFile fp
                   Just (StylesheetContents s) -> return s
                   Nothing -> UTF8.toString `fmap`
                              readDataFile (writerUserDataDir opts) "epub.css"
  let stylesheetEntry = mkEntry "stylesheet.css" $ UTF8.fromStringLazy stylesheet

  -- construct archive
  let archive = foldr addEntryToArchive emptyArchive
                 (mimetypeEntry : containerEntry : appleEntry : stylesheetEntry : tpEntry :
                  contentsEntry : tocEntry : navEntry :
                  (picEntries ++ cpicEntry ++ cpgEntry ++ chapterEntries ++ fontEntries))
  return $ fromArchive archive

metadataElement :: EPUBVersion -> EPUBMetadata -> UTCTime -> Element
metadataElement version md currentTime =
  unode "metadata" ! [("xmlns:dc","http://purl.org/dc/elements/1.1/")
                     ,("xmlns:opf","http://www.idpf.org/2007/opf")] $ mdNodes
  where mdNodes = identifierNodes ++ titleNodes ++ dateNodes ++ languageNodes
                  ++ creatorNodes ++ contributorNodes ++ subjectNodes
                  ++ descriptionNodes ++ typeNodes ++ formatNodes
                  ++ publisherNodes ++ sourceNodes ++ relationNodes
                  ++ coverageNodes ++ rightsNodes ++ coverImageNodes
                  ++ modifiedNodes
        withIds base f = concat . zipWith f (map (\x -> base ++ ('-' : show x))
                         ([1..] :: [Int]))
        identifierNodes = withIds "epub-id" toIdentifierNode $
                          epubIdentifier md
        titleNodes = withIds "epub-title" toTitleNode $ epubTitle md
        dateNodes = dcTag' "date" $ epubDate md
        languageNodes = [dcTag "language" $ epubLanguage md]
        creatorNodes = withIds "epub-creator" (toCreatorNode "creator") $
                       epubCreator md
        contributorNodes = withIds "epub-contributor"
                           (toCreatorNode "contributor") $ epubContributor md
        subjectNodes = map (dcTag "subject") $ epubSubject md
        descriptionNodes = maybe [] (dcTag' "description") $ epubDescription md
        typeNodes = maybe [] (dcTag' "type") $ epubType md
        formatNodes = maybe [] (dcTag' "format") $ epubFormat md
        publisherNodes = maybe [] (dcTag' "publisher") $ epubPublisher md
        sourceNodes = maybe [] (dcTag' "source") $ epubSource md
        relationNodes = maybe [] (dcTag' "relation") $ epubRelation md
        coverageNodes = maybe [] (dcTag' "coverage") $ epubCoverage md
        rightsNodes = maybe [] (dcTag' "rights") $ epubRights md
        coverImageNodes = maybe []
            (const $ [unode "meta" !  [("name","cover"),
                                       ("content","cover-image")] $ ()])
            $ epubCoverImage md
        modifiedNodes = [ unode "meta" ! [("property", "dcterms:modified")] $
               (showDateTimeISO8601 currentTime) | version == EPUB3 ]
        dcTag n s = unode ("dc:" ++ n) s
        dcTag' n s = [dcTag n s]
        toIdentifierNode id' (Identifier txt scheme)
          | version == EPUB2 = [dcNode "identifier" !
              ([("id",id')] ++ maybe [] (\x -> [("opf:scheme", x)]) scheme) $
              txt]
          | otherwise = [dcNode "identifier" ! [("id",id')] $ txt] ++
              maybe [] (\x -> [unode "meta" !
                  [("refines",'#':id'),("property","identifier-type"),
                   ("scheme","onix:codelist5")] $ x])
                (schemeToOnix `fmap` scheme)
        toCreatorNode s id' creator
          | version == EPUB2 = [dcNode s !
             ([("id",id')] ++
              maybe [] (\x -> [("opf:file-as",x)]) (creatorFileAs creator) ++
              maybe [] (\x -> [("opf:role",x)])
               (creatorRole creator >>= toRelator)) $ creatorText creator]
          | otherwise = [dcNode s ! [("id",id')] $ creatorText creator] ++
              maybe [] (\x -> [unode "meta" !
                   [("refines",'#':id'),("property","file-as")] $ x])
                   (creatorFileAs creator) ++
              maybe [] (\x -> [unode "meta" !
                   [("refines",'#':id'),("property","role"),
                     ("scheme","marc:relators")] $ x])
                   (creatorRole creator >>= toRelator)
        toTitleNode id' title
          | version == EPUB2 = [dcNode "title" !
             ([("id",id')] ++
              maybe [] (\x -> [("opf:file-as",x)]) (titleFileAs title) ++
              maybe [] (\x -> [("opf:title-type",x)]) (titleType title)) $
              titleText title]
          | otherwise = [dcNode "title" ! [("id",id')] $ titleText title]
              ++
              maybe [] (\x -> [unode "meta" !
                   [("refines",'#':id'),("property","file-as")] $ x])
                   (titleFileAs title) ++
              maybe [] (\x -> [unode "meta" !
                   [("refines",'#':id'),("property","title-type")] $ x])
                   (titleType title)
        schemeToOnix "ISBN-10" = "02"
        schemeToOnix "GTIN-13" = "03"
        schemeToOnix "UPC"     = "04"
        schemeToOnix "ISMN-10" = "05"
        schemeToOnix "DOI"     = "06"
        schemeToOnix "LCCN"    = "13"
        schemeToOnix "GTIN-14" = "14"
        schemeToOnix "ISBN-13" = "15"
        schemeToOnix "Legal deposit number" = "17"
        schemeToOnix "URN"     = "22"
        schemeToOnix "OCLC"    = "23"
        schemeToOnix "ISMN-13" = "25"
        schemeToOnix "ISBN-A"  = "26"
        schemeToOnix "JP"      = "27"
        schemeToOnix "OLCC"    = "28"
        schemeToOnix _         = "01"

showDateTimeISO8601 :: UTCTime -> String
showDateTimeISO8601 = formatTime defaultTimeLocale "%FT%TZ"

transformInline  :: WriterOptions
                 -> IORef [(FilePath, FilePath)] -- ^ (oldpath, newpath) images
                 -> Inline
                 -> IO Inline
transformInline opts picsRef (Image lab (src,tit)) = do
    let src' = unEscapeString src
    pics <- readIORef picsRef
    let oldsrc = maybe src' (</> src) $ writerSourceURL opts
    let ext = takeExtension src'
    newsrc <- case lookup oldsrc pics of
                    Just n  -> return n
                    Nothing -> do
                          let new = "images/img" ++ show (length pics) ++ ext
                          modifyIORef picsRef ( (oldsrc, new): )
                          return new
    return $ Image lab (newsrc, tit)
transformInline opts _ (x@(Math _ _))
  | WebTeX _ <- writerHTMLMathMethod opts = do
    raw <- makeSelfContained Nothing $ writeHtmlInline opts x
    return $ RawInline (Format "html") raw
transformInline _ _ x = return x

writeHtmlInline :: WriterOptions -> Inline -> String
writeHtmlInline opts z = trimr $
  writeHtmlString opts{ writerStandalone = False }
    $ Pandoc nullMeta [Plain [z]]

(!) :: Node t => (t -> Element) -> [(String, String)] -> t -> Element
(!) f attrs n = add_attrs (map (\(k,v) -> Attr (unqual k) v) attrs) (f n)

-- | Version of 'ppTopElement' that specifies UTF-8 encoding.
ppTopElement :: Element -> String
ppTopElement = ("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" ++) . unEntity . ppElement
  -- unEntity removes numeric  entities introduced by ppElement
  -- (kindlegen seems to choke on these).
  where unEntity [] = ""
        unEntity ('&':'#':xs) =
                   let (ds,ys) = break (==';') xs
                       rest = drop 1 ys
                   in  case safeRead ('\'':'\\':ds ++ "'") of
                          Just x   -> x : unEntity rest
                          Nothing  -> '&':'#':unEntity xs
        unEntity (x:xs) = x : unEntity xs

imageTypeOf :: FilePath -> Maybe String
imageTypeOf x = case getMimeType x of
                     Just y@('i':'m':'a':'g':'e':_) -> Just y
                     _                              -> Nothing

data IdentState = IdentState{
       chapterNumber :: Int,
       identTable    :: [(String,String)]
       } deriving (Read, Show)

-- Returns filename for chapter number.
showChapter :: Int -> String
showChapter = printf "ch%03d.xhtml"

-- Add identifiers to any headers without them.
addIdentifiers :: [Block] -> [Block]
addIdentifiers bs = evalState (mapM go bs) []
 where go (Header n (ident,classes,kvs) ils) = do
         ids <- get
         let ident' = if null ident
                         then uniqueIdent ils ids
                         else ident
         put $ ident' : ids
         return $ Header n (ident',classes,kvs) ils
       go x = return x

-- Go through a block list and construct a table
-- correlating the automatically constructed references
-- that would be used in a normal pandoc document with
-- new URLs to be used in the EPUB.  For example, what
-- was "header-1" might turn into "ch006.xhtml#header".
correlateRefs :: Int -> [Block] -> [(String,String)]
correlateRefs chapterHeaderLevel bs =
  identTable $ execState (mapM_ go bs)
    IdentState{ chapterNumber = 0
              , identTable = [] }
 where go :: Block -> State IdentState ()
       go (Header n (ident,_,_) _) = do
          when (n <= chapterHeaderLevel) $
              modify $ \s -> s{ chapterNumber = chapterNumber s + 1 }
          st <- get
          let chapterid = showChapter (chapterNumber st) ++
                          if n <= chapterHeaderLevel
                             then ""
                             else '#' : ident
          modify $ \s -> s{ identTable = (ident, chapterid) : identTable st }
       go _ = return ()

-- Replace internal link references using the table produced
-- by correlateRefs.
replaceRefs :: [(String,String)] -> [Block] -> [Block]
replaceRefs refTable = walk replaceOneRef
  where replaceOneRef x@(Link lab ('#':xs,tit)) =
          case lookup xs refTable of
                Just url -> Link lab (url,tit)
                Nothing  -> x
        replaceOneRef x = x

-- Variant of normalizeDate that allows partial dates: YYYY, YYYY-MM
normalizeDate' :: String -> Maybe String
normalizeDate' xs =
  let xs' = trim xs in
  case xs' of
       [y1,y2,y3,y4] | all isDigit [y1,y2,y3,y4] -> Just xs'     -- YYYY
       [y1,y2,y3,y4,'-',m1,m2] | all isDigit [y1,y2,y3,y4,m1,m2]  -- YYYY-MM
                                                 -> Just xs'
       _                                         -> normalizeDate xs'

toRelator :: String -> Maybe String
toRelator x
  | x `elem` relators = Just x
  | otherwise         = lookup (map toLower x) relatorMap

relators :: [String]
relators = map snd relatorMap

relatorMap :: [(String, String)]
relatorMap =
           [("abridger", "abr")
           ,("actor", "act")
           ,("adapter", "adp")
           ,("addressee", "rcp")
           ,("analyst", "anl")
           ,("animator", "anm")
           ,("annotator", "ann")
           ,("appellant", "apl")
           ,("appellee", "ape")
           ,("applicant", "app")
           ,("architect", "arc")
           ,("arranger", "arr")
           ,("art copyist", "acp")
           ,("art director", "adi")
           ,("artist", "art")
           ,("artistic director", "ard")
           ,("assignee", "asg")
           ,("associated name", "asn")
           ,("attributed name", "att")
           ,("auctioneer", "auc")
           ,("author", "aut")
           ,("author in quotations or text abstracts", "aqt")
           ,("author of afterword, colophon, etc.", "aft")
           ,("author of dialog", "aud")
           ,("author of introduction, etc.", "aui")
           ,("autographer", "ato")
           ,("bibliographic antecedent", "ant")
           ,("binder", "bnd")
           ,("binding designer", "bdd")
           ,("blurb writer", "blw")
           ,("book designer", "bkd")
           ,("book producer", "bkp")
           ,("bookjacket designer", "bjd")
           ,("bookplate designer", "bpd")
           ,("bookseller", "bsl")
           ,("braille embosser", "brl")
           ,("broadcaster", "brd")
           ,("calligrapher", "cll")
           ,("cartographer", "ctg")
           ,("caster", "cas")
           ,("censor", "cns")
           ,("choreographer", "chr")
           ,("cinematographer", "cng")
           ,("client", "cli")
           ,("collection registrar", "cor")
           ,("collector", "col")
           ,("collotyper", "clt")
           ,("colorist", "clr")
           ,("commentator", "cmm")
           ,("commentator for written text", "cwt")
           ,("compiler", "com")
           ,("complainant", "cpl")
           ,("complainant-appellant", "cpt")
           ,("complainant-appellee", "cpe")
           ,("composer", "cmp")
           ,("compositor", "cmt")
           ,("conceptor", "ccp")
           ,("conductor", "cnd")
           ,("conservator", "con")
           ,("consultant", "csl")
           ,("consultant to a project", "csp")
           ,("contestant", "cos")
           ,("contestant-appellant", "cot")
           ,("contestant-appellee", "coe")
           ,("contestee", "cts")
           ,("contestee-appellant", "ctt")
           ,("contestee-appellee", "cte")
           ,("contractor", "ctr")
           ,("contributor", "ctb")
           ,("copyright claimant", "cpc")
           ,("copyright holder", "cph")
           ,("corrector", "crr")
           ,("correspondent", "crp")
           ,("costume designer", "cst")
           ,("court governed", "cou")
           ,("court reporter", "crt")
           ,("cover designer", "cov")
           ,("creator", "cre")
           ,("curator", "cur")
           ,("dancer", "dnc")
           ,("data contributor", "dtc")
           ,("data manager", "dtm")
           ,("dedicatee", "dte")
           ,("dedicator", "dto")
           ,("defendant", "dfd")
           ,("defendant-appellant", "dft")
           ,("defendant-appellee", "dfe")
           ,("degree granting institution", "dgg")
           ,("delineator", "dln")
           ,("depicted", "dpc")
           ,("depositor", "dpt")
           ,("designer", "dsr")
           ,("director", "drt")
           ,("dissertant", "dis")
           ,("distribution place", "dbp")
           ,("distributor", "dst")
           ,("donor", "dnr")
           ,("draftsman", "drm")
           ,("dubious author", "dub")
           ,("editor", "edt")
           ,("editor of compilation", "edc")
           ,("editor of moving image work", "edm")
           ,("electrician", "elg")
           ,("electrotyper", "elt")
           ,("enacting jurisdiction", "enj")
           ,("engineer", "eng")
           ,("engraver", "egr")
           ,("etcher", "etr")
           ,("event place", "evp")
           ,("expert", "exp")
           ,("facsimilist", "fac")
           ,("field director", "fld")
           ,("film director", "fmd")
           ,("film distributor", "fds")
           ,("film editor", "flm")
           ,("film producer", "fmp")
           ,("filmmaker", "fmk")
           ,("first party", "fpy")
           ,("forger", "frg")
           ,("former owner", "fmo")
           ,("funder", "fnd")
           ,("geographic information specialist", "gis")
           ,("honoree", "hnr")
           ,("host", "hst")
           ,("host institution", "his")
           ,("illuminator", "ilu")
           ,("illustrator", "ill")
           ,("inscriber", "ins")
           ,("instrumentalist", "itr")
           ,("interviewee", "ive")
           ,("interviewer", "ivr")
           ,("inventor", "inv")
           ,("issuing body", "isb")
           ,("judge", "jud")
           ,("jurisdiction governed", "jug")
           ,("laboratory", "lbr")
           ,("laboratory director", "ldr")
           ,("landscape architect", "lsa")
           ,("lead", "led")
           ,("lender", "len")
           ,("libelant", "lil")
           ,("libelant-appellant", "lit")
           ,("libelant-appellee", "lie")
           ,("libelee", "lel")
           ,("libelee-appellant", "let")
           ,("libelee-appellee", "lee")
           ,("librettist", "lbt")
           ,("licensee", "lse")
           ,("licensor", "lso")
           ,("lighting designer", "lgd")
           ,("lithographer", "ltg")
           ,("lyricist", "lyr")
           ,("manufacture place", "mfp")
           ,("manufacturer", "mfr")
           ,("marbler", "mrb")
           ,("markup editor", "mrk")
           ,("metadata contact", "mdc")
           ,("metal-engraver", "mte")
           ,("moderator", "mod")
           ,("monitor", "mon")
           ,("music copyist", "mcp")
           ,("musical director", "msd")
           ,("musician", "mus")
           ,("narrator", "nrt")
           ,("onscreen presenter", "osp")
           ,("opponent", "opn")
           ,("organizer of meeting", "orm")
           ,("originator", "org")
           ,("other", "oth")
           ,("owner", "own")
           ,("panelist", "pan")
           ,("papermaker", "ppm")
           ,("patent applicant", "pta")
           ,("patent holder", "pth")
           ,("patron", "pat")
           ,("performer", "prf")
           ,("permitting agency", "pma")
           ,("photographer", "pht")
           ,("plaintiff", "ptf")
           ,("plaintiff-appellant", "ptt")
           ,("plaintiff-appellee", "pte")
           ,("platemaker", "plt")
           ,("praeses", "pra")
           ,("presenter", "pre")
           ,("printer", "prt")
           ,("printer of plates", "pop")
           ,("printmaker", "prm")
           ,("process contact", "prc")
           ,("producer", "pro")
           ,("production company", "prn")
           ,("production designer", "prs")
           ,("production manager", "pmn")
           ,("production personnel", "prd")
           ,("production place", "prp")
           ,("programmer", "prg")
           ,("project director", "pdr")
           ,("proofreader", "pfr")
           ,("provider", "prv")
           ,("publication place", "pup")
           ,("publisher", "pbl")
           ,("publishing director", "pbd")
           ,("puppeteer", "ppt")
           ,("radio director", "rdd")
           ,("radio producer", "rpc")
           ,("recording engineer", "rce")
           ,("recordist", "rcd")
           ,("redaktor", "red")
           ,("renderer", "ren")
           ,("reporter", "rpt")
           ,("repository", "rps")
           ,("research team head", "rth")
           ,("research team member", "rtm")
           ,("researcher", "res")
           ,("respondent", "rsp")
           ,("respondent-appellant", "rst")
           ,("respondent-appellee", "rse")
           ,("responsible party", "rpy")
           ,("restager", "rsg")
           ,("restorationist", "rsr")
           ,("reviewer", "rev")
           ,("rubricator", "rbr")
           ,("scenarist", "sce")
           ,("scientific advisor", "sad")
           ,("screenwriter", "aus")
           ,("scribe", "scr")
           ,("sculptor", "scl")
           ,("second party", "spy")
           ,("secretary", "sec")
           ,("seller", "sll")
           ,("set designer", "std")
           ,("setting", "stg")
           ,("signer", "sgn")
           ,("singer", "sng")
           ,("sound designer", "sds")
           ,("speaker", "spk")
           ,("sponsor", "spn")
           ,("stage director", "sgd")
           ,("stage manager", "stm")
           ,("standards body", "stn")
           ,("stereotyper", "str")
           ,("storyteller", "stl")
           ,("supporting host", "sht")
           ,("surveyor", "srv")
           ,("teacher", "tch")
           ,("technical director", "tcd")
           ,("television director", "tld")
           ,("television producer", "tlp")
           ,("thesis advisor", "ths")
           ,("transcriber", "trc")
           ,("translator", "trl")
           ,("type designer", "tyd")
           ,("typographer", "tyg")
           ,("university place", "uvp")
           ,("videographer", "vdg")
           ,("witness", "wit")
           ,("wood engraver", "wde")
           ,("woodcutter", "wdc")
           ,("writer of accompanying material", "wam")
           ,("writer of added commentary", "wac")
           ,("writer of added lyrics", "wal")
           ,("writer of added text", "wat")
           ]