aboutsummaryrefslogtreecommitdiff
path: root/src/pandoc.hs
blob: 0560efc0a32546c0c1c1148bf225958595fef16c (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
{-
Copyright (C) 2006-2010 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      : Main
   Copyright   : Copyright (C) 2006-2010 John MacFarlane
   License     : GNU GPL, version 2 or above

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

Parses command-line options and calls the appropriate readers and
writers.
-}
module Main where
import Text.Pandoc
import Text.Pandoc.ODT
import Text.Pandoc.Writers.S5 (s5HeaderIncludes)
import Text.Pandoc.Shared ( tabFilter, ObfuscationMethod (..), readDataFile )
#ifdef _HIGHLIGHTING
import Text.Pandoc.Highlighting ( languages )
#endif
import System.Environment ( getArgs, getProgName, getEnvironment )
import System.Exit ( exitWith, ExitCode (..) )
import System.FilePath
import System.Console.GetOpt
import Data.Maybe ( fromMaybe )
import Data.Char ( toLower, isDigit )
import Data.List ( intercalate, isSuffixOf )
import System.Directory ( getAppUserDataDirectory )
import System.IO ( stdout, stderr )
-- Note: ghc >= 6.12 (base >=4.2) supports unicode through iconv
-- So we use System.IO.UTF8 only if we have an earlier version
#if MIN_VERSION_base(4,2,0)
import System.IO ( hPutStr, hPutStrLn )
#else
import Prelude hiding ( putStr, putStrLn, writeFile, readFile, getContents )
import System.IO.UTF8
#endif
#ifdef _CITEPROC
import Text.CSL
import Text.Pandoc.Biblio
#endif
import Control.Monad (when, unless, liftM)
import Network.HTTP (simpleHTTP, mkRequest, getResponseBody, RequestMethod(..))
import Network.URI (parseURI, isURI)
import Data.ByteString.Lazy.UTF8 (toString)

copyrightMessage :: String
copyrightMessage = "\nCopyright (C) 2006-2010 John MacFarlane\n" ++
                    "Web:  http://johnmacfarlane.net/pandoc\n" ++
                    "This is free software; see the source for copying conditions.  There is no\n" ++
                    "warranty, not even for merchantability or fitness for a particular purpose."

compileInfo :: String
compileInfo =
#ifdef _CITEPROC
  "\nCompiled with citeproc support." ++
#endif
#ifdef _HIGHLIGHTING
   "\nCompiled with syntax highlighting support for:\n" ++
       wrapWords 78 languages ++
#endif
   ""

-- | Converts a list of strings into a single string with the items printed as
-- comma separated words in lines with a maximum line length.
wrapWords :: Int -> [String] -> String
wrapWords c = wrap' c c where
              wrap' _    _         []     = ""
              wrap' cols remaining (x:xs) = if remaining == cols
                                               then x ++ wrap' cols (remaining - length x) xs
                                               else if (length x + 1) > remaining
                                                       then ",\n" ++ x ++ wrap' cols (cols - length x) xs
                                                       else ", "  ++ x ++ wrap' cols (remaining - (length x + 2)) xs

-- | Association list of formats and readers.
readers :: [(String, ParserState -> String -> Pandoc)]
readers = [("native"       , readPandoc)
          ,("markdown"     , readMarkdown)
          ,("markdown+lhs" , readMarkdown)
          ,("rst"          , readRST)
          ,("rst+lhs"      , readRST)
          ,("html"         , readHtml)
          ,("latex"        , readLaTeX)
          ,("latex+lhs"    , readLaTeX)
          ]

-- | Reader for native Pandoc format.
readPandoc :: ParserState -> String -> Pandoc
readPandoc _ = read

-- | Association list of formats and writers.
writers :: [ ( String, WriterOptions -> Pandoc -> String ) ]
writers = [("native"       , writeDoc)
          ,("html"         , writeHtmlString)
          ,("html+lhs"     , writeHtmlString)
          ,("s5"           , writeS5String)
          ,("docbook"      , writeDocbook)
          ,("opendocument" , writeOpenDocument)
          ,("odt"          , writeOpenDocument)
          ,("latex"        , writeLaTeX)
          ,("latex+lhs"    , writeLaTeX)
          ,("context"      , writeConTeXt)
          ,("texinfo"      , writeTexinfo)
          ,("man"          , writeMan)
          ,("markdown"     , writeMarkdown)
          ,("markdown+lhs" , writeMarkdown)
          ,("plain"        , writePlain)
          ,("rst"          , writeRST)
          ,("rst+lhs"      , writeRST)
          ,("mediawiki"    , writeMediaWiki)
          ,("rtf"          , writeRTF)
          ]

isNonTextOutput :: String -> Bool
isNonTextOutput = (`elem` ["odt"])

-- | Writer for Pandoc native format.
writeDoc :: WriterOptions -> Pandoc -> String
writeDoc _ = prettyPandoc

headerShift :: Int -> Pandoc -> Pandoc
headerShift n = processWith shift
  where shift :: Block -> Block
        shift (Header level inner) = Header (level + n) inner
        shift x                    = x

-- | Data structure for command line options.
data Opt = Opt
    { optTabStop           :: Int     -- ^ Number of spaces per tab
    , optPreserveTabs      :: Bool    -- ^ Preserve tabs instead of converting to spaces
    , optStandalone        :: Bool    -- ^ Include header, footer
    , optReader            :: String  -- ^ Reader format
    , optWriter            :: String  -- ^ Writer format
    , optParseRaw          :: Bool    -- ^ Parse unconvertable HTML and TeX
    , optTableOfContents   :: Bool    -- ^ Include table of contents
    , optTransforms        :: [Pandoc -> Pandoc]  -- ^ Doc transforms to apply
    , optTemplate          :: String  -- ^ Custom template
    , optVariables         :: [(String,String)] -- ^ Template variables to set
    , optBefore            :: [String] -- ^ Texts to include before body
    , optAfter             :: [String] -- ^ Texts to include after body
    , optOutputFile        :: String  -- ^ Name of output file
    , optNumberSections    :: Bool    -- ^ Number sections in LaTeX
    , optIncremental       :: Bool    -- ^ Use incremental lists in S5
    , optXeTeX             :: Bool    -- ^ Format latex for xetex
    , optSmart             :: Bool    -- ^ Use smart typography
    , optHTMLMathMethod    :: HTMLMathMethod -- ^ Method to print HTML math
    , optReferenceODT      :: Maybe FilePath -- ^ Path of reference.odt
    , optDumpArgs          :: Bool    -- ^ Output command-line arguments
    , optIgnoreArgs        :: Bool    -- ^ Ignore command-line arguments
    , optStrict            :: Bool    -- ^ Use strict markdown syntax
    , optReferenceLinks    :: Bool    -- ^ Use reference links in writing markdown, rst
    , optWrapText          :: Bool    -- ^ Wrap text
    , optSanitizeHTML      :: Bool    -- ^ Sanitize HTML
    , optPlugins           :: [Pandoc -> IO Pandoc] -- ^ Plugins to apply
    , optEmailObfuscation  :: ObfuscationMethod
    , optIdentifierPrefix  :: String
    , optIndentedCodeClasses :: [String] -- ^ Default classes for indented code blocks
    , optDataDir           :: Maybe FilePath
#ifdef _CITEPROC
    , optBiblioFile        :: String
    , optBiblioFormat      :: String
    , optCslFile           :: String
#endif
    }

-- | Defaults for command-line options.
defaultOpts :: Opt
defaultOpts = Opt
    { optTabStop           = 4
    , optPreserveTabs      = False
    , optStandalone        = False
    , optReader            = ""    -- null for default reader
    , optWriter            = ""    -- null for default writer
    , optParseRaw          = False
    , optTableOfContents   = False
    , optTransforms        = []
    , optTemplate          = ""
    , optVariables         = []
    , optBefore            = []
    , optAfter             = []
    , optOutputFile        = "-"    -- "-" means stdout
    , optNumberSections    = False
    , optIncremental       = False
    , optXeTeX             = False
    , optSmart             = False
    , optHTMLMathMethod    = PlainMath
    , optReferenceODT      = Nothing
    , optDumpArgs          = False
    , optIgnoreArgs        = False
    , optStrict            = False
    , optReferenceLinks    = False
    , optWrapText          = True
    , optSanitizeHTML      = False
    , optPlugins           = []
    , optEmailObfuscation  = JavascriptObfuscation
    , optIdentifierPrefix  = ""
    , optIndentedCodeClasses = []
    , optDataDir           = Nothing
#ifdef _CITEPROC
    , optBiblioFile        = []
    , optBiblioFormat      = []
    , optCslFile           = []
#endif
    }

-- | A list of functions, each transforming the options data structure
--   in response to a command-line option.
options :: [OptDescr (Opt -> IO Opt)]
options =
    [ Option "fr" ["from","read"]
                 (ReqArg
                  (\arg opt -> return opt { optReader = map toLower arg })
                  "FORMAT")
                 "" -- ("(" ++ (intercalate ", " $ map fst readers) ++ ")")

    , Option "tw" ["to","write"]
                 (ReqArg
                  (\arg opt -> return opt { optWriter = map toLower arg })
                  "FORMAT")
                 "" -- ("(" ++ (intercalate ", " $ map fst writers) ++ ")")

    , Option "s" ["standalone"]
                 (NoArg
                  (\opt -> return opt { optStandalone = True }))
                 "" -- "Include needed header and footer on output"

    , Option "o" ["output"]
                 (ReqArg
                  (\arg opt -> return opt { optOutputFile = arg })
                  "FILENAME")
                 "" -- "Name of output file"

    , Option "p" ["preserve-tabs"]
                 (NoArg
                  (\opt -> return opt { optPreserveTabs = True }))
                 "" -- "Preserve tabs instead of converting to spaces"

    , Option "" ["tab-stop"]
                 (ReqArg
                  (\arg opt -> return opt { optTabStop = (read arg) } )
                  "TABSTOP")
                 "" -- "Tab stop (default 4)"

    , Option "" ["strict"]
                 (NoArg
                  (\opt -> return opt { optStrict = True } ))
                 "" -- "Disable markdown syntax extensions"

    , Option "" ["reference-links"]
                 (NoArg
                  (\opt -> return opt { optReferenceLinks = True } ))
                 "" -- "Use reference links in parsing HTML"

    , Option "R" ["parse-raw"]
                 (NoArg
                  (\opt -> return opt { optParseRaw = True }))
                 "" -- "Parse untranslatable HTML codes and LaTeX environments as raw"

    , Option "S" ["smart"]
                 (NoArg
                  (\opt -> return opt { optSmart = True }))
                 "" -- "Use smart quotes, dashes, and ellipses"

    , Option "m" ["latexmathml", "asciimathml"]
                 (OptArg
                  (\arg opt ->
                      return opt { optHTMLMathMethod = LaTeXMathML arg })
                  "URL")
                 "" -- "Use LaTeXMathML script in html output"

    , Option "" ["mathml"]
                 (OptArg
                  (\arg opt ->
                      return opt { optHTMLMathMethod = MathML arg })
                   "URL")
                 "" -- "Use mathml for HTML math"

    , Option "" ["mimetex"]
                 (OptArg
                  (\arg opt -> return opt { optHTMLMathMethod = MimeTeX
                                  (fromMaybe "/cgi-bin/mimetex.cgi" arg)})
                  "URL")
                 "" -- "Use mimetex for HTML math"

    , Option "" ["jsmath"]
                 (OptArg
                  (\arg opt -> return opt { optHTMLMathMethod = JsMath arg})
                  "URL")
                 "" -- "Use jsMath for HTML math"

    , Option "" ["gladtex"]
                 (NoArg
                  (\opt -> return opt { optHTMLMathMethod = GladTeX }))
                 "" -- "Use gladtex for HTML math"

    , Option "i" ["incremental"]
                 (NoArg
                  (\opt -> return opt { optIncremental = True }))
                 "" -- "Make list items display incrementally in S5"

    , Option "" ["xetex"]
                 (NoArg
                  (\opt -> return opt { optXeTeX = True }))
                 "" -- "Format latex for processing by XeTeX"

    , Option "N" ["number-sections"]
                 (NoArg
                  (\opt -> return opt { optNumberSections = True }))
                 "" -- "Number sections in LaTeX"

    , Option "" ["no-wrap"]
                 (NoArg
                  (\opt -> return opt { optWrapText = False }))
                 "" -- "Do not wrap text in output"

    , Option "" ["sanitize-html"]
                 (NoArg
                  (\opt -> return opt { optSanitizeHTML = True }))
                 "" -- "Sanitize HTML"

    , Option "" ["email-obfuscation"]
                 (ReqArg
                  (\arg opt -> do
                     method <- case arg of
                            "references" -> return ReferenceObfuscation
                            "javascript" -> return JavascriptObfuscation
                            "none"       -> return NoObfuscation
                            _            -> hPutStrLn stderr ("Error: Unknown obfuscation method: " ++ arg) >>
                                            exitWith (ExitFailure 6)
                     return opt { optEmailObfuscation = method })
                  "none|javascript|references")
                 "" -- "Method for obfuscating email in HTML"

     , Option "" ["id-prefix"]
                  (ReqArg
                   (\arg opt -> return opt { optIdentifierPrefix = arg })
                   "STRING")
                  "" -- "Prefix to add to automatically generated HTML identifiers"

     , Option "" ["indented-code-classes"]
                  (ReqArg
                   (\arg opt -> return opt { optIndentedCodeClasses = words $
                                             map (\c -> if c == ',' then ' ' else c) arg })
                   "STRING")
                  "" -- "Classes (whitespace- or comma-separated) to use for indented code-blocks"

    , Option "" ["toc", "table-of-contents"]
                (NoArg
                 (\opt -> return opt { optTableOfContents = True }))
               "" -- "Include table of contents"

    , Option "" ["base-header-level"]
                 (ReqArg
                  (\arg opt -> do
                     if all isDigit arg && (read arg :: Int) >= 1
                        then do
                           let oldTransforms = optTransforms opt
                           let shift = read arg - 1
                           return opt{ optTransforms =
                                         headerShift shift : oldTransforms }
                        else do
                           hPutStrLn stderr $ "base-header-level must be a number >= 1"
                           exitWith $ ExitFailure 19)
                  "LEVEL")
                 "" -- "Headers base level"

    , Option "" ["template"]
                 (ReqArg
                  (\arg opt -> do
                     text <- readFile arg
                     return opt{ optTemplate = text,
                                 optStandalone = True })
                  "FILENAME")
                 "" -- "Use custom template"

    , Option "V" ["variable"]
                 (ReqArg
                  (\arg opt ->
                     case break (`elem` ":=") arg of
                          (k,_:v) -> do
                            let newvars = optVariables opt ++ [(k,v)]
                            return opt{ optVariables = newvars }
                          _  -> do
                            hPutStrLn stderr $ "Could not parse `" ++ arg ++ "' as a key/value pair (k=v or k:v)"
                            exitWith $ ExitFailure 17)
                  "FILENAME")
                 "" -- "Use custom template"

    , Option "c" ["css"]
                 (ReqArg
                  (\arg opt -> do
                     -- add new link to end, so it is included in proper order
                     let newvars = optVariables opt ++ [("css",arg)]
                     return opt { optVariables = newvars,
                                  optStandalone = True })
                  "URL")
                 "" -- "Link to CSS style sheet"

    , Option "H" ["include-in-header"]
                 (ReqArg
                  (\arg opt -> do
                     text <- readFile arg
                     -- add new ones to end, so they're included in order specified
                     let newvars = optVariables opt ++ [("header-includes",text)]
                     return opt { optVariables = newvars,
                                  optStandalone = True })
                  "FILENAME")
                 "" -- "File to include at end of header (implies -s)"

    , Option "B" ["include-before-body"]
                 (ReqArg
                  (\arg opt -> do
                     text <- readFile arg
                     -- add new ones to end, so they're included in order specified
                     let newvars = optVariables opt ++ [("include-before",text)]
                     return opt { optVariables = newvars,
                                  optStandalone = True })
                  "FILENAME")
                 "" -- "File to include before document body"

    , Option "A" ["include-after-body"]
                 (ReqArg
                  (\arg opt -> do
                     text <- readFile arg
                     -- add new ones to end, so they're included in order specified
                     let newvars = optVariables opt ++ [("include-after",text)]
                     return opt { optVariables = newvars,
                                  optStandalone = True })
                  "FILENAME")
                 "" -- "File to include after document body"

    , Option "C" ["custom-header"]
                 (ReqArg
                  (\arg opt -> do
                     text <- readFile arg
                     let newVars = ("legacy-header", text) : optVariables opt
                     return opt { optVariables = newVars
                                , optStandalone = True })
                  "FILENAME")
                 "" -- "File to use for custom header (implies -s)"

    , Option "T" ["title-prefix"]
                 (ReqArg
                  (\arg opt -> do
                    let newvars = ("title-prefix", arg) : optVariables opt
                    return opt { optVariables = newvars,
                                 optStandalone = True })
                  "STRING")
                 "" -- "String to prefix to HTML window title"

    , Option "" ["reference-odt"]
                 (ReqArg
                  (\arg opt -> do
                    return opt { optReferenceODT = Just arg })
                  "FILENAME")
                 "" -- "Path of custom reference.odt"

    , Option "D" ["print-default-template"]
                 (ReqArg
                  (\arg _ -> do
                     templ <- getDefaultTemplate Nothing arg
                     case templ of
                          Right t -> hPutStr stdout t
                          Left e  -> error $ show e
                     exitWith ExitSuccess)
                  "FORMAT")
                 "" -- "Print default template for FORMAT"
#ifdef _CITEPROC
    , Option "" ["biblio"]
                 (ReqArg
                  (\arg opt -> return opt { optBiblioFile = arg} )
                  "FILENAME")
                 ""
    , Option "" ["biblio-format"]
                 (ReqArg
                  (\arg opt -> return opt { optBiblioFormat = arg} )
                  "STRING")
                 ""
    , Option "" ["csl"]
                 (ReqArg
                  (\arg opt -> return opt { optCslFile = arg} )
                  "FILENAME")
                 ""
#endif
    , Option "" ["data-dir"]
                 (ReqArg
                  (\arg opt -> return opt { optDataDir = Just arg })
                 "DIRECTORY") -- "Directory containing pandoc data files."
                ""

    , Option "" ["dump-args"]
                 (NoArg
                  (\opt -> return opt { optDumpArgs = True }))
                 "" -- "Print output filename and arguments to stdout."

    , Option "" ["ignore-args"]
                 (NoArg
                  (\opt -> return opt { optIgnoreArgs = True }))
                 "" -- "Ignore command-line arguments."

    , Option "v" ["version"]
                 (NoArg
                  (\_ -> do
                     prg <- getProgName
                     hPutStrLn stdout (prg ++ " " ++ pandocVersion ++ compileInfo ++
                                       copyrightMessage)
                     exitWith ExitSuccess ))
                 "" -- "Print version"

    , Option "h" ["help"]
                 (NoArg
                  (\_ -> do
                     prg <- getProgName
                     hPutStr stdout (usageMessage prg options)
                     exitWith ExitSuccess ))
                 "" -- "Show help"
    ]

-- Returns usage message
usageMessage :: String -> [OptDescr (Opt -> IO Opt)] -> String
usageMessage programName = usageInfo
  (programName ++ " [OPTIONS] [FILES]" ++ "\nInput formats:  " ++
  (intercalate ", " $ map fst readers) ++ "\nOutput formats:  " ++
  (intercalate ", " $ map fst writers) ++ "\nOptions:")

-- Determine default reader based on source file extensions
defaultReaderName :: String -> [FilePath] -> String
defaultReaderName fallback [] = fallback
defaultReaderName fallback (x:xs) =
  case takeExtension (map toLower x) of
    ".xhtml"    -> "html"
    ".html"     -> "html"
    ".htm"      -> "html"
    ".tex"      -> "latex"
    ".latex"    -> "latex"
    ".ltx"      -> "latex"
    ".rst"      -> "rst"
    ".lhs"      -> "markdown+lhs"
    ".native"   -> "native"
    _           -> defaultReaderName fallback xs

-- Returns True if extension of first source is .lhs
lhsExtension :: [FilePath] -> Bool
lhsExtension (x:_) = takeExtension x == ".lhs"
lhsExtension _ = False

-- Determine default writer based on output file extension
defaultWriterName :: FilePath -> String
defaultWriterName "-" = "html" -- no output file
defaultWriterName x =
  case takeExtension (map toLower x) of
    ""          -> "markdown" -- empty extension
    ".tex"      -> "latex"
    ".latex"    -> "latex"
    ".ltx"      -> "latex"
    ".context"  -> "context"
    ".ctx"      -> "context"
    ".rtf"      -> "rtf"
    ".rst"      -> "rst"
    ".s5"       -> "s5"
    ".native"   -> "native"
    ".txt"      -> "markdown"
    ".text"     -> "markdown"
    ".md"       -> "markdown"
    ".markdown" -> "markdown"
    ".lhs"      -> "markdown+lhs"
    ".texi"     -> "texinfo"
    ".texinfo"  -> "texinfo"
    ".db"       -> "docbook"
    ".odt"      -> "odt"
    ['.',y] | y `elem` ['1'..'9'] -> "man"
    _          -> "html"

main :: IO ()
main = do

  rawArgs <- getArgs
  prg <- getProgName
  let compatMode = (prg == "hsmarkdown")

  let (actions, args, errors) = if compatMode
                                  then ([], rawArgs, [])
                                  else getOpt Permute options rawArgs

  unless (null errors) $
    do name <- getProgName
       mapM_ (\e -> hPutStr stderr (name ++ ": ") >> hPutStr stderr e) errors
       hPutStrLn stderr $ "Try " ++ name ++ " --help for more information."
       exitWith $ ExitFailure 2

  let defaultOpts' = if compatMode
                       then defaultOpts { optReader = "markdown"
                                        , optWriter = "html"
                                        , optStrict = True }
                       else defaultOpts

  -- thread option data structure through all supplied option actions
  opts <- foldl (>>=) (return defaultOpts') actions

  let Opt    {  optTabStop           = tabStop
              , optPreserveTabs      = preserveTabs
              , optStandalone        = standalone
              , optReader            = readerName
              , optWriter            = writerName
              , optParseRaw          = parseRaw
              , optVariables         = variables
              , optBefore            = befores
              , optAfter             = afters
              , optTableOfContents   = toc
              , optTransforms        = transforms
              , optTemplate          = template
              , optOutputFile        = outputFile
              , optNumberSections    = numberSections
              , optIncremental       = incremental
              , optXeTeX             = xetex
              , optSmart             = smart
              , optHTMLMathMethod    = mathMethod
              , optReferenceODT      = referenceODT
              , optDumpArgs          = dumpArgs
              , optIgnoreArgs        = ignoreArgs
              , optStrict            = strict
              , optReferenceLinks    = referenceLinks
              , optWrapText          = wrap
              , optSanitizeHTML      = sanitize
              , optEmailObfuscation  = obfuscationMethod
              , optIdentifierPrefix  = idPrefix
              , optIndentedCodeClasses = codeBlockClasses
              , optDataDir           = mbDataDir
#ifdef _CITEPROC
              , optBiblioFile         = biblioFile
              , optBiblioFormat       = biblioFormat
              , optCslFile            = cslFile
#endif
             } = opts

  when dumpArgs $
    do hPutStrLn stdout outputFile
       mapM_ (\arg -> hPutStrLn stdout arg) args
       exitWith ExitSuccess

  -- warn about deprecated options
  case lookup "legacy-header" variables of
     Just _  -> hPutStrLn stderr $
       "Warning: The -C/--custom-header is deprecated.\n" ++
       "Please transition to using --template instead."
     Nothing -> return ()

  let sources = if ignoreArgs then [] else args

  datadir <- case mbDataDir of
                  Nothing   -> catch
                                 (liftM Just $ getAppUserDataDirectory "pandoc")
                                 (const $ return Nothing)
                  Just _    -> return mbDataDir

  -- assign reader and writer based on options and filenames
  let readerName' = if null readerName
                      then let fallback = if any isURI sources
                                             then "html"
                                             else "markdown"
                           in  defaultReaderName fallback sources
                      else readerName 

  let writerName' = if null writerName
                      then defaultWriterName outputFile
                      else writerName

  reader <- case (lookup readerName' readers) of
     Just r  -> return r
     Nothing -> error ("Unknown reader: " ++ readerName')

  writer <- case (lookup writerName' writers) of
     Just r  -> return r
     Nothing -> error ("Unknown writer: " ++ writerName')

  templ <- getDefaultTemplate datadir writerName'
  let defaultTemplate = case templ of
                             Right t -> t
                             Left  e -> error (show e)

  environment <- getEnvironment
  let columns = case lookup "COLUMNS" environment of
                 Just cols -> read cols
                 Nothing   -> stateColumns defaultParserState

  let standalone' = standalone || isNonTextOutput writerName'

#ifdef _CITEPROC
  refs <- if null biblioFile then return [] else readBiblioFile biblioFile biblioFormat
#endif

  variables' <- if writerName' == "s5" && standalone'
                   then do
                     inc <- s5HeaderIncludes datadir
                     return $ ("header-includes", inc) : variables
                   else return variables

  variables'' <- case mathMethod of
                      LaTeXMathML Nothing -> do
                         s <- readDataFile datadir $ "data" </> "LaTeXMathML.js"
                         return $ ("mathml-script", s) : variables'
                      MathML Nothing -> do
                         s <- readDataFile datadir $ "data"</>"MathMLinHTML.js"
                         return $ ("mathml-script", s) : variables'
                      _ -> return variables'

  let startParserState =
         defaultParserState { stateParseRaw        = parseRaw,
                              stateTabStop         = tabStop,
                              stateSanitizeHTML    = sanitize,
                              stateLiterateHaskell = "+lhs" `isSuffixOf` readerName' ||
                                                     lhsExtension sources,
                              stateStandalone      = standalone',
#ifdef _CITEPROC
                              stateCitations       = map citeKey refs,
#endif
                              stateSmart           = smart || writerName' `elem`
                                                              ["latex", "context", "man"],
                              stateColumns         = columns,
                              stateStrict          = strict,
                              stateIndentedCodeClasses = codeBlockClasses }
  let writerOptions = WriterOptions { writerStandalone       = standalone',
                                      writerTemplate         = if null template
                                                                  then defaultTemplate
                                                                  else template,
                                      writerVariables        = variables'',
                                      writerIncludeBefore    = concat befores,
                                      writerIncludeAfter     = concat afters,
                                      writerTabStop          = tabStop,
                                      writerTableOfContents  = toc &&
                                                               writerName' /= "s5",
                                      writerHTMLMathMethod   = mathMethod,
                                      writerS5               = (writerName' == "s5"),
                                      writerXeTeX            = xetex,
                                      writerIgnoreNotes      = False,
                                      writerIncremental      = incremental,
                                      writerNumberSections   = numberSections,
                                      writerStrictMarkdown   = strict,
                                      writerReferenceLinks   = referenceLinks,
                                      writerWrapText         = wrap,
                                      writerLiterateHaskell  = "+lhs" `isSuffixOf` writerName' ||
                                                               lhsExtension [outputFile],
                                      writerEmailObfuscation = if strict
                                                                  then ReferenceObfuscation
                                                                  else obfuscationMethod,
                                      writerIdentifierPrefix = idPrefix }

  when (isNonTextOutput writerName' && outputFile == "-") $
    do hPutStrLn stderr ("Error:  Cannot write " ++ writerName ++ " output to stdout.\n" ++
                               "Specify an output file using the -o option.")
       exitWith $ ExitFailure 5

  let sourceDirRelative = if null sources
                             then ""
                             else takeDirectory (head sources)

  let readSources [] = mapM readSource ["-"]
      readSources srcs = mapM readSource srcs
      readSource "-" = getContents
      readSource src = case parseURI src of
                            Just u  -> readURI u
                            Nothing -> readFile src
      readURI uri = simpleHTTP (mkRequest GET uri) >>= getResponseBody >>=
                      return . toString  -- treat all as UTF8

  let convertTabs = tabFilter (if preserveTabs then 0 else tabStop)

  doc <- fmap (reader startParserState . convertTabs . intercalate "\n") (readSources sources)

  let doc' = foldr ($) doc transforms

  doc'' <- do
#ifdef _CITEPROC
          processBiblio cslFile refs doc'
#else
          return doc'
#endif

  let writerOutput = writer writerOptions doc'' ++ "\n"

  case writerName' of
       "odt"   -> saveOpenDocumentAsODT datadir outputFile sourceDirRelative referenceODT writerOutput
       _       -> if outputFile == "-"
                     then putStr writerOutput
                     else writeFile outputFile writerOutput