aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Class.hs
blob: b053e9063acee74dec1c67ba3ef8f63b2516ccb9 (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
{-# LANGUAGE DeriveFunctor, DeriveDataTypeable, TypeSynonymInstances,
FlexibleInstances, GeneralizedNewtypeDeriving, FlexibleContexts,
StandaloneDeriving #-}

{-
Copyright (C) 2016 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.Class
   Copyright   : Copyright (C) 2016 Jesse Rosenthal
   License     : GNU GPL, version 2 or above

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

Typeclass for pandoc readers and writers, allowing both IO and pure instances.
-}

module Text.Pandoc.Class ( PandocMonad(..)
                         , CommonState(..)
                         , PureState(..)
                         , getPureState
                         , getsPureState
                         , putPureState
                         , modifyPureState
                         , getPOSIXTime
                         , getZonedTime
                         , readFileFromDirs
                         , report
                         , getLog
                         , setVerbosity
                         , getMediaBag
                         , setMediaBag
                         , insertMedia
                         , fetchItem
                         , getInputFiles
                         , getOutputFile
                         , setResourcePath
                         , getResourcePath
                         , PandocIO(..)
                         , PandocPure(..)
                         , FileTree(..)
                         , FileInfo(..)
                         , runIO
                         , runIOorExplode
                         , runPure
                         , withMediaBag
                         ) where

import Prelude hiding (readFile)
import System.Random (StdGen, next, mkStdGen)
import qualified System.Random as IO (newStdGen)
import Codec.Archive.Zip (Archive, fromArchive, emptyArchive)
import Data.Unique (hashUnique)
import qualified Data.Unique as IO (newUnique)
import qualified Text.Pandoc.Shared as IO ( readDataFile
                                          , openURL )
import qualified Text.Pandoc.UTF8 as UTF8
import Text.Pandoc.Compat.Time (UTCTime)
import Text.Pandoc.Logging
import Text.Parsec (ParsecT)
import qualified Text.Pandoc.Compat.Time as IO (getCurrentTime)
import Text.Pandoc.MIME (MimeType, getMimeType)
import Data.Time.Clock.POSIX ( utcTimeToPOSIXSeconds
                             , posixSecondsToUTCTime
                             , POSIXTime )
import Data.Time.LocalTime (TimeZone, ZonedTime, utcToZonedTime, utc)
import Network.URI ( escapeURIString, nonStrictRelativeTo,
                     unEscapeString, parseURIReference, isAllowedInURI,
                     parseURI, URI(..) )
import qualified Data.Time.LocalTime as IO (getCurrentTimeZone)
import Text.Pandoc.MediaBag (MediaBag, lookupMedia)
import qualified Text.Pandoc.MediaBag as MB
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL
import qualified System.Environment as IO (lookupEnv)
import System.FilePath.Glob (match, compile)
import System.FilePath ((</>), takeExtension, dropExtension, isRelative)
import qualified System.FilePath.Glob as IO (glob)
import qualified System.Directory as IO (getModificationTime)
import Control.Monad as M (fail)
import Control.Monad.Reader (ReaderT)
import Control.Monad.State
import Control.Monad.Except
import Control.Monad.Writer (WriterT)
import Control.Monad.RWS (RWST)
import Data.Word (Word8)
import Data.Default
import System.IO.Error
import System.IO (stderr)
import qualified Data.Map as M
import Text.Pandoc.Error
import Text.Printf (printf)

class (Functor m, Applicative m, Monad m, MonadError PandocError m)
      => PandocMonad m where
  lookupEnv :: String -> m (Maybe String)
  getCurrentTime :: m UTCTime
  getCurrentTimeZone :: m TimeZone
  newStdGen :: m StdGen
  newUniqueHash :: m Int
  openURL :: String -> m (B.ByteString, Maybe MimeType)
  readFileLazy :: FilePath -> m BL.ByteString
  readFileStrict :: FilePath -> m B.ByteString
  readDataFile :: Maybe FilePath -> FilePath -> m B.ByteString
  glob :: String -> m [FilePath]
  getModificationTime :: FilePath -> m UTCTime
  getCommonState :: m CommonState
  putCommonState :: CommonState -> m ()

  getsCommonState :: (CommonState -> a) -> m a
  getsCommonState f = f <$> getCommonState

  modifyCommonState :: (CommonState -> CommonState) -> m ()
  modifyCommonState f = getCommonState >>= putCommonState . f

  logOutput :: LogMessage -> m ()

-- Functions defined for all PandocMonad instances

setVerbosity :: PandocMonad m => Verbosity -> m ()
setVerbosity verbosity =
  modifyCommonState $ \st -> st{ stVerbosity = verbosity }

getLog :: PandocMonad m => m [LogMessage]
getLog = reverse <$> getsCommonState stLog

report :: PandocMonad m => LogMessage -> m ()
report msg = do
  verbosity <- getsCommonState stVerbosity
  let level = messageVerbosity msg
  when (level <= verbosity) $ do
    logOutput msg
  unless (level == DEBUG) $
    modifyCommonState $ \st -> st{ stLog = msg : stLog st }

setMediaBag :: PandocMonad m => MediaBag -> m ()
setMediaBag mb = modifyCommonState $ \st -> st{stMediaBag = mb}

getMediaBag :: PandocMonad m => m MediaBag
getMediaBag = getsCommonState stMediaBag

insertMedia :: PandocMonad m => FilePath -> Maybe MimeType -> BL.ByteString -> m ()
insertMedia fp mime bs = do
  mb <- getsCommonState stMediaBag
  let mb' = MB.insertMedia fp mime bs mb
  modifyCommonState $ \st -> st{stMediaBag = mb' }

getInputFiles :: PandocMonad m => m (Maybe [FilePath])
getInputFiles = getsCommonState stInputFiles

getOutputFile :: PandocMonad m => m (Maybe FilePath)
getOutputFile = getsCommonState stOutputFile

setResourcePath :: PandocMonad m => [FilePath] -> m ()
setResourcePath ps = modifyCommonState $ \st -> st{stResourcePath = ps}

getResourcePath :: PandocMonad m => m [FilePath]
getResourcePath = getsCommonState stResourcePath

getPOSIXTime :: (PandocMonad m) => m POSIXTime
getPOSIXTime = utcTimeToPOSIXSeconds <$> getCurrentTime

getZonedTime :: (PandocMonad m) => m ZonedTime
getZonedTime = do
  t <- getCurrentTime
  tz <- getCurrentTimeZone
  return $ utcToZonedTime tz t

-- | Read file, checking in any number of directories.
readFileFromDirs :: PandocMonad m => [FilePath] -> FilePath -> m (Maybe String)
readFileFromDirs [] _ = return Nothing
readFileFromDirs (d:ds) f = catchError
    ((Just . UTF8.toStringLazy) <$> readFileLazy (d </> f))
    (\_ -> readFileFromDirs ds f)

--

data CommonState = CommonState { stLog          :: [LogMessage]
                               , stMediaBag     :: MediaBag
                               , stInputFiles   :: Maybe [FilePath]
                               , stOutputFile   :: Maybe FilePath
                               , stResourcePath :: [FilePath]
                               , stVerbosity    :: Verbosity
                               }

instance Default CommonState where
  def = CommonState { stLog = []
                    , stMediaBag = mempty
                    , stInputFiles = Nothing
                    , stOutputFile = Nothing
                    , stResourcePath = ["."]
                    , stVerbosity = WARNING
                    }

runIO :: PandocIO a -> IO (Either PandocError a)
runIO ma = flip evalStateT def $ runExceptT $ unPandocIO ma

withMediaBag :: PandocMonad m => m a ->  m (a, MediaBag)
withMediaBag ma = ((,)) <$> ma <*> getMediaBag

runIOorExplode :: PandocIO a -> IO a
runIOorExplode ma = runIO ma >>= handleError

newtype PandocIO a = PandocIO {
  unPandocIO :: ExceptT PandocError (StateT CommonState IO) a
  } deriving ( MonadIO
             , Functor
             , Applicative
             , Monad
             , MonadError PandocError
             )

liftIOError :: (String -> IO a) -> String -> PandocIO a
liftIOError f u = do
  res <- liftIO $ tryIOError $ f u
  case res of
         Left e -> throwError $ PandocIOError u e
         Right r -> return r

instance PandocMonad PandocIO where
  lookupEnv = liftIO . IO.lookupEnv
  getCurrentTime = liftIO IO.getCurrentTime
  getCurrentTimeZone = liftIO IO.getCurrentTimeZone
  newStdGen = liftIO IO.newStdGen
  newUniqueHash = hashUnique <$> (liftIO IO.newUnique)
  openURL u = do
    report $ Fetching u
    liftIOError IO.openURL u
  readFileLazy s = liftIOError BL.readFile s
  readFileStrict s = liftIOError B.readFile s
  readDataFile mfp fname = liftIOError (IO.readDataFile mfp) fname
  glob = liftIO . IO.glob
  getModificationTime fp = liftIOError IO.getModificationTime fp
  getCommonState = PandocIO $ lift get
  putCommonState x = PandocIO $ lift $ put x
  logOutput msg =
    liftIO $ UTF8.hPutStrLn stderr $ printf "%-7s %s"
      (show (messageVerbosity msg)) (showLogMessage msg)

-- | Specialized version of parseURIReference that disallows
-- single-letter schemes.  Reason:  these are usually windows absolute
-- paths.
parseURIReference' :: String -> Maybe URI
parseURIReference' s =
  case parseURIReference s of
       Just u
         | length (uriScheme u) > 2  -> Just u
         | null (uriScheme u)        -> Just u  -- protocol-relative
       _                             -> Nothing

-- | Fetch an image or other item from the local filesystem or the net.
-- Returns raw content and maybe mime type.
fetchItem :: PandocMonad m
          => Maybe String
          -> String
          -> m (B.ByteString, Maybe MimeType)
fetchItem sourceURL s = do
  mediabag <- getMediaBag
  case lookupMedia s mediabag of
    Just (mime, bs) -> return $ (BL.toStrict bs, Just mime)
    Nothing -> downloadOrRead sourceURL s

downloadOrRead :: PandocMonad m
               => Maybe String
               -> String
               -> m (B.ByteString, Maybe MimeType)
downloadOrRead sourceURL s = do
  case (sourceURL >>= parseURIReference' .
                       ensureEscaped, ensureEscaped s) of
    (Just u, s') -> -- try fetching from relative path at source
       case parseURIReference' s' of
            Just u' -> openURL $ show $ u' `nonStrictRelativeTo` u
            Nothing -> openURL s' -- will throw error
    (Nothing, s'@('/':'/':_)) ->  -- protocol-relative URI
       case parseURIReference' s' of
            Just u' -> openURL $ show $ u' `nonStrictRelativeTo` httpcolon
            Nothing -> openURL s' -- will throw error
    (Nothing, s') ->
       case parseURI s' of  -- requires absolute URI
            -- We don't want to treat C:/ as a scheme:
            Just u' | length (uriScheme u') > 2 -> openURL (show u')
            Just u' | uriScheme u' == "file:" ->
                 readLocalFile $ dropWhile (=='/') (uriPath u')
            _ -> readLocalFile fp -- get from local file system
   where readLocalFile f = do
             resourcePath <- getResourcePath
             cont <- if isRelative f
                        then withPaths resourcePath readFileStrict f
                        else readFileStrict f
             return (cont, mime)
         httpcolon = URI{ uriScheme = "http:",
                          uriAuthority = Nothing,
                          uriPath = "",
                          uriQuery = "",
                          uriFragment = "" }
         dropFragmentAndQuery = takeWhile (\c -> c /= '?' && c /= '#')
         fp = unEscapeString $ dropFragmentAndQuery s
         mime = case takeExtension fp of
                     ".gz" -> getMimeType $ dropExtension fp
                     ".svgz" -> getMimeType $ dropExtension fp ++ ".svg"
                     x     -> getMimeType x
         ensureEscaped = escapeURIString isAllowedInURI . map convertSlash
         convertSlash '\\' = '/'
         convertSlash x    = x

withPaths :: PandocMonad m => [FilePath] -> (FilePath -> m a) -> FilePath -> m a
withPaths [] _ fp = throwError $ PandocIOError fp
                       (userError "file not found in resource path")
withPaths (p:ps) action fp =
  catchError (action (p </> fp))
             (\_ -> withPaths ps action fp)

data PureState = PureState { stStdGen     :: StdGen
                           , stWord8Store :: [Word8] -- should be
                                                     -- inifinite,
                                                     -- i.e. [1..]
                           , stUniqStore  :: [Int] -- should be
                                                   -- inifinite and
                                                   -- contain every
                                                   -- element at most
                                                   -- once, e.g. [1..]
                           , stEnv :: [(String, String)]
                           , stTime :: UTCTime
                           , stTimeZone :: TimeZone
                           , stReferenceDocx :: Archive
                           , stReferenceODT :: Archive
                           , stFiles :: FileTree
                           , stUserDataDir :: FileTree
                           , stCabalDataDir :: FileTree
                           , stFontFiles :: [FilePath]
                           }

instance Default PureState where
  def = PureState { stStdGen = mkStdGen 1848
                  , stWord8Store = [1..]
                  , stUniqStore = [1..]
                  , stEnv = [("USER", "pandoc-user")]
                  , stTime = posixSecondsToUTCTime 0
                  , stTimeZone = utc
                  , stReferenceDocx = emptyArchive
                  , stReferenceODT = emptyArchive
                  , stFiles = mempty
                  , stUserDataDir = mempty
                  , stCabalDataDir = mempty
                  , stFontFiles = []
                  }


getPureState :: PandocPure PureState
getPureState = PandocPure $ lift $ lift $ get

getsPureState :: (PureState -> a) -> PandocPure a
getsPureState f = f <$> getPureState

putPureState :: PureState -> PandocPure ()
putPureState ps= PandocPure $ lift $ lift $ put ps

modifyPureState :: (PureState -> PureState) -> PandocPure ()
modifyPureState f = PandocPure $ lift $ lift $ modify f


data FileInfo = FileInfo { infoFileMTime :: UTCTime
                         , infoFileContents :: B.ByteString
                         }

newtype FileTree = FileTree {unFileTree :: M.Map FilePath FileInfo}
  deriving (Monoid)

getFileInfo :: FilePath -> FileTree -> Maybe FileInfo
getFileInfo fp tree = M.lookup fp $ unFileTree tree


newtype PandocPure a = PandocPure {
  unPandocPure :: ExceptT PandocError
                  (StateT CommonState (State PureState)) a
  } deriving ( Functor
             , Applicative
             , Monad
             , MonadError PandocError
             )

runPure :: PandocPure a -> Either PandocError a
runPure x = flip evalState def $
            flip evalStateT def $
            runExceptT $
            unPandocPure x

instance PandocMonad PandocPure where
  lookupEnv s = do
    env <- getsPureState stEnv
    return (lookup s env)

  getCurrentTime = getsPureState stTime

  getCurrentTimeZone = getsPureState stTimeZone

  newStdGen = do
    g <- getsPureState stStdGen
    let (_, nxtGen) = next g
    modifyPureState $ \st -> st { stStdGen = nxtGen }
    return g

  newUniqueHash = do
    uniqs <- getsPureState stUniqStore
    case uniqs of
      u : us -> do
        modifyPureState $ \st -> st { stUniqStore = us }
        return u
      _ -> M.fail "uniq store ran out of elements"
  openURL u = throwError $ PandocIOError u $
                 userError "Cannot open URL in PandocPure"
  readFileLazy fp = do
    fps <- getsPureState stFiles
    case infoFileContents <$> getFileInfo fp fps of
      Just bs -> return (BL.fromStrict bs)
      Nothing -> throwError $ PandocIOError fp
                      (userError "File not found in PureState")
  readFileStrict fp = do
    fps <- getsPureState stFiles
    case infoFileContents <$> getFileInfo fp fps of
      Just bs -> return bs
      Nothing -> throwError $ PandocIOError fp
                       (userError "File not found in PureState")
  readDataFile Nothing "reference.docx" = do
    (B.concat . BL.toChunks . fromArchive) <$> getsPureState stReferenceDocx
  readDataFile Nothing "reference.odt" = do
    (B.concat . BL.toChunks . fromArchive) <$> getsPureState stReferenceODT
  readDataFile Nothing fname = do
    let fname' = if fname == "MANUAL.txt" then fname else "data" </> fname
    readFileStrict fname'
  readDataFile (Just userDir) fname = do
    userDirFiles <- getsPureState stUserDataDir
    case infoFileContents <$> (getFileInfo (userDir </> fname) userDirFiles) of
      Just bs -> return bs
      Nothing -> readDataFile Nothing fname

  glob s = do
    fontFiles <- getsPureState stFontFiles
    return (filter (match (compile s)) fontFiles)

  getModificationTime fp = do
    fps <- getsPureState stFiles
    case infoFileMTime <$> (getFileInfo fp fps) of
      Just tm -> return tm
      Nothing -> throwError $ PandocIOError fp
                    (userError "Can't get modification time")

  getCommonState = PandocPure $ lift $ get
  putCommonState x = PandocPure $ lift $ put x

  logOutput _msg = return ()

instance PandocMonad m => PandocMonad (ParsecT s st m) where
  lookupEnv = lift . lookupEnv
  getCurrentTime = lift getCurrentTime
  getCurrentTimeZone = lift getCurrentTimeZone
  newStdGen = lift newStdGen
  newUniqueHash = lift newUniqueHash
  openURL = lift . openURL
  readFileLazy = lift . readFileLazy
  readFileStrict = lift . readFileStrict
  readDataFile mbuserdir = lift . readDataFile mbuserdir
  glob = lift . glob
  getModificationTime = lift . getModificationTime
  getCommonState = lift getCommonState
  putCommonState = lift . putCommonState
  logOutput = lift . logOutput

instance PandocMonad m => PandocMonad (ReaderT r m) where
  lookupEnv = lift . lookupEnv
  getCurrentTime = lift getCurrentTime
  getCurrentTimeZone = lift getCurrentTimeZone
  newStdGen = lift newStdGen
  newUniqueHash = lift newUniqueHash
  openURL = lift . openURL
  readFileLazy = lift . readFileLazy
  readFileStrict = lift . readFileStrict
  readDataFile mbuserdir = lift . readDataFile mbuserdir
  glob = lift . glob
  getModificationTime = lift . getModificationTime
  getCommonState = lift getCommonState
  putCommonState = lift . putCommonState
  logOutput = lift . logOutput

instance (PandocMonad m, Monoid w) => PandocMonad (WriterT w m) where
  lookupEnv = lift . lookupEnv
  getCurrentTime = lift getCurrentTime
  getCurrentTimeZone = lift getCurrentTimeZone
  newStdGen = lift newStdGen
  newUniqueHash = lift newUniqueHash
  openURL = lift . openURL
  readFileLazy = lift . readFileLazy
  readFileStrict = lift . readFileStrict
  readDataFile mbuserdir = lift . readDataFile mbuserdir
  glob = lift . glob
  getModificationTime = lift . getModificationTime
  getCommonState = lift getCommonState
  putCommonState = lift . putCommonState
  logOutput = lift . logOutput

instance (PandocMonad m, Monoid w) => PandocMonad (RWST r w st m) where
  lookupEnv = lift . lookupEnv
  getCurrentTime = lift getCurrentTime
  getCurrentTimeZone = lift getCurrentTimeZone
  newStdGen = lift newStdGen
  newUniqueHash = lift newUniqueHash
  openURL = lift . openURL
  readFileLazy = lift . readFileLazy
  readFileStrict = lift . readFileStrict
  readDataFile mbuserdir = lift . readDataFile mbuserdir
  glob = lift . glob
  getModificationTime = lift . getModificationTime
  getCommonState = lift getCommonState
  putCommonState = lift . putCommonState
  logOutput = lift . logOutput

instance PandocMonad m => PandocMonad (StateT st m) where
  lookupEnv = lift . lookupEnv
  getCurrentTime = lift getCurrentTime
  getCurrentTimeZone = lift getCurrentTimeZone
  newStdGen = lift newStdGen
  newUniqueHash = lift newUniqueHash
  openURL = lift . openURL
  readFileLazy = lift . readFileLazy
  readFileStrict = lift . readFileStrict
  readDataFile mbuserdir = lift . readDataFile mbuserdir
  glob = lift . glob
  getModificationTime = lift . getModificationTime
  getCommonState = lift getCommonState
  putCommonState = lift . putCommonState
  logOutput = lift . logOutput