aboutsummaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/Readers/DokuWiki.hs
blob: 60d406df118944c77fa93a58d1c78fd97e724d2e (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
{-# LANGUAGE FlexibleContexts  #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TupleSections     #-}
{- |
   Module      : Text.Pandoc.Readers.DokuWiki
   Copyright   : Copyright (C) 2018-2019 Alexander Krotov
   License     : GNU GPL, version 2 or above

   Maintainer  : Alexander Krotov <ilabdsf@gmail.com>
   Stability   : alpha
   Portability : portable

Conversion of DokuWiki text to 'Pandoc' document.
-}
module Text.Pandoc.Readers.DokuWiki (readDokuWiki) where

import Prelude
import Control.Monad
import Control.Monad.Except (throwError)
import Data.Char (isAlphaNum, isDigit)
import qualified Data.Foldable as F
import Data.List (intercalate, transpose, isPrefixOf, isSuffixOf)
import Data.List.Split (splitOn)
import Data.Maybe (fromMaybe, catMaybes)
import Data.Text (Text)
import qualified Data.Text as T
import qualified Text.Pandoc.Builder as B
import Text.Pandoc.Class (PandocMonad (..))
import Text.Pandoc.Definition
import Text.Pandoc.Error (PandocError (PandocParsecError))
import Text.Pandoc.Options
import Text.Pandoc.Parsing hiding (enclosed, nested)
import Text.Pandoc.Shared (crFilter, trim, underlineSpan)

-- | Read DokuWiki from an input string and return a Pandoc document.
readDokuWiki :: PandocMonad m
             => ReaderOptions
             -> Text
             -> m Pandoc
readDokuWiki opts s = do
  let input = crFilter s
  res <- runParserT parseDokuWiki def {stateOptions = opts } "source" input
  case res of
       Left e  -> throwError $ PandocParsecError (T.unpack input) e
       Right d -> return d

type DWParser = ParserT Text ParserState

-- * Utility functions

-- | Parse end-of-line, which can be either a newline or end-of-file.
eol :: Stream s m Char => ParserT s st m ()
eol = void newline <|> eof

nested :: PandocMonad m => DWParser m a -> DWParser m a
nested p = do
  nestlevel <- stateMaxNestingLevel <$>  getState
  guard $ nestlevel > 0
  updateState $ \st -> st{ stateMaxNestingLevel = stateMaxNestingLevel st - 1 }
  res <- p
  updateState $ \st -> st{ stateMaxNestingLevel = nestlevel }
  return res

guardColumnOne :: PandocMonad m => DWParser m ()
guardColumnOne = getPosition >>= \pos -> guard (sourceColumn pos == 1)

-- | Parse DokuWiki document.
parseDokuWiki :: PandocMonad m => DWParser m Pandoc
parseDokuWiki =
  B.doc . mconcat <$> many block <* spaces <* eof

-- | Parse <code> and <file> attributes
codeLanguage :: PandocMonad m => DWParser m (String, [String], [(String, String)])
codeLanguage = try $ do
  rawLang <- option "-" (spaceChar *> manyTill anyChar (lookAhead (spaceChar <|> char '>')))
  let attr = case rawLang of
               "-" -> []
               l -> [l]
  return ("", attr, [])

-- | Generic parser for <code> and <file> tags
codeTag :: PandocMonad m
        => ((String, [String], [(String, String)]) -> String -> a)
        -> String
        -> DWParser m a
codeTag f tag = try $ f
  <$  char '<'
  <*  string tag
  <*> codeLanguage
  <*  manyTill anyChar (char '>')
  <*  optional (manyTill spaceChar eol)
  <*> manyTill anyChar (try $ string "</" <* string tag <* char '>')

-- * Inline parsers

-- | Parse any inline element but softbreak.
inline' :: PandocMonad m => DWParser m B.Inlines
inline' = whitespace
      <|> br
      <|> bold
      <|> italic
      <|> underlined
      <|> nowiki
      <|> percent
      <|> link
      <|> image
      <|> monospaced
      <|> subscript
      <|> superscript
      <|> deleted
      <|> footnote
      <|> inlineCode
      <|> inlineFile
      <|> inlineHtml
      <|> inlinePhp
      <|> autoLink
      <|> autoEmail
      <|> notoc
      <|> nocache
      <|> str
      <|> symbol
      <?> "inline"

-- | Parse any inline element, including soft break.
inline :: PandocMonad m => DWParser m B.Inlines
inline = endline <|> inline'

endline :: PandocMonad m => DWParser m B.Inlines
endline = try $ B.softbreak <$ skipMany spaceChar <* linebreak

whitespace :: PandocMonad m => DWParser m B.Inlines
whitespace = try $ B.space <$ skipMany1 spaceChar

br :: PandocMonad m => DWParser m B.Inlines
br = try $ B.linebreak <$ string "\\\\" <* space

linebreak :: PandocMonad m => DWParser m B.Inlines
linebreak = newline >> notFollowedBy newline >> (lastNewline <|> innerNewline)
  where lastNewline  = mempty <$ eof
        innerNewline = pure B.space

between :: (Monoid c, PandocMonad m, Show b)
        => DWParser m a -> DWParser m b -> (DWParser m b -> DWParser m c)
        -> DWParser m c
between start end p =
  mconcat <$> try (start >> notFollowedBy whitespace >> many1Till (p end) end)

enclosed :: (Monoid b, PandocMonad m, Show a)
         => DWParser m a -> (DWParser m a -> DWParser m b) -> DWParser m b
enclosed sep p = between sep (try sep) p

nestedInlines :: (Show a, PandocMonad m)
              => DWParser m a -> DWParser m B.Inlines
nestedInlines end = innerSpace <|> nestedInline
  where
    innerSpace   = try $ whitespace <* notFollowedBy end
    nestedInline = notFollowedBy whitespace >> nested inline

bold :: PandocMonad m => DWParser m B.Inlines
bold = try $ B.strong <$> enclosed (string "**") nestedInlines

italic :: PandocMonad m => DWParser m B.Inlines
italic = try $ B.emph <$> enclosed (string "//") nestedInlines

underlined :: PandocMonad m => DWParser m B.Inlines
underlined = try $ underlineSpan <$> enclosed (string "__") nestedInlines

nowiki :: PandocMonad m => DWParser m B.Inlines
nowiki = try $ B.text <$ string "<nowiki>" <*> manyTill anyChar (try $ string "</nowiki>")

percent :: PandocMonad m => DWParser m B.Inlines
percent = try $ B.text <$> enclosed (string "%%") nestedString

nestedString :: (Show a, PandocMonad m)
             => DWParser m a -> DWParser m String
nestedString end = innerSpace <|> count 1 nonspaceChar
  where
    innerSpace = try $ many1 spaceChar <* notFollowedBy end

monospaced :: PandocMonad m => DWParser m B.Inlines
monospaced = try $ B.code <$> enclosed (string "''") nestedString

subscript :: PandocMonad m => DWParser m B.Inlines
subscript = try $ B.subscript <$> between (string "<sub>") (try $ string "</sub>") nestedInlines

superscript :: PandocMonad m => DWParser m B.Inlines
superscript = try $ B.superscript <$> between (string "<sup>") (try $ string "</sup>") nestedInlines

deleted :: PandocMonad m => DWParser m B.Inlines
deleted = try $ B.strikeout <$> between (string "<del>") (try $ string "</del>") nestedInlines

-- | Parse a footnote.
footnote :: PandocMonad m => DWParser m B.Inlines
footnote = try $ B.note . B.para <$> between (string "((") (try $ string "))") nestedInlines

inlineCode :: PandocMonad m => DWParser m B.Inlines
inlineCode = codeTag B.codeWith "code"

inlineFile :: PandocMonad m => DWParser m B.Inlines
inlineFile = codeTag B.codeWith "file"

inlineHtml :: PandocMonad m => DWParser m B.Inlines
inlineHtml = try $ B.rawInline "html" <$ string "<html>" <*> manyTill anyChar (try $ string "</html>")

inlinePhp :: PandocMonad m => DWParser m B.Inlines
inlinePhp = try $ B.codeWith ("", ["php"], []) <$ string "<php>" <*> manyTill anyChar (try $ string "</php>")

makeLink :: (String, String) -> B.Inlines
makeLink (text, url) = B.link url "" $ B.str text

autoEmail :: PandocMonad m => DWParser m B.Inlines
autoEmail = try $ do
  state <- getState
  guard $ stateAllowLinks state
  makeLink <$ char '<' <*> emailAddress <* char '>'

autoLink :: PandocMonad m => DWParser m B.Inlines
autoLink = try $ do
  state <- getState
  guard $ stateAllowLinks state
  (text, url) <- uri
  guard $ checkLink (last url)
  return $ makeLink (text, url)
  where
    checkLink c
      | c == '/' = True
      | otherwise = isAlphaNum c

notoc :: PandocMonad m => DWParser m B.Inlines
notoc = try $ mempty <$ string "~~NOTOC~~"

nocache :: PandocMonad m => DWParser m B.Inlines
nocache = try $ mempty <$ string "~~NOCACHE~~"

str :: PandocMonad m => DWParser m B.Inlines
str = B.str <$> (many1 alphaNum <|> count 1 characterReference)

symbol :: PandocMonad m => DWParser m B.Inlines
symbol = B.str <$> count 1 nonspaceChar

link :: PandocMonad m => DWParser m B.Inlines
link = try $ do
  st <- getState
  guard $ stateAllowLinks st
  setState $ st{ stateAllowLinks = False }
  l <- linkText
  setState $ st{ stateAllowLinks = True }
  return l

isExternalLink :: String -> Bool
isExternalLink s =
  case dropWhile (\c -> isAlphaNum c || (c `elem` ['-', '.', '+'])) s of
    (':':'/':'/':_) -> True
    _ -> False

isAbsolutePath :: String -> Bool
isAbsolutePath ('.':_) = False
isAbsolutePath s = ':' `elem` s

normalizeDots :: String -> String
normalizeDots path@('.':_) =
  case dropWhile (== '.') path of
    ':':_ -> path
    _ -> takeWhile (== '.') path ++ ':':dropWhile (== '.') path
normalizeDots path = path

normalizeInternalPath :: String -> String
normalizeInternalPath path =
  if isAbsolutePath path
    then ensureAbsolute normalizedPath
    else normalizedPath
  where
    normalizedPath = intercalate "/" $ dropWhile (== ".") $ splitOn ":" $ normalizeDots path
    ensureAbsolute s@('/':_) = s
    ensureAbsolute s = '/':s

normalizePath :: String -> String
normalizePath path =
  if isExternalLink path
    then path
    else normalizeInternalPath path

urlToText :: String -> String
urlToText url =
  if isExternalLink url
    then url
    else reverse $ takeWhile (/= ':') $ reverse url

-- Parse link or image
parseLink :: PandocMonad m
          => (String -> Maybe B.Inlines -> B.Inlines)
          -> String
          -> String
          -> DWParser m B.Inlines
parseLink f l r = f
  <$  string l
  <*> many1Till anyChar (lookAhead (void (char '|') <|> try (void $ string r)))
  <*> optionMaybe (B.trimInlines . mconcat <$> (char '|' *> manyTill inline (try $ lookAhead $ string r)))
  <*  string r

-- | Split Interwiki link into left and right part
-- | Return Nothing if it is not Interwiki link
splitInterwiki :: String -> Maybe (String, String)
splitInterwiki path =
  case span (\c -> isAlphaNum c || c == '.') path of
    (l, '>':r) -> Just (l, r)
    _ -> Nothing

interwikiToUrl :: String -> String -> String
interwikiToUrl "callto" page = "callto://" ++ page
interwikiToUrl "doku" page = "https://www.dokuwiki.org/" ++ page
interwikiToUrl "phpfn" page = "https://secure.php.net/" ++ page
interwikiToUrl "tel" page = "tel:" ++ page
interwikiToUrl "wp" page = "https://en.wikipedia.org/wiki/" ++ page
interwikiToUrl "wpde" page = "https://de.wikipedia.org/wiki/" ++ page
interwikiToUrl "wpes" page = "https://es.wikipedia.org/wiki/" ++ page
interwikiToUrl "wpfr" page = "https://fr.wikipedia.org/wiki/" ++ page
interwikiToUrl "wpjp" page = "https://jp.wikipedia.org/wiki/" ++ page
interwikiToUrl "wppl" page = "https://pl.wikipedia.org/wiki/" ++ page
interwikiToUrl _ page = "https://www.google.com/search?q=" ++ page ++ "&btnI=lucky"

linkText :: PandocMonad m => DWParser m B.Inlines
linkText = parseLink fromRaw "[[" "]]"
  where
    fromRaw path description =
      B.link normalizedPath "" (fromMaybe (B.str defaultDescription) description)
      where
        path' = trim path
        interwiki = splitInterwiki path'
        normalizedPath =
          case interwiki of
            Nothing -> normalizePath path'
            Just (l, r) -> interwikiToUrl l r
        defaultDescription =
          case interwiki of
            Nothing -> urlToText path'
            Just (_, r) -> r

-- Matches strings like "100x100" (width x height) and "50" (width)
isWidthHeightParameter :: String -> Bool
isWidthHeightParameter s =
  case s of
    (x:xs) ->
      isDigit x && case dropWhile isDigit xs of
                     ('x':ys@(_:_)) -> all isDigit ys
                     "" -> True
                     _ -> False
    _ -> False

parseWidthHeight :: String -> (Maybe String, Maybe String)
parseWidthHeight s = (width, height)
  where
    width = Just $ takeWhile isDigit s
    height =
      case dropWhile isDigit s of
        ('x':xs) -> Just xs
        _ -> Nothing

image :: PandocMonad m => DWParser m B.Inlines
image = try $ parseLink fromRaw "{{" "}}"
  where
    fromRaw path description =
      if linkOnly
        then B.link normalizedPath "" (fromMaybe defaultDescription description)
        else B.imageWith ("", classes, attributes) normalizedPath "" (fromMaybe defaultDescription description)
      where
        (path', parameters) = span (/= '?') $ trim path
        normalizedPath = normalizePath path'
        leftPadding = " " `isPrefixOf` path
        rightPadding = " " `isSuffixOf` path
        classes =
          case (leftPadding, rightPadding) of
            (False, False) -> []
            (False, True) -> ["align-left"]
            (True, False) -> ["align-right"]
            (True, True) -> ["align-center"]
        parameterList = splitOn "&" $ drop 1 parameters
        linkOnly = "linkonly" `elem` parameterList
        (width, height) = maybe (Nothing, Nothing) parseWidthHeight (F.find isWidthHeightParameter parameterList)
        attributes = catMaybes [fmap ("width",) width, fmap ("height",) height]
        defaultDescription = B.str $ urlToText path'

-- * Block parsers

block :: PandocMonad m => DWParser m B.Blocks
block = do
  res <- mempty <$ skipMany1 blankline
         <|> blockElements
         <|> para
  skipMany blankline
  trace (take 60 $ show $ B.toList res)
  return res

blockElements :: PandocMonad m => DWParser m B.Blocks
blockElements = horizontalLine
            <|> header
            <|> list "  "
            <|> indentedCode
            <|> quote
            <|> blockCode
            <|> blockFile
            <|> blockHtml
            <|> blockPhp
            <|> table

horizontalLine :: PandocMonad m => DWParser m B.Blocks
horizontalLine = try $ B.horizontalRule <$ string "---" <* many1 (char '-') <* eol

header :: PandocMonad m => DWParser m B.Blocks
header = try $ do
  guardColumnOne
  eqs <- many1 (char '=')
  let lev = length eqs
  guard $ lev < 7
  contents <- B.trimInlines . mconcat <$> manyTill inline (try $ char '=' *> many1 (char '='))
  attr <- registerHeader nullAttr contents
  return $ B.headerWith attr (7 - lev) contents

list :: PandocMonad m => String -> DWParser m B.Blocks
list prefix = bulletList prefix <|> orderedList prefix

bulletList :: PandocMonad m => String -> DWParser m B.Blocks
bulletList prefix = try $ B.bulletList <$> parseList prefix '*'

orderedList :: PandocMonad m => String -> DWParser m B.Blocks
orderedList prefix = try $ B.orderedList <$> parseList prefix '-'

parseList :: PandocMonad m
          => String
          -> Char
          -> DWParser m [B.Blocks]
parseList prefix marker =
  many1 ((<>) <$> item <*> fmap mconcat (many continuation))
  where
    continuation = try $ list ("  " ++ prefix)
    item = try $ string prefix *> char marker *> char ' ' *> itemContents
    itemContents = B.plain . mconcat <$> many1Till inline' eol

indentedCode :: PandocMonad m => DWParser m B.Blocks
indentedCode = try $ B.codeBlock . unlines <$> many1 indentedLine
 where
   indentedLine = try $ string "  " *> manyTill anyChar eol

quote :: PandocMonad m => DWParser m B.Blocks
quote = try $ nestedQuote 0
  where
    prefix level = count level (char '>')
    contents level = nestedQuote level <|> quoteLine
    quoteLine = try $ B.plain . B.trimInlines . mconcat <$> many1Till inline' eol
    quoteContents level = (<>) <$> contents level <*> quoteContinuation level
    quoteContinuation level = mconcat <$> many (try $ prefix level *> contents level)
    nestedQuote level = B.blockQuote <$ char '>' <*> quoteContents (level + 1 :: Int)

blockHtml :: PandocMonad m => DWParser m B.Blocks
blockHtml = try $ B.rawBlock "html"
  <$  string "<HTML>"
  <*  optional (manyTill spaceChar eol)
  <*> manyTill anyChar (try $ string "</HTML>")

blockPhp :: PandocMonad m => DWParser m B.Blocks
blockPhp = try $ B.codeBlockWith ("", ["php"], [])
  <$  string "<PHP>"
  <*  optional (manyTill spaceChar eol)
  <*> manyTill anyChar (try $ string "</PHP>")

table :: PandocMonad m => DWParser m B.Blocks
table = do
  firstSeparator <- lookAhead tableCellSeparator
  rows <- tableRows
  let (headerRow, body) = if firstSeparator == '^'
                            then (head rows, tail rows)
                            else ([], rows)
  let attrs = const (AlignDefault, 0.0) <$> transpose rows
  pure $ B.table mempty attrs headerRow body

tableRows :: PandocMonad m => DWParser m [[B.Blocks]]
tableRows = many1 tableRow

tableRow :: PandocMonad m => DWParser m [B.Blocks]
tableRow = many1Till tableCell tableRowEnd

tableRowEnd :: PandocMonad m => DWParser m Char
tableRowEnd = try $ tableCellSeparator <* manyTill spaceChar eol

tableCellSeparator :: PandocMonad m => DWParser m Char
tableCellSeparator = char '|' <|> char '^'

tableCell :: PandocMonad m => DWParser m B.Blocks
tableCell = try $ B.plain . B.trimInlines . mconcat <$> (normalCell <|> headerCell)
  where
    normalCell = char '|' *> manyTill inline' (lookAhead tableCellSeparator)
    headerCell = char '^' *> manyTill inline' (lookAhead tableCellSeparator)

blockCode :: PandocMonad m => DWParser m B.Blocks
blockCode = codeTag B.codeBlockWith "code"

blockFile :: PandocMonad m => DWParser m B.Blocks
blockFile = codeTag B.codeBlockWith "file"

para :: PandocMonad m => DWParser m B.Blocks
para = result . mconcat <$> many1Till inline endOfParaElement
 where
   endOfParaElement = lookAhead $ endOfInput <|> endOfPara <|> newBlockElement
   endOfInput       = try $ skipMany blankline >> skipSpaces >> eof
   endOfPara        = try $ blankline >> skipMany1 blankline
   newBlockElement  = try $ blankline >> void blockElements
   result content   = if F.all (==Space) content
                      then mempty
                      else B.para $ B.trimInlines content