{-# LANGUAGE OverloadedStrings #-}
  | 
    Module       : Text . Pandoc . Readers . Docx . Fields 
    Copyright    : Copyright ( C ) 2014 - 2020   
    License      : GNU GPL , version 2 or above 

    Maintainer   :   <  > 
    Stability    : alpha 
    Portability : portable 

 For parsing Field definitions in instText tags , as described in 
 ECMA-376 - 1:2016 , § 17.16.5
   Module      : Text.Pandoc.Readers.Docx.Fields
   Copyright   : Copyright (C) 2014-2020 Jesse Rosenthal
   License     : GNU GPL, version 2 or above

   Maintainer  : Jesse Rosenthal <>
   Stability   : alpha
   Portability : portable

For parsing Field definitions in instText tags, as described in
ECMA-376-1:2016, §17.16.5 -}

module Text.Pandoc.Readers.Docx.Fields ( FieldInfo(..)
                                       , parseFieldInfo
                                       ) where

import Data.Functor (($>), void)
import qualified Data.Text as T
import Text.Parsec
import Text.Parsec.Text (Parser)

type URL = T.Text

data FieldInfo = HyperlinkField URL
               | UnknownField
               deriving (Show)

parseFieldInfo :: T.Text -> Either ParseError FieldInfo
parseFieldInfo = parse fieldInfo ""

fieldInfo :: Parser FieldInfo
fieldInfo =
  try (HyperlinkField <$> hyperlink)
  <|>
  return UnknownField

escapedQuote :: Parser T.Text
escapedQuote = string "\\\"" $> "\\\""

inQuotes :: Parser T.Text
inQuotes =
  try escapedQuote <|> (T.singleton <$> anyChar)

quotedString :: Parser T.Text
quotedString = do
  char '"'
  T.concat <$> manyTill inQuotes (try (char '"'))

unquotedString :: Parser T.Text
unquotedString = T.pack <$> manyTill anyChar (try $ void (lookAhead space) <|> eof)

fieldArgument :: Parser T.Text
fieldArgument = quotedString <|> unquotedString

  there are other switches , but this is the only one I 've seen in the wild so far , so it 's the first one I 'll implement . See § 17.16.5.25
hyperlinkSwitch :: Parser (T.Text, T.Text)
hyperlinkSwitch = do
  sw <- string "\\l"
  spaces
  farg <- fieldArgument
  return (T.pack sw, farg)

hyperlink :: Parser URL
hyperlink = do
  many space
  string "HYPERLINK"
  spaces
  farg <- fieldArgument
  switches <- spaces *> many hyperlinkSwitch
  let url = case switches of
              ("\\l", s) : _ -> farg <> "#" <> s
              _              -> farg
  return url

# LANGUAGE OverloadedStrings #
  | 
    Module       : Text . Pandoc . Readers . Docx . Fields 
    Copyright    : Copyright ( C ) 2014 - 2020   
    License      : GNU GPL , version 2 or above 

    Maintainer   :   <  > 
    Stability    : alpha 
    Portability : portable 

 For parsing Field definitions in instText tags , as described in 
 ECMA-376 - 1:2016 , § 17.16.5
   Module      : Text.Pandoc.Readers.Docx.Fields
   Copyright   : Copyright (C) 2014-2020 Jesse Rosenthal
   License     : GNU GPL, version 2 or above

   Maintainer  : Jesse Rosenthal <>
   Stability   : alpha
   Portability : portable

For parsing Field definitions in instText tags, as described in
ECMA-376-1:2016, §17.16.5 -}

module Text.Pandoc.Readers.Docx.Fields ( FieldInfo(..)
                                       , parseFieldInfo
                                       ) where

import Data.Functor (($>), void)
import qualified Data.Text as T
import Text.Parsec
import Text.Parsec.Text (Parser)

type URL = T.Text

data FieldInfo = HyperlinkField URL
               | UnknownField
               deriving (Show)

parseFieldInfo :: T.Text -> Either ParseError FieldInfo
parseFieldInfo = parse fieldInfo ""

fieldInfo :: Parser FieldInfo
fieldInfo =
  try (HyperlinkField <$> hyperlink)
  <|>
  return UnknownField

escapedQuote :: Parser T.Text
escapedQuote = string "\\\"" $> "\\\""

inQuotes :: Parser T.Text
inQuotes =
  try escapedQuote <|> (T.singleton <$> anyChar)

quotedString :: Parser T.Text
quotedString = do
  char '"'
  T.concat <$> manyTill inQuotes (try (char '"'))

unquotedString :: Parser T.Text
unquotedString = T.pack <$> manyTill anyChar (try $ void (lookAhead space) <|> eof)

fieldArgument :: Parser T.Text
fieldArgument = quotedString <|> unquotedString

  there are other switches , but this is the only one I 've seen in the wild so far , so it 's the first one I 'll implement . See § 17.16.5.25
hyperlinkSwitch :: Parser (T.Text, T.Text)
hyperlinkSwitch = do
  sw <- string "\\l"
  spaces
  farg <- fieldArgument
  return (T.pack sw, farg)

hyperlink :: Parser URL
hyperlink = do
  many space
  string "HYPERLINK"
  spaces
  farg <- fieldArgument
  switches <- spaces *> many hyperlinkSwitch
  let url = case switches of
              ("\\l", s) : _ -> farg <> "#" <> s
              _              -> farg
  return url
