Class: generalize PandocIO functions to MonadIO

1 files changed, 21 insertions, 167 deletions

diff --git a/src/Text/Pandoc/Class/PandocIO.hs b/src/Text/Pandoc/Class/PandocIO.hs
index ee6a041ba..63cb94155 100644
--- a/src/Text/Pandoc/Class/PandocIO.hs
+++ b/src/Text/Pandoc/Class/PandocIO.hs
@@ -1,7 +1,5 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE OverloadedStrings #-}
 {- |
 Module      : Text.Pandoc.Class.PandocIO
 Copyright   : Copyright (C) 2016-2020 Jesse Rosenthal, John MacFarlane
@@ -16,79 +14,21 @@ This module defines @'PandocIO'@, an IO-based instance of the
 using IO operators.
 -}
 module Text.Pandoc.Class.PandocIO
-  ( getPOSIXTime
-  , getZonedTime
-  , readFileFromDirs
-  , report
-  , setTrace
-  , setRequestHeader
-  , getLog
-  , setVerbosity
-  , getVerbosity
-  , getMediaBag
-  , setMediaBag
-  , insertMedia
-  , setUserDataDir
-  , getUserDataDir
-  , fetchItem
-  , getInputFiles
-  , setInputFiles
-  , getOutputFile
-  , setOutputFile
-  , setResourcePath
-  , getResourcePath
-  , PandocIO(..)
+  ( PandocIO(..)
   , runIO
   , runIOorExplode
   , extractMedia
  ) where
 
-import Control.Monad.Except
-import Control.Monad.State.Strict
-import Data.ByteString.Base64 (decodeLenient)
-import Data.ByteString.Lazy (toChunks)
-import Data.Default
-import Data.Text (Text)
-import Data.Unique (hashUnique)
-import Network.HTTP.Client
-       (httpLbs, responseBody, responseHeaders,
-        Request(port, host, requestHeaders), parseRequest, newManager)
-import Network.HTTP.Client.Internal (addProxy)
-import Network.HTTP.Client.TLS (mkManagerSettings)
-import Network.Connection (TLSSettings (..))
-import Network.HTTP.Types.Header ( hContentType )
-import Network.Socket (withSocketsDo)
-import Network.URI ( unEscapeString )
-import Prelude
-import System.Directory (createDirectoryIfMissing)
-import System.Environment (getEnv)
-import System.FilePath ((</>), takeDirectory, normalise)
-import System.IO (stderr)
-import System.IO.Error
+import Control.Monad.Except (ExceptT, MonadError, runExceptT)
+import Control.Monad.IO.Class (MonadIO)
+import Control.Monad.State (StateT, evalStateT, lift, get, put)
+import Data.Default (Default (def))
 import Text.Pandoc.Class.CommonState (CommonState (..))
 import Text.Pandoc.Class.PandocMonad
 import Text.Pandoc.Definition
 import Text.Pandoc.Error
-import Text.Pandoc.Logging
-import Text.Pandoc.MediaBag (MediaBag, lookupMedia, mediaDirectory)
-import Text.Pandoc.Walk (walk)
-import qualified Control.Exception as E
-import qualified Data.ByteString as B
-import qualified Data.ByteString.Lazy as BL
-import qualified Data.CaseInsensitive as CI
-import qualified Data.Text as T
-import qualified Data.Time as IO (getCurrentTime)
-import qualified Data.Time.LocalTime as IO (getCurrentTimeZone)
-import qualified Data.Unique as IO (newUnique)
-import qualified System.Directory as Directory
-import qualified System.Directory as IO (getModificationTime)
-import qualified System.Environment as IO (lookupEnv)
-import qualified System.FilePath.Glob as IO (glob)
-import qualified System.Random as IO (newStdGen)
-import qualified Text.Pandoc.UTF8 as UTF8
-#ifndef EMBED_DATA_FILES
-import qualified Paths_pandoc as Paths
-#endif
+import qualified Text.Pandoc.Class.IO as IO
 
 -- | Evaluate a 'PandocIO' operation.
 runIO :: PandocIO a -> IO (Either PandocError a)
@@ -108,113 +48,27 @@ newtype PandocIO a = PandocIO {
              , MonadError PandocError
              )
 
--- | Utility function to lift IO errors into 'PandocError's.
-liftIOError :: (String -> IO a) -> String -> PandocIO a
-liftIOError f u = do
-  res <- liftIO $ tryIOError $ f u
-  case res of
-         Left e  -> throwError $ PandocIOError (T.pack u) e
-         Right r -> return r
-
--- | Show potential IO errors to the user continuing execution anyway
-logIOError :: IO () -> PandocIO ()
-logIOError f = do
-  res <- liftIO $ tryIOError f
-  case res of
-    Left e -> report $ IgnoredIOError $ T.pack $ E.displayException e
-    Right _ -> pure ()
-
 instance PandocMonad PandocIO where
-  lookupEnv = fmap (fmap T.pack) . liftIO . IO.lookupEnv . T.unpack
-  getCurrentTime = liftIO IO.getCurrentTime
-  getCurrentTimeZone = liftIO IO.getCurrentTimeZone
-  newStdGen = liftIO IO.newStdGen
-  newUniqueHash = hashUnique <$> liftIO IO.newUnique
-
-  openURL u
-   | Just u'' <- T.stripPrefix "data:" u = do
-       let mime     = T.takeWhile (/=',') u''
-       let contents = UTF8.fromString $
-                       unEscapeString $ T.unpack $ T.drop 1 $ T.dropWhile (/=',') u''
-       return (decodeLenient contents, Just mime)
-   | otherwise = do
-       let toReqHeader (n, v) = (CI.mk (UTF8.fromText n), UTF8.fromText v)
-       customHeaders <- map toReqHeader <$> getsCommonState stRequestHeaders
-       disableCertificateValidation <- getsCommonState stNoCheckCertificate
-       report $ Fetching u
-       res <- liftIO $ E.try $ withSocketsDo $ do
-         let parseReq = parseRequest
-         proxy <- tryIOError (getEnv "http_proxy")
-         let addProxy' x = case proxy of
-                              Left _ -> return x
-                              Right pr -> parseReq pr >>= \r ->
-                                  return (addProxy (host r) (port r) x)
-         req <- parseReq (T.unpack u) >>= addProxy'
-         let req' = req{requestHeaders = customHeaders ++ requestHeaders req}
-         resp <- newManager (mkManagerSettings  (TLSSettingsSimple disableCertificateValidation False False) Nothing) >>= httpLbs req'
-         return (B.concat $ toChunks $ responseBody resp,
-                 UTF8.toText `fmap` lookup hContentType (responseHeaders resp))
+  lookupEnv = IO.lookupEnv
+  getCurrentTime = IO.getCurrentTime
+  getCurrentTimeZone = IO.getCurrentTimeZone
+  newStdGen = IO.newStdGen
+  newUniqueHash = IO.newUniqueHash
 
-       case res of
-            Right r -> return r
-            Left e  -> throwError $ PandocHttpError u e
+  openURL = IO.openURL
+  readFileLazy = IO.readFileLazy
+  readFileStrict = IO.readFileStrict
 
-  readFileLazy s = liftIOError BL.readFile s
-  readFileStrict s = liftIOError B.readFile s
+  glob = IO.glob
+  fileExists = IO.fileExists
+  getDataFileName = IO.getDataFileName
+  getModificationTime = IO.getModificationTime
 
-  glob = liftIOError IO.glob
-  fileExists = liftIOError Directory.doesFileExist
-#ifdef EMBED_DATA_FILES
-  getDataFileName = return
-#else
-  getDataFileName = liftIOError Paths.getDataFileName
-#endif
-  getModificationTime = liftIOError IO.getModificationTime
   getCommonState = PandocIO $ lift get
-  putCommonState x = PandocIO $ lift $ put x
-  logOutput msg = liftIO $ do
-    UTF8.hPutStr stderr $
-        "[" ++ show (messageVerbosity msg) ++ "] "
-    alertIndent $ T.lines $ showLogMessage msg
+  putCommonState = PandocIO . lift . put
 
--- | Prints the list of lines to @stderr@, indenting every but the first
--- line by two spaces.
-alertIndent :: [Text] -> IO ()
-alertIndent [] = return ()
-alertIndent (l:ls) = do
-  UTF8.hPutStrLn stderr $ T.unpack l
-  mapM_ go ls
-  where go l' = do UTF8.hPutStr stderr "  "
-                   UTF8.hPutStrLn stderr $ T.unpack l'
+  logOutput = IO.logOutput
 
 -- | Extract media from the mediabag into a directory.
 extractMedia :: FilePath -> Pandoc -> PandocIO Pandoc
-extractMedia dir d = do
-  media <- getMediaBag
-  case [fp | (fp, _, _) <- mediaDirectory media] of
-        []  -> return d
-        fps -> do
-          mapM_ (writeMedia dir media) fps
-          return $ walk (adjustImagePath dir fps) d
-
--- | Write the contents of a media bag to a path.
-writeMedia :: FilePath -> MediaBag -> FilePath -> PandocIO ()
-writeMedia dir mediabag subpath = do
-  -- we join and split to convert a/b/c to a\b\c on Windows;
-  -- in zip containers all paths use /
-  let fullpath = dir </> unEscapeString (normalise subpath)
-  let mbcontents = lookupMedia subpath mediabag
-  case mbcontents of
-       Nothing -> throwError $ PandocResourceNotFound $ T.pack subpath
-       Just (_, bs) -> do
-         report $ Extracting $ T.pack fullpath
-         liftIOError (createDirectoryIfMissing True) (takeDirectory fullpath)
-         logIOError $ BL.writeFile fullpath bs
-
--- | If the given Inline element is an image with a @src@ path equal to
--- one in the list of @paths@, then prepends @dir@ to the image source;
--- returns the element unchanged otherwise.
-adjustImagePath :: FilePath -> [FilePath] -> Inline -> Inline
-adjustImagePath dir paths (Image attr lab (src, tit))
-   | T.unpack src `elem` paths = Image attr lab (T.pack dir <> "/" <> src, tit)
-adjustImagePath _ _ x = x
+extractMedia = IO.extractMedia