5 files changed, 216 insertions, 0 deletions
diff --git a/src/F2Md/Config.hs b/src/F2Md/Config.hs
new file mode 100644
index 0000000..ccb1871
--- /dev/null
+++ b/src/F2Md/Config.hs
@@ -0,0 +1,41 @@
+{-# LANGUAGE DeriveGeneric #-}
+
+module F2Md.Config (getUserdata, FeedUserdata(..)) where
+
+import F2Md.Utils
+import Data.Maybe
+import Data.Text (Text)
+import Data.Time
+import GHC.Generics
+import qualified Data.HashMap.Strict as HM
+import Data.Aeson
+import qualified Data.ByteString.Lazy as BSL
+
+data Config = Config
+  { dbPath :: String
+  , maildir :: String
+  , feeds :: [Text]
+  } deriving (Generic, Show)
+
+instance FromJSON Config
+
+data FeedUserdata = FeedUserdata
+  { url :: Text
+  , lastUpdated :: Maybe ZonedTime } deriving (Generic, Show)
+
+getUserdata :: FilePath -> IO ([FeedUserdata], Maybe FilePath)
+getUserdata file = do
+  config <- decode <$> BSL.readFile file
+  case config of
+    Nothing -> return ([], Nothing)
+    Just config' -> do
+      feedData <- getUserdata' config'
+      maildir' <- expandPath $ maildir config'
+      return (feedData, Just maildir')
+
+getUserdata' :: Config -> IO [FeedUserdata]
+getUserdata' (Config dbPath _ feeds) = do
+  decoded <- decode <$> (BSL.readFile =<< expandPath dbPath)
+  let decoded' = fromMaybe (HM.fromList []) decoded
+  return $
+    map (\url -> FeedUserdata url $ HM.lookup url decoded') feeds
diff --git a/src/F2Md/Export.hs b/src/F2Md/Export.hs
new file mode 100644
index 0000000..284ab22
--- /dev/null
+++ b/src/F2Md/Export.hs
@@ -0,0 +1,40 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module F2Md.Export (writeMessage) where
+
+import F2Md.Types
+import Data.Text (Text)
+import qualified Data.Text as T
+import System.Posix.Process
+import System.Posix.Files
+import Data.Time
+import Network.HostName
+import System.Random
+import System.FilePath
+
+
+formatMessage :: Message -> Text
+formatMessage (Message from subject date messageId body) =
+  "MIME-Version: 1.0\n" <> "Date: " <> date <> "\nSubject: " <> subject <>
+  "\nFrom: " <> from <> "\nMessage-ID: " <> messageId <>
+  "\nContent-Type: text/html" <> "\n\n" <> body
+
+genFilename :: FilePath -> IO String
+genFilename root = do
+  epoch <- formatTime defaultTimeLocale "%s" <$> getCurrentTime
+  pid <- getProcessID
+  host <- getHostName
+  rand <- randomRIO (10000, 99999) :: IO Int
+  return $ root </> "new" </> epoch <> "." <> show pid <> "." <>
+    host <> "." <> show rand
+
+genUniqFilename :: FilePath -> IO String
+genUniqFilename root = do
+  filename <- genFilename root
+  exists <- fileExist filename
+  if exists then genUniqFilename root else return filename
+
+writeMessage :: FilePath -> Message -> IO ()
+writeMessage root msg =
+  genUniqFilename root >>=
+  \filename -> writeFile filename $ T.unpack (formatMessage msg)
diff --git a/src/F2Md/Import.hs b/src/F2Md/Import.hs
new file mode 100644
index 0000000..ee68578
--- /dev/null
+++ b/src/F2Md/Import.hs
@@ -0,0 +1,102 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module F2Md.Import (toMessagesFromFile, toMessagesFromUrl) where
+
+import Control.Monad
+import Data.Time
+import System.Process
+import Data.UUID
+import Data.UUID.V4
+import Data.Char
+import Data.Text (Text)
+import Text.Feed.Types
+import qualified Data.Text as T
+import Data.Maybe
+import Text.Feed.Query
+import Data.Generics
+import Text.RSS.Syntax hiding (RSSItem)
+import Data.XML.Types
+import Text.Feed.Import
+import Text.Feed.Types
+import F2Md.Types
+
+toMessagesFromFile :: FilePath -> IO [Message]
+toMessagesFromFile file = do
+  feed <- parseFeedFromFile file
+  case feed of
+    Nothing -> return []
+    Just feed' ->
+      mapM (\msg -> toMessage (toFeedMetadata feed') msg) (getFeedItems feed')
+
+toMessagesFromUrl :: Text -> Maybe ZonedTime -> IO [Message]
+toMessagesFromUrl url after = do
+  feed <- parseFeedString <$> (fetchFeed $ T.unpack url)
+  case feed of
+    Nothing -> return []
+    Just feed' -> catMaybes <$>
+      mapM (\msg -> toMessage' after (toFeedMetadata feed') msg) (getFeedItems feed')
+
+wgetCommand :: String
+wgetCommand = "wget -O- 2>/dev/null"
+
+fetchFeed :: String -> IO String
+fetchFeed url = readCreateProcess (shell $ wgetCommand ++ " " ++ url) ""
+
+toMessage' :: Maybe ZonedTime -> FeedMetadata -> Item -> IO (Maybe Message)
+toMessage' after feed item
+  | isNothing after = toMessage feed item >>= return . Just
+  | isNothing date || zonedTimeToUTC (fromJust after) >= fromJust date =
+      return Nothing
+  | otherwise = toMessage feed item >>= return . Just
+  where date = join $ getItemPublishDate item
+
+toMessage :: FeedMetadata -> Item -> IO Message
+toMessage (FeedMetadata title author home) item = do
+  messageId <- genMessageId (fromMaybe "" home) (snd <$> getItemId item)
+  return $ Message
+    (fromMaybe title $ orElse (getItemAuthor' item) author)
+    (fromMaybe "Untitled" $ getItemTitle item)
+    (fromMaybe "" $ getItemDate item) -- default should be current date
+    messageId
+    (formatBody (getItemLink item) $
+     (getItemContent item) `orElse` (getItemContent' item) `orElse`
+     (getItemDescription item))
+--    title
+
+getItemAuthor' :: Item -> Maybe Text
+getItemAuthor' item = case getItemAuthor item of
+  Just "" -> Nothing
+  Just author -> Just author
+  Nothing -> Nothing
+
+getItemContent' :: Item -> Maybe Text
+getItemContent' (RSSItem item) =
+  (fmap (T.concat . elementText) . listToMaybe .
+   filter (\e -> namePrefix (elementName e) == Just "content"))
+  $ rssItemOther item
+getItemContent' _ = Nothing
+
+formatBody :: Maybe Text -> Maybe Text -> Text
+formatBody link desc =
+  let linkText = case link of
+        Nothing -> ""
+        Just link' -> "Link: " <> link' <> "\n\n" in
+    linkText <> (fromMaybe "" desc)
+
+toFeedMetadata :: Feed -> FeedMetadata
+toFeedMetadata feed =
+  FeedMetadata (getFeedTitle feed) (getFeedAuthor feed) (getFeedHome feed)
+
+genMessageId :: Text -> Maybe Text -> IO Text
+genMessageId feedLink guid = do
+  id <- case guid of
+          Just guid' -> return $ T.map hyphenateNonAlNum guid'
+          Nothing -> toText <$> nextRandom
+  return $
+    "<" <> id <> "@" <> (T.map hyphenateNonAlNum feedLink) <> ".gnu" <> ">"
+
+hyphenateNonAlNum :: Char -> Char
+hyphenateNonAlNum c
+  | isAlphaNum c = c
+  | otherwise = '-'
+
diff --git a/src/F2Md/Types.hs b/src/F2Md/Types.hs
new file mode 100644
index 0000000..cd579ce
--- /dev/null
+++ b/src/F2Md/Types.hs
@@ -0,0 +1,21 @@
+module F2Md.Types where
+
+import Data.Text (Text)
+import Data.Time
+
+data FeedMetadata = FeedMetadata
+  { title :: Text,
+    author :: Maybe Text,
+    home :: Maybe Text
+  }
+  deriving (Show)
+
+data Message = Message
+  { from :: Text,
+    subject :: Text,
+    date :: Text,
+    messageId :: Text,
+    body :: Text
+--    newsGroup :: Text
+  }
+  deriving (Show)
diff --git a/src/F2Md/Utils.hs b/src/F2Md/Utils.hs
new file mode 100644
index 0000000..149730e
--- /dev/null
+++ b/src/F2Md/Utils.hs
@@ -0,0 +1,12 @@
+module F2Md.Utils (expandPath) where
+
+import System.Directory
+import System.Posix.User
+
+expandPath :: FilePath -> IO FilePath
+expandPath path =
+  let (pre, post) = break (=='/') path in
+    case pre of
+      "~" -> (++ post) <$> getHomeDirectory
+      '~' : user -> (++ post) <$> homeDirectory <$> getUserEntryForName user
+      _ -> return path