From caf354c7e5bcb5142d8b4358824d22d3de122f34 Mon Sep 17 00:00:00 2001
From: Yuchen Pei <hi@ypei.me>
Date: Fri, 27 May 2022 18:57:24 +1000
Subject: break apart the code, timestamp read imp.

---
 src/F2Md/Import.hs | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 src/F2Md/Import.hs

(limited to 'src/F2Md/Import.hs')

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 = '-'
+
-- 
cgit v1.2.3