checking response to return 2xx

src/Main.hs

@@ -6,13 +6,13 @@ import System.Environment
 import Data.Time.Clock
 import Data.Time.Format
 import Data.Time.Clock.POSIX
-import Network.HTTP.Conduit (simpleHttp)
+import Network.HTTP.Conduit 
+import Network.HTTP.Simple (getResponseStatusCode, getResponseBody) 
 import Data.List.Split
 import Data.Algorithm.Diff
 import Data.Algorithm.DiffOutput
 import Data.ByteString.Lazy.UTF8 (toString) 
 import System.IO
-
 data GeneratorState = IsRunning | IsFinished
   deriving (Eq)
 
@@ -52,16 +52,25 @@ genOutput (Just changes) time timecodeFile= do
 genOutput Nothing _ _ = return()
 
 -- Returning fetched url as a string separated by \n
-fetchFile :: String -> IO [String]
+fetchFile :: String -> IO (Either String [String])
 fetchFile url = do
-    html <- simpleHttp url
-    return $ (splitOn ("\n")) . toString $ html
+    request <- parseRequest url
+    manager <- newManager tlsManagerSettings
+    response <- httpLbs request manager
+    let statusCode = getResponseStatusCode response
+    if statusCode `div` 100 == 2 then do
+      return $ Right ((splitOn ("\n")) . toString $ getResponseBody response)
+    else do
+      return $ Left (show statusCode)
+    
   
 -- Main Loop
 timecodeGenerator :: GeneratorState -> [String] -> UTCTime -> String -> String -> IO ()
 timecodeGenerator IsFinished _ _  _ _ = return ()
 timecodeGenerator IsRunning prevFile time url timecodeFile = do
-    newFile <- fetchFile url
+    fetched <- fetchFile url
+    case fetched of
+      Right newFile -> do
         currTime <- getCurrentTime
         let changes =  getChanges newFile prevFile
         let diffTime =  myFormatDiffTime (currTime, time)
@@ -74,6 +83,9 @@ timecodeGenerator IsRunning prevFile time url timecodeFile = do
           timecodeGenerator IsRunning newFile time url timecodeFile
         else
           timecodeGenerator IsFinished newFile time url timecodeFile
+      Left err -> do
+        print err
+        timecodeGenerator IsRunning prevFile time url timecodeFile
         
 -- Commandline arguments:
 -- 1. Link to markdown file
@@ -84,6 +96,10 @@ main = do
   let url:timecodeFile:xs = args
   time <- getCurrentTime
   file <- fetchFile url
+  case file of
+    Left e -> do
+      putStrLn $ (++) "Error: " $ show e 
+    Right file -> do
       appendToFile timecodeFile $ "New Timecodes starts here \n "
       appendToFile timecodeFile $ show time
       timecodeGenerator IsRunning file time url timecodeFile