Enable the listener only during some hours

1 files changed, 20 insertions, 6 deletions

diff --git a/src/executable/haskell/Service/AdListener.hs b/src/executable/haskell/Service/AdListener.hs
index c393f38..9af92f4 100644
--- a/src/executable/haskell/Service/AdListener.hs
+++ b/src/executable/haskell/Service/AdListener.hs
@@ -5,8 +5,8 @@ module Service.AdListener
 import           Control.Concurrent   (threadDelay)
 import qualified Data.Text            as T
 import qualified Data.Text.IO         as T
+import qualified Data.Time.LocalTime  as LocalTime
 import           Network.Wreq.Session (Session)
-import           Prelude              hiding (error)
 
 import           Conf                 (Conf)
 import qualified Conf
@@ -21,10 +21,11 @@ import qualified View.Ad              as Ad
 
 start :: Conf -> Session -> IO ()
 start conf session = do
-  ads <- fetchAds conf session
+  -- ads <- fetchAds conf session
+  let ads = []
   let newURLs = map Ad.url ads
   T.putStrLn "Listening to new ads…"
-  waitListenInterval conf
+  sleepUntilReady conf
   listenToNewAdsWithViewedURLs conf session newURLs
 
 listenToNewAdsWithViewedURLs :: Conf -> Session -> [URL] -> IO ()
@@ -39,7 +40,7 @@ listenToNewAdsWithViewedURLs conf session viewedURLs = do
         sendMail conf newAds
     else
       return ()
-  waitListenInterval conf
+  sleepUntilReady conf
   listenToNewAdsWithViewedURLs conf session (viewedURLs ++ newURLs)
 
 fetchAds :: Conf -> Session -> IO [Ad]
@@ -61,5 +62,18 @@ sendMail conf ads =
       mail = Mail (Conf.mailFrom conf) (Conf.mailTo conf) title plainBody
   in  MailService.send (Conf.mailMock conf) mail >> return ()
 
-waitListenInterval :: Conf -> IO ()
-waitListenInterval = threadDelay . (*) 1000000 . round . Conf.listenInterval
+sleepUntilReady :: Conf -> IO ()
+sleepUntilReady conf = do
+  timeSinceMidnight <-
+    (LocalTime.timeOfDayToTime . LocalTime.localTimeOfDay . LocalTime.zonedTimeToLocalTime)
+      <$> LocalTime.getZonedTime
+  case TimeUtils.asleepDuration (Conf.listenFrom conf) (Conf.listenTo conf) timeSinceMidnight of
+    Just d -> do
+      sleepSeconds d
+
+    Nothing ->
+      -- TODO 04/09/2019: Add noise
+      sleepSeconds . Conf.listenInterval $ conf
+  where
+    sleepSeconds =
+      threadDelay . (*) 1000000 . round