From 91a7e11987e0b9ec6fe9b498f47db33c3c286d86 Mon Sep 17 00:00:00 2001
From: Wolfgang Witt <Wolfgang.Witt@campus.lmu.de>
Date: Tue, 6 Apr 2021 14:49:59 +0200
Subject: [PATCH] chore: implement favourite/blacklist toggle

---
 src/Handler/Course.hs | 65 +++++++++++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 18 deletions(-)

diff --git a/src/Handler/Course.hs b/src/Handler/Course.hs
index 78616947a..da9a491bd 100644
--- a/src/Handler/Course.hs
+++ b/src/Handler/Course.hs
@@ -7,7 +7,7 @@ module Handler.Course
 import Import
 
 import qualified Database.Esqueleto as E
-import qualified Database.Esqueleto.Utils as E
+import qualified Database.Persist as P
 
 import Handler.Course.Communication as Handler.Course
 import Handler.Course.Delete as Handler.Course
@@ -37,22 +37,51 @@ getCNotesR = postCNotesR
 postCNotesR _ _ _ = defaultLayout [whamlet|You have corrector access to this course.|]
 
 postCFavouriteR :: TermId -> SchoolId -> CourseShorthand -> Handler ()
-postCFavouriteR tid ssh csh = do
+postCFavouriteR tid ssh csh = void $ do
   muid <- maybeAuthPair
-  -- TODO swap FavouriteReason here
-  runDB $ do
-    -- Nothing means blacklist
-    -- should never return FavouriteCurrent
-    -- Just (Maybe reason, blacklist, associated)
-    currentReason <- storedFavouriteReason tid ssh csh muid
-    -- TODO change stored reason in DB
-    -- TODO participants can't remove favourite (only toggle between automatic/manual)?
-    pure ()
-
-  -- TODO participants can't remove favourite?
-  liftIO $ do
-    putStrLn "\nswapping FavouriteReason"
-    print (tid, ssh, csh)
+  runDB $ void $ do
+    mcid <- fmap (fmap E.unValue . listToMaybe) . E.select . E.from $ \course -> do
+      E.where_ $  course E.^. CourseTerm E.==. E.val tid
+            E.&&. course E.^. CourseSchool E.==. E.val ssh
+            E.&&. course E.^. CourseShorthand E.==. E.val csh
+      E.limit 1 -- we know that there is at most one match, but we tell the DB this info too
+      pure $ course E.^. CourseId
+    if | Just cid <- mcid, Just uid <- view _1 <$> muid -> do
+          now <- liftIO getCurrentTime
+          -- Nothing means blacklist
+          -- should never return FavouriteCurrent
+          (maybeReason, blacklist) <- storedFavouriteReason tid ssh csh muid >>= pure . \case
+            -- Maybe (Maybe reason, blacklist, associated)
+            Nothing                                       -> (Just FavouriteManual, False)
+          -- participants can't remove favourite (only toggle between automatic/manual)
+            Just (Just FavouriteManual, _blacklist, True) -> (Just FavouriteVisited, False)
+            Just (_reason, _blacklist, True)              -> (Just FavouriteManual, False)
+            Just (_reason, True, False)                   -> (Just FavouriteVisited, False)
+            Just (Just FavouriteManual, False, False)     -> (Nothing, True)
+            Just (_reason, False, False)                  -> (Just FavouriteManual, False)
+          -- change stored reason in DB
+          before <- storedFavouriteReason tid ssh csh muid
+          if blacklist
+            then do
+              E.deleteBy $ UniqueCourseFavourite uid cid
+              void $ E.upsertBy
+                (UniqueCourseNoFavourite uid cid)
+                (CourseNoFavourite uid cid)
+                []  -- entry shouldn't exists, but keep it unchanged anyway
+            else do
+              case maybeReason of
+                (Just reason) -> void $ E.upsertBy
+                  (UniqueCourseFavourite uid cid)
+                  (CourseFavourite uid cid reason now)
+                  [P.Update CourseFavouriteReason reason P.Assign]
+                  -- [CourseFavouriteReason E.=. E.val reason]
+                Nothing -> E.deleteBy $ UniqueCourseFavourite uid cid
+              E.deleteBy $ UniqueCourseNoFavourite uid cid
+          after <- storedFavouriteReason tid ssh csh muid
+          liftIO $ do
+            putStrLn $ "before: " <> pack (show before)
+            putStrLn $ "after: " <> pack (show after)
+            print (maybeReason, blacklist)
+       | otherwise -> pure ()
   -- show course page again
-  void $ redirect $ CourseR tid ssh csh CShowR
--- TODO Route for Icon to toggle manual Favorite
+  redirect $ CourseR tid ssh csh CShowR