{-# OPTIONS_GHC -Wwarn #-}

module Handler.Course
  ( module Handler.Course
  ) where

import Import

import qualified Database.Esqueleto as E
import qualified Database.Persist as P

import Handler.Course.Communication as Handler.Course
import Handler.Course.Delete as Handler.Course
import Handler.Course.Edit as Handler.Course
import Handler.Course.LecturerInvite as Handler.Course
import Handler.Course.List as Handler.Course
import Handler.Course.ParticipantInvite as Handler.Course
import Handler.Course.Register as Handler.Course
import Handler.Course.Show as Handler.Course
import Handler.Course.User as Handler.Course
import Handler.Course.Users as Handler.Course
import Handler.Course.Application as Handler.Course
import Handler.ExamOffice.Course as Handler.Course
import Handler.Course.News as Handler.Course
import Handler.Course.Events as Handler.Course
import Handler.Sheet.PersonalisedFiles as Handler.Course (getCPersonalFilesR)


getCHiWisR :: TermId -> SchoolId -> CourseShorthand -> Handler Html
getCHiWisR = error "CHiWisR: Not implemented"

getCNotesR, postCNotesR :: TermId -> SchoolId -> CourseShorthand -> Handler Html
-- NOTE: The route getNotesR is abused for correctorORlecturer access rights!
-- PROBLEM: Correctors usually don't know Participants by name (anonymous), maybe notes are not shared?
-- If they are shared, adjust MsgCourseUserNoteTooltip
getCNotesR = postCNotesR
postCNotesR _ _ _ = defaultLayout [whamlet|You have corrector access to this course.|]

postCFavouriteR :: TermId -> SchoolId -> CourseShorthand -> Handler ()
postCFavouriteR tid ssh csh = void $ do
  muid <- maybeAuthPair
  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
  redirect $ CourseR tid ssh csh CShowR