module Handler.Utils.Database
  ( getSchoolsOf
  , makeSchoolDictionaryDB, makeSchoolDictionary
  ) where

import Import

import Data.Map as Map
-- import Data.CaseInsensitive (CI)
-- import qualified Data.CaseInsensitive as CI


import qualified Database.Esqueleto as E

makeSchoolDictionaryDB :: DB (Map.Map SchoolId SchoolName)
makeSchoolDictionaryDB = makeSchoolDictionary <$> selectList [] [Asc SchoolShorthand]

makeSchoolDictionary :: [Entity School] -> Map.Map SchoolId SchoolName
makeSchoolDictionary schools = Map.fromDistinctAscList [ (ssh,schoolName) | Entity ssh School{schoolName} <- schools ]

-- getSchoolsOf :: ( BaseBackend backend ~ SqlBackend
--                 , PersistEntityBackend val ~ SqlBackend
--                 , PersistUniqueRead backend, PersistQueryRead backend
--                 , IsPersistBackend backend, PersistEntity val, MonadIO m) =>
--   UserId -> EntityField val SchoolId -> EntityField val UserId -> ReaderT backend m [E.Value SchoolName]
getSchoolsOf :: (PersistEntity val, PersistEntityBackend val ~ SqlBackend) => UserId -> EntityField val SchoolId -> EntityField val UserId -> DB [SchoolName]
getSchoolsOf uid uschool uuser = fmap (Import.map E.unValue) $ E.select $ E.from $ \(urights `E.InnerJoin` school) -> do
  E.on     $ urights E.^. uschool E.==. school E.^. SchoolId
  E.where_ $ urights E.^. uuser   E.==. E.val uid
  E.orderBy [E.asc $ school E.^.SchoolName]
  return $ school E.^. SchoolName