module Handler.Utils.ExamOffice.Course
  ( courseExamOfficeSchools
  ) where

import Import.NoFoundation

import qualified Database.Esqueleto as E
import qualified Database.Esqueleto.Utils as E


courseExamOfficeSchools :: E.SqlExpr (E.Value UserId)
                        -> E.SqlExpr (E.Value CourseId)
                        -> E.SqlQuery (E.SqlExpr (Entity School), E.SqlExpr (E.Value Bool)) -- ^ @Entity School@ and @forced@
courseExamOfficeSchools user _course = E.from $ \(school `E.InnerJoin` userFunction `E.InnerJoin` (examOfficeField `E.FullOuterJoin` examOfficeUser))
  -> E.distinctOnOrderBy [E.asc $ userFunction E.^. UserFunctionSchool] $ do
       E.on   E.false
       E.on $ (      examOfficeUser E.?. ExamOfficeUserUser E.==. E.just user
               E.&&. examOfficeUser E.?. ExamOfficeUserOffice E.==. E.just (userFunction E.^. UserFunctionUser)
              )
        E.||. (      examOfficeField E.?. ExamOfficeFieldOffice E.==. E.just (userFunction E.^. UserFunctionUser)
               E.&&. E.exists ( E.from $ \studyFeatures ->
                                  E.where_ $ E.just (studyFeatures E.^. StudyFeaturesField) E.==. examOfficeField E.?. ExamOfficeFieldField
                                       E.&&. studyFeatures E.^. StudyFeaturesUser E.==. user
                              )
              )
       E.on $ school E.^. SchoolId E.==. userFunction E.^. UserFunctionSchool
        E.&&. userFunction E.^. UserFunctionFunction E.==. E.val SchoolExamOffice

       let forced = E.maybe E.true id $ examOfficeField E.?. ExamOfficeFieldForced 

       E.orderBy [E.desc forced]
       return $ (school, forced)