module Handler.Utils.ExamOffice.Exam
  ( resultIsSynced
  ) where

import Import.NoFoundation

import qualified Database.Esqueleto as E

resultIsSynced :: E.SqlExpr (E.Value UserId) -- ^ office
               -> E.SqlExpr (Entity ExamResult)
               -> E.SqlExpr (E.Value Bool)
resultIsSynced authId examResult = (hasSchool E.&&. allSchools) E.||. anySync
  where
    anySync = E.exists . E.from $ \synced ->
      E.where_ $ synced E.^. ExamOfficeResultSyncedResult E.==. examResult E.^. ExamResultId
           E.&&. synced E.^. ExamOfficeResultSyncedTime   E.>=. examResult E.^. ExamResultLastChanged
    
    hasSchool = E.exists . E.from $ \userFunction ->
      E.where_ $ userFunction E.^. UserFunctionUser E.==. authId
           E.&&. userFunction E.^. UserFunctionFunction E.==. E.val SchoolExamOffice
    allSchools = E.not_ . E.exists . E.from $ \userFunction -> do
      E.where_ $ userFunction E.^. UserFunctionUser E.==. authId
           E.&&. userFunction E.^. UserFunctionFunction E.==. E.val SchoolExamOffice
      E.where_ . E.not_ . E.exists . E.from $ \synced ->
        E.where_ $ synced E.^. ExamOfficeResultSyncedSchool E.==. E.just (userFunction E.^. UserFunctionSchool)
             E.&&. synced E.^. ExamOfficeResultSyncedResult E.==. examResult E.^. ExamResultId
             E.&&. synced E.^. ExamOfficeResultSyncedTime   E.>=. examResult E.^. ExamResultLastChanged