From 23fdf4af6d56298b06ca0d062aab995695a76294 Mon Sep 17 00:00:00 2001
From: Gregor Kleen <gregor.kleen@ifi.lmu.de>
Date: Thu, 4 Feb 2021 11:07:25 +0100
Subject: [PATCH] refactor: switch exams list to cached study features only

---
 src/Handler/Utils/ExamOffice/Exam.hs |  2 +-
 src/Handler/Utils/StudyFeatures.hs   | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/Handler/Utils/ExamOffice/Exam.hs b/src/Handler/Utils/ExamOffice/Exam.hs
index e9f903471..586d9b7cb 100644
--- a/src/Handler/Utils/ExamOffice/Exam.hs
+++ b/src/Handler/Utils/ExamOffice/Exam.hs
@@ -42,7 +42,7 @@ examOfficeExamResultAuth authId examResult = authByUser E.||. authByField E.||.
       E.on $ studyFeatures E.^. StudyFeaturesField E.==. examOfficeField E.^. ExamOfficeFieldField
       E.where_ . E.maybe E.false id . E.subSelectMaybe . E.from $ \course -> do
         E.where_ $ course E.^. CourseId E.==. cId
-        return . E.just $ isCourseStudyFeature course studyFeatures
+        return . E.just $ isCourseStudyFeatureCached course studyFeatures
       E.where_ $ studyFeatures E.^. StudyFeaturesUser E.==. examResult E.^. ExamResultUser
            E.&&. examOfficeField E.^. ExamOfficeFieldOffice E.==. authId
            E.&&. examOfficeField E.^. ExamOfficeFieldField E.==. studyFeatures E.^. StudyFeaturesField
diff --git a/src/Handler/Utils/StudyFeatures.hs b/src/Handler/Utils/StudyFeatures.hs
index 7e3dc481a..252121b17 100644
--- a/src/Handler/Utils/StudyFeatures.hs
+++ b/src/Handler/Utils/StudyFeatures.hs
@@ -4,9 +4,9 @@ module Handler.Utils.StudyFeatures
   , _userTableField, _userTableDegree, _userTableSemester, _userTableFieldType
   , UserTableStudyFeatures(..)
   , _UserTableStudyFeatures
-  , isRelevantStudyFeature, isRelevantStudyFeatureCached
+  , isRelevantStudyFeature, isRelevantStudyFeatureCached, isRelevantStudyFeatureCached'
   , cacheStudyFeatureRelevance
-  , isCourseStudyFeature, courseUserStudyFeatures
+  , isCourseStudyFeature, isCourseStudyFeatureCached, courseUserStudyFeatures
   , isExternalExamStudyFeature, externalExamUserStudyFeatures
   , isTermStudyFeature
   , isAllocationStudyFeature, allocationUserStudyFeatures
@@ -121,12 +121,19 @@ isRelevantStudyFeatureCached :: PersistEntity record
 isRelevantStudyFeatureCached termField record studyFeatures
   = E.bool calcNow useCache $ studyFeatures E.^. StudyFeaturesRelevanceCached
   where
-    useCache
-      = E.exists . E.from $ \relevantStudyFeatures ->
-          E.where_ $ relevantStudyFeatures E.^. RelevantStudyFeaturesTerm E.==. record E.^. termField
-               E.&&. relevantStudyFeatures E.^. RelevantStudyFeaturesStudyFeatures E.==. studyFeatures E.^. StudyFeaturesId
+    useCache = isRelevantStudyFeatureCached' termField record studyFeatures
     calcNow = isRelevantStudyFeature termField record studyFeatures
 
+isRelevantStudyFeatureCached' :: PersistEntity record
+                              => EntityField record TermId
+                              -> E.SqlExpr (Entity record)
+                              -> E.SqlExpr (Entity StudyFeatures)
+                              -> E.SqlExpr (E.Value Bool)
+isRelevantStudyFeatureCached' termField record studyFeatures
+  = E.exists . E.from $ \relevantStudyFeatures ->
+      E.where_ $ relevantStudyFeatures E.^. RelevantStudyFeaturesTerm E.==. record E.^. termField
+           E.&&. relevantStudyFeatures E.^. RelevantStudyFeaturesStudyFeatures E.==. studyFeatures E.^. StudyFeaturesId
+
 cacheStudyFeatureRelevance :: MonadIO m
                            => (E.SqlExpr (Entity StudyFeatures) -> E.SqlExpr (E.Value Bool))
                            -> SqlPersistT m ()
@@ -146,6 +153,9 @@ cacheStudyFeatureRelevance fFilter = do
 isCourseStudyFeature :: E.SqlExpr (Entity Course) -> E.SqlExpr (Entity StudyFeatures) -> E.SqlExpr (E.Value Bool)
 isCourseStudyFeature = isRelevantStudyFeatureCached CourseTerm
 
+isCourseStudyFeatureCached :: E.SqlExpr (Entity Course) -> E.SqlExpr (Entity StudyFeatures) -> E.SqlExpr (E.Value Bool)
+isCourseStudyFeatureCached = isRelevantStudyFeatureCached' CourseTerm
+
 courseUserStudyFeatures :: MonadIO m => CourseId -> UserId -> SqlPersistT m UserTableStudyFeatures
 courseUserStudyFeatures cId uid = do
   feats <- E.select . E.from $ \(course `E.InnerJoin` studyFeatures `E.InnerJoin` terms `E.InnerJoin` degree) -> do