Add prerequisites handling to CaseCollection and implement user access checks

atlas/views.py

@@ -105,6 +105,7 @@ from .models import (
     SeriesImage,
     UncategorisedDicom,
     UserReportAnswer,
+    PrerequisiteRequired
 )
 from .tables import (
     CaseCollectionTable,
@@ -2192,11 +2193,21 @@ def collection_take_start(request, pk, cid=None, passcode=None):
     collection = get_object_or_404(CaseCollection, pk=pk)
     print(f"Collection: {collection}")
 
-    try:  
+    try:
         collection.check_user_can_take(cid, passcode, request.user)
         valid_user = True
     except Http404:
         valid_user = False
+    except PrerequisiteRequired as e:
+        # Show a friendly page linking to the required collection rather than 404
+        prereq = getattr(e, 'prereq', None)
+        return render(
+            request,
+            'atlas/prerequisite_required.html',
+            {'message': str(e), 'prereq': prereq},
+        )
+
+
     #valid_user = collection.check_logged_in_user(request)
 
 
@@ -2611,7 +2622,11 @@ def collection_take_overview(
     """
     collection = get_object_or_404(CaseCollection, pk=pk)
 
-    collection.check_user_can_take(cid, passcode, request.user)
+    try:
+        collection.check_user_can_take(cid, passcode, request.user)
+    except PrerequisiteRequired as e:
+        prereq = getattr(e, 'prereq', None)
+        return render(request, 'atlas/prerequisite_required.html', {'message': str(e), 'prereq': prereq})
 
     cid_user_exam = collection.get_or_create_cid_user_exam(
         cid=cid, user_user=request.user
@@ -2684,7 +2699,11 @@ def collection_case_view_take_answers(
     """ """
     collection = get_object_or_404(CaseCollection, pk=pk)
 
-    collection.check_user_can_take(cid, passcode, request.user)
+    try:
+        collection.check_user_can_take(cid, passcode, request.user)
+    except PrerequisiteRequired as e:
+        prereq = getattr(e, 'prereq', None)
+        return render(request, 'atlas/prerequisite_required.html', {'message': str(e), 'prereq': prereq})
 
     case, case_count = collection.get_case_by_index(case_number, case_count=True)
 
@@ -2733,7 +2752,11 @@ def collection_case_view_take(
     form = None
     answer: None | CidReportAnswer | UserReportAnswer = None
 
-    collection.check_user_can_take(cid, passcode, request.user)
+    try:
+        collection.check_user_can_take(cid, passcode, request.user)
+    except PrerequisiteRequired as e:
+        prereq = getattr(e, 'prereq', None)
+        return render(request, 'atlas/prerequisite_required.html', {'message': str(e), 'prereq': prereq})
 
     case, case_count = collection.get_case_by_index(case_number, case_count=True)
 
@@ -2818,6 +2841,18 @@ def collection_case_view_take(
                         # If this was a timed-out submission, mark as completed
                         if request.POST.get('timed_out') == '1':
                             answer.completed = True
+                            ## Also mark the overall exam as completed for this user/CID
+                            #try:
+                            #    cid_user_exam.completed = True
+                            #    cid_user_exam.save()
+                            #    # Record an exam status entry
+                            #    collection.exam_user_status.create(
+                            #        cid_user_exam=cid_user_exam,
+                            #        status="submitted",
+                            #        extra="autosubmit",
+                            #    )
+                            #except Exception:
+                            #    logger.exception("Failed to mark cid_user_exam completed on autosubmit")
 
                         answer.save()