From 84e8b02594f5455d80c9c901d449d19dfd570a68 Mon Sep 17 00:00:00 2001
From: Yohann D'ANELLO <yohann.danello@gmail.com>
Date: Tue, 28 Jul 2020 15:25:08 +0200
Subject: [PATCH] :bug: Calculating permissions faster

---
 apps/activity/views.py      |  3 +++
 apps/member/views.py        |  2 +-
 apps/permission/backends.py | 50 +++++++++++++------------------------
 3 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/apps/activity/views.py b/apps/activity/views.py
index df3f00ea..7bc8def5 100644
--- a/apps/activity/views.py
+++ b/apps/activity/views.py
@@ -38,6 +38,9 @@ class ActivityListView(ProtectQuerysetMixin, LoginRequiredMixin, SingleTableView
     table_class = ActivityTable
     ordering = ('-date_start',)
 
+    def get_queryset(self):
+        return super().get_queryset().distinct()
+
     def get_context_data(self, **kwargs):
         context = super().get_context_data(**kwargs)
 
diff --git a/apps/member/views.py b/apps/member/views.py
index 614c5bc1..9d6b34e5 100644
--- a/apps/member/views.py
+++ b/apps/member/views.py
@@ -642,7 +642,7 @@ class ClubManageRolesView(ProtectQuerysetMixin, LoginRequiredMixin, UpdateView):
         del form.fields['bank']
 
         club = self.object.club
-        form.fields['roles'].queryset = Role.objects.filter(Q(weirole__isnull=isinstance(club, WEIClub))
+        form.fields['roles'].queryset = Role.objects.filter(Q(weirole__isnull=not isinstance(club, WEIClub))
                                                             & (Q(for_club__isnull=True) | Q(for_club=club))).all()
 
         return form
diff --git a/apps/permission/backends.py b/apps/permission/backends.py
index 99f1b2da..374e67e6 100644
--- a/apps/permission/backends.py
+++ b/apps/permission/backends.py
@@ -36,27 +36,20 @@ class PermissionBackend(ModelBackend):
             # Unauthenticated users have no permissions
             return Permission.objects.none()
 
-        qs = Permission.objects.annotate(
-            club=F("role__membership__club"),
-            membership=F("role__membership"),
-        ).filter(
-            (
-                Q(
-                    role__membership__date_start__lte=timezone.now().today(),
-                    role__membership__date_end__gte=timezone.now().today(),
-                )
-                | Q(permanent=True)
-            )
-            & Q(role__membership__user=user)
-            & Q(type=t)
-            & Q(mask__rank__lte=get_current_session().get("permission_mask", 0))
-        )
+        memberships = Membership.objects.filter(user=user).all()
+        
+        perms = []
+
+        for membership in memberships:
+            for role in membership.roles.all():
+                for perm in role.permissions.filter(type=t, mask__rank__lte=get_current_session().get("permission_mask", 42)).all():
+                    if not perm.permanent:
+                        if membership.date_start > timezone.now().date() or membership.date_end < timezone.now().date():
+                            continue
+                    perm.membership = membership
+                    perms.append(perm)
+        return perms
 
-        if settings.DATABASES[qs.db]["ENGINE"] == 'django.db.backends.postgresql_psycopg2':
-            qs = qs.distinct('pk', 'club')
-        else:  # SQLite doesn't support distinct fields.
-            qs = qs.distinct()
-        return qs
 
     @staticmethod
     def permissions(user, model, type):
@@ -67,22 +60,13 @@ class PermissionBackend(ModelBackend):
         :param type: The type of the permissions: view, change, add or delete
         :return: A generator of the requested permissions
         """
-        clubs = {}
-        memberships = {}
 
         for permission in PermissionBackend.get_raw_permissions(user, type):
-            if not isinstance(model.model_class()(), permission.model.model_class()) or not permission.club:
+            if not isinstance(model.model_class()(), permission.model.model_class()) or not permission.membership:
                 continue
 
-            if permission.club not in clubs:
-                clubs[permission.club] = club = Club.objects.get(pk=permission.club)
-            else:
-                club = clubs[permission.club]
-
-            if permission.membership not in memberships:
-                memberships[permission.membership] = membership = Membership.objects.get(pk=permission.membership)
-            else:
-                membership = memberships[permission.membership]
+            membership = permission.membership
+            club = membership.club
 
             permission = permission.about(
                 user=user,
@@ -113,7 +97,6 @@ class PermissionBackend(ModelBackend):
         :param field: The field of the model to test, if concerned
         :return: A query that corresponds to the filter to give to a queryset
         """
-
         if user is None or isinstance(user, AnonymousUser):
             # Anonymous users can't do anything
             return Q(pk=-1)
@@ -163,6 +146,7 @@ class PermissionBackend(ModelBackend):
         perm = perm.split('.')[-1].split('_', 2)
         perm_type = perm[0]
         perm_field = perm[2] if len(perm) == 3 else None
+
         ct = ContentType.objects.get_for_model(obj)
         if any(permission.applies(obj, perm_type, perm_field)
                for permission in PermissionBackend.permissions(user_obj, ct, perm_type)):