From e11e12307afb87dd0931f86e85e607305c8e4cf8 Mon Sep 17 00:00:00 2001
From: Adam Goldsmith <adam@adamgoldsmith.name>
Date: Wed, 7 Aug 2024 13:01:28 -0400
Subject: [PATCH] Improve various admin pages performance using select/prefetch
 related

---
 membershipworks/admin.py |  6 ++++--
 paperwork/admin.py       |  1 +
 rentals/admin.py         | 22 ++++++++++++++++------
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/membershipworks/admin.py b/membershipworks/admin.py
index f6fed07..70c3a2b 100644
--- a/membershipworks/admin.py
+++ b/membershipworks/admin.py
@@ -96,6 +96,7 @@ class FlagAdmin(BaseMembershipWorksAdmin):
 @admin.register(Transaction)
 class TransactionAdmin(BaseMembershipWorksAdmin):
     list_display = ["timestamp", "member", "name", "type", "sum", "note"]
+    list_select_related = ["member"]
     list_filter = ["type"]
     show_facets = admin.ShowFacets.ALWAYS
     search_fields = ["member", "name", "type", "note"]
@@ -115,6 +116,7 @@ class EventMeetingTimeInline(admin.TabularInline):
 class EventInstructorAdmin(admin.ModelAdmin):
     autocomplete_fields = ["member"]
     search_fields = ["name", "member__account_name"]
+    list_select_related = ["member"]
 
 
 @admin.register(EventInvoice)
@@ -130,6 +132,7 @@ class EventInvoiceAdmin(admin.ModelAdmin):
         "date_paid",
         "amount",
     ]
+    list_select_related = ["event__instructor__member"]
     list_filter = [
         ("date_paid", admin.EmptyFieldListFilter),
     ]
@@ -186,8 +189,7 @@ class EventAdmin(DjangoObjectActions, admin.ModelAdmin):
     change_actions = ["fetch_details"]
     actions = ["fetch_details"]
 
-    @property
-    def readonly_fields(self):
+    def get_readonly_fields(self, request: HttpRequest, obj: EventExt) -> list[str]:
         fields = []
         for field in Event._meta.get_fields():
             if field.auto_created or field.many_to_many or not field.concrete:
diff --git a/paperwork/admin.py b/paperwork/admin.py
index 5e8a324..d71354b 100644
--- a/paperwork/admin.py
+++ b/paperwork/admin.py
@@ -57,6 +57,7 @@ class DepartmentAdmin(admin.ModelAdmin):
         "shop_lead_flag",
         "list_reply_to_address",
     ]
+    list_select_related = ["shop_lead_flag", "parent"]
 
 
 class CertificationVersionInline(admin.TabularInline):
diff --git a/rentals/admin.py b/rentals/admin.py
index a3ae7d6..d98bb58 100644
--- a/rentals/admin.py
+++ b/rentals/admin.py
@@ -1,6 +1,7 @@
 from django import forms
 from django.contrib import admin
-from django.db.models import Prefetch
+from django.db.models import Prefetch, QuerySet
+from django.http import HttpRequest
 
 from membershipworks.models import Member
 
@@ -22,11 +23,17 @@ class LockerBankAdmin(admin.ModelAdmin):
     inlines = [LockerUnitInline]
     prepopulated_fields = {"slug": ("name",)}
 
+    def get_queryset(self, request: HttpRequest) -> QuerySet[LockerBank]:
+        return super().get_queryset(request).prefetch_related("units")
+
 
 @admin.register(LockerUnit)
 class LockerUnitAdmin(admin.ModelAdmin):
     inlines = [LockerInfoInline]
 
+    def get_queryset(self, request: HttpRequest) -> QuerySet[LockerUnit]:
+        return super().get_queryset(request).prefetch_related("bank")
+
 
 @admin.register(LockerInfo)
 class LockerInfoAdmin(admin.ModelAdmin):
@@ -43,11 +50,14 @@ class LockerInfoAdmin(admin.ModelAdmin):
     ]
     list_display_links = ["locker_unit", "address"]
 
-    def get_queryset(self, request):
-        return LockerInfo.objects.select_related(
-            "locker_unit", "locker_unit__bank"
-        ).prefetch_related(
-            Prefetch("renter", queryset=Member.objects.only("account_name"))
+    def get_queryset(self, request: HttpRequest) -> QuerySet[LockerInfo]:
+        return (
+            super()
+            .get_queryset(request)
+            .select_related("locker_unit", "locker_unit__bank")
+            .prefetch_related(
+                Prefetch("renter", queryset=Member.objects.only("account_name"))
+            )
         )
 
     def get_changelist_formset(self, request, **kwargs):