From f4c92e9c650a0cab74dafb0fd81b2977419c09f3 Mon Sep 17 00:00:00 2001
From: Gabriel Augendre <gabriel@augendre.info>
Date: Mon, 1 Jun 2020 13:44:54 +0200
Subject: [PATCH] Improve perfs

---
 manuels/admin.py  | 16 +++++++++++++++
 manuels/models.py | 50 ++++++++++++++++++++++++++++++++++-------------
 2 files changed, 52 insertions(+), 14 deletions(-)

diff --git a/manuels/admin.py b/manuels/admin.py
index a339da7..c3051ce 100644
--- a/manuels/admin.py
+++ b/manuels/admin.py
@@ -1,4 +1,5 @@
 from django.contrib import admin, messages
+from django.db.models import Prefetch
 from import_export import resources, fields
 from import_export.admin import ExportMixin
 from import_export.widgets import IntegerWidget, DecimalWidget
@@ -69,24 +70,33 @@ class LevelAdmin(ExportMixin, admin.ModelAdmin):
     list_editable = ['order']
     list_display_links = ['name']
 
+    def get_queryset(self, request):
+        return super(LevelAdmin, self).get_queryset(request).prefetch_related(
+            Prefetch("book_set", to_attr="prefetched_books"))
+
     def non_acquired_book_count(self, obj: Level):
         return obj.non_acquired_book_count
+
     non_acquired_book_count.short_description = 'Nombre de livres à acheter (hors consommables)'
 
     def non_acquired_book_price(self, obj: Level):
         return f'{obj.non_acquired_book_price:.2f}€'
+
     non_acquired_book_price.short_description = 'Coût des livres à acheter (hors consommables)'
 
     def non_acquired_consumable_count(self, obj: Level):
         return obj.non_acquired_consumable_count
+
     non_acquired_consumable_count.short_description = 'Nombre de consommables à acheter'
 
     def non_acquired_consumable_price(self, obj: Level):
         return f'{obj.non_acquired_consumable_price:.2f}€'
+
     non_acquired_consumable_price.short_description = 'Coût des consommables à acheter'
 
     def non_acquired_total_price(self, obj: Level):
         return f'{obj.non_acquired_total_price:.2f}€'
+
     non_acquired_total_price.short_description = 'Coût total à acheter'
 
 
@@ -126,6 +136,9 @@ class BookAdmin(ExportMixin, admin.ModelAdmin):
     ]
     readonly_fields = ['created_at', 'updated_at']
 
+    def get_queryset(self, request):
+        return super(BookAdmin, self).get_queryset(request).select_related("editor", "level", "teacher")
+
     def update_with_decitre(self, request, queryset):
         for book in queryset:
             try:
@@ -171,3 +184,6 @@ class SuppliesRequirementAdmin(ExportMixin, admin.ModelAdmin):
     list_editable = ['done']
     readonly_fields = ['created_at', 'updated_at']
     list_filter = ['done', 'teacher', 'level']
+
+    def get_queryset(self, request):
+        return super(SuppliesRequirementAdmin, self).get_queryset(request).select_related("level", "teacher")
diff --git a/manuels/models.py b/manuels/models.py
index 7863d21..c12b5b2 100644
--- a/manuels/models.py
+++ b/manuels/models.py
@@ -127,34 +127,56 @@ class Level(BaseModel):
     def __str__(self):
         return self.name
 
+    @property
+    def non_acquired_consumables(self):
+        if hasattr(self, "prefetched_books"):
+            return filter(lambda book: book.consumable and not book.previously_acquired, self.prefetched_books)
+        return self.book_set.filter(consumable=True, previously_acquired=False)
+
     @property
     def non_acquired_consumable_count(self):
-        return self.book_set.filter(consumable=True, previously_acquired=False).count()
+        if hasattr(self, "prefetched_books"):
+            return len(list(self.non_acquired_consumables))
+        return self.non_acquired_consumables.count()
 
     @property
     def non_acquired_consumable_price(self):
-        price = self.book_set.filter(consumable=True, previously_acquired=False).aggregate(Sum('price')).get('price__sum', 0)
-        if price is None:
-            return 0
-        return price
+        if hasattr(self, "prefetched_books"):
+            return sum(map(lambda book: book.price, self.non_acquired_consumables))
+        return self.non_acquired_consumables.aggregate(Sum('price')).get(
+            'price__sum', 0)
+
+    @property
+    def non_acquired_books(self):
+        if hasattr(self, "prefetched_books"):
+            return filter(lambda book: not book.consumable and not book.previously_acquired, self.prefetched_books)
+        return self.book_set.filter(consumable=False, previously_acquired=False)
 
     @property
     def non_acquired_book_count(self):
-        return self.book_set.filter(consumable=False, previously_acquired=False).count()
+        if hasattr(self, "prefetched_books"):
+            return len(list(self.non_acquired_books))
+        return self.non_acquired_books.count()
 
     @property
     def non_acquired_book_price(self):
-        price = self.book_set.filter(consumable=False, previously_acquired=False).aggregate(Sum('price')).get('price__sum', 0)
-        if price is None:
-            return 0
-        return price
+        if hasattr(self, "prefetched_books"):
+            return sum(map(lambda book: book.price, self.non_acquired_books))
+        return self.non_acquired_books.aggregate(Sum('price')).get(
+            'price__sum', 0)
+
+    @property
+    def non_acquired_items(self):
+        if hasattr(self, "prefetched_books"):
+            return filter(lambda book: not book.previously_acquired, self.prefetched_books)
+        return self.book_set.filter(previously_acquired=False)
 
     @property
     def non_acquired_total_price(self):
-        price = self.book_set.filter(previously_acquired=False).aggregate(Sum('price')).get('price__sum', 0)
-        if price is None:
-            return 0
-        return price
+        if hasattr(self, "prefetched_books"):
+            return sum(map(lambda book: book.price, self.non_acquired_items))
+        return self.non_acquired_items.aggregate(Sum('price')).get(
+            'price__sum', 0)
 
 
 class Editor(BaseModel):