From d69022455983a5b3f8575bc226e5a9c3cc0f3c73 Mon Sep 17 00:00:00 2001
From: Mouse Reeve <mousereeve@riseup.net>
Date: Thu, 6 Jan 2022 09:39:51 -0800
Subject: [PATCH] Use weighted averages

---
 bookwyrm/templates/about/about.html |  6 +++---
 bookwyrm/views/landing/landing.py   | 17 ++++++++++++-----
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/bookwyrm/templates/about/about.html b/bookwyrm/templates/about/about.html
index 3dd53d19b..5aa68d1e0 100644
--- a/bookwyrm/templates/about/about.html
+++ b/bookwyrm/templates/about/about.html
@@ -30,7 +30,7 @@
                 </div>
                 <div class="media-content">
                     {% blocktrans trimmed with title=top_rated|book_title site_name=site.name rating=top_rated.rating|floatformat:1 %}
-                    <em>{{ title }}</em> is {{ site_name }}'s most beloved book, with a {{ rating }} rating out of 5
+                    <em>{{ title }}</em> is {{ site_name }}'s most beloved book, with an average rating of {{ rating }} out of 5.
                     {% endblocktrans %}
                 </div>
             </div>
@@ -44,7 +44,7 @@
                 </div>
                 <div class="media-content">
                     {% blocktrans trimmed with title=wanted|book_title site_name=site.name %}
-                    More {{ site_name }} users want to read <em>{{ title }}</em>
+                    More {{ site_name }} users want to read <em>{{ title }}</em>.
                     {% endblocktrans %}
                 </div>
             </div>
@@ -58,7 +58,7 @@
                 </div>
                 <div class="media-content">
                     {% blocktrans trimmed with title=controversial|book_title site_name=site.name %}
-                    <em>{{ title }}</em> has the most divisive ratings of any book on {{ site_name }}
+                    <em>{{ title }}</em> has the most divisive ratings of any book on {{ site_name }}.
                     {% endblocktrans %}
                 </div>
             </div>
diff --git a/bookwyrm/views/landing/landing.py b/bookwyrm/views/landing/landing.py
index 782cae24c..995d923ec 100644
--- a/bookwyrm/views/landing/landing.py
+++ b/bookwyrm/views/landing/landing.py
@@ -1,6 +1,6 @@
 """ non-interactive pages """
 from dateutil.relativedelta import relativedelta
-from django.db.models import Avg, StdDev, Count, Q
+from django.db.models import Avg, StdDev, Count, F, Q
 from django.template.response import TemplateResponse
 from django.utils import timezone
 from django.views import View
@@ -29,13 +29,20 @@ def about(request):
 
     books = models.Edition.objects.exclude(cover__exact="")
 
+    total_ratings = models.Review.objects.filter(user__local=True).count()
     data["top_rated"] = books.annotate(
-        rating=Avg("review__rating", filter=Q(review__user__local=True))
-    ).filter(rating__gt=0).order_by("-rating").first()
+        rating=Avg("review__rating", filter=Q(review__user__local=True)),
+        rating_count=Count("review__rating", filter=Q(review__user__local=True)),
+    ).annotate(
+        weighted=F("rating") * F("rating_count") / total_ratings
+    ).filter(weighted__gt=0).order_by("-weighted").first()
 
     data["controversial"] = books.annotate(
-        deviation=StdDev("review__rating")
-    ).filter(deviation__gt=0).order_by("-deviation").first()
+        deviation=StdDev("review__rating", filter=Q(review__user__local=True)),
+        rating_count=Count("review__rating", filter=Q(review__user__local=True)),
+    ).annotate(
+        weighted=F("deviation") * F("rating_count") / total_ratings
+    ).filter(weighted__gt=0).order_by("-weighted").first()
 
     data["wanted"] = books.annotate(
         shelf_count=Count("shelves", filter=Q(shelves__identifier="to-read"))