Simplifies query for earliest year

bookwyrm/views/annual_summary.py

@@ -3,7 +3,7 @@ from datetime import date
 from uuid import uuid4
 
 from django.contrib.auth.decorators import login_required
-from django.db.models import Case, When, Avg, Sum
+from django.db.models import Avg, Sum, Min, Case, When
 from django.http import Http404
 from django.shortcuts import redirect
 from django.template.response import TemplateResponse
@@ -185,7 +185,12 @@ def privacy_verification(request, user, year, year_key):
 def is_year_available(user, year):
     """return boolean"""
 
-    earliest_year = int(get_earliest_year(user, year))
+    earliest_year = user.readthrough_set.filter(finish_date__isnull=False).aggregate(
+        Min("finish_date")
+    )["finish_date__min"]
+    if not earliest_year:
+        return False
+    earliest_year = earliest_year.year
     today = date.today()
     year = int(year)
     if earliest_year <= year < today.year:
@@ -196,39 +201,6 @@ def is_year_available(user, year):
     return False
 
 
-def get_earliest_year(user, year):
-    """return the earliest finish_date or shelved_date year for user books in read shelf"""
-
-    read_shelfbooks = models.ShelfBook.objects.filter(user__id=user.id).filter(
-        shelf__identifier__exact="read"
-    )
-    read_shelfbooks_list = list(read_shelfbooks.values("book", "shelved_date"))
-
-    book_dates = []
-
-    for book in read_shelfbooks_list:
-        earliest_finished = (
-            models.ReadThrough.objects.filter(user__id=user.id)
-            .filter(book_id=book["book"])
-            .exclude(finish_date__exact=None)
-            .order_by("finish_date")
-            .values("finish_date")
-            .first()
-        )
-
-        if earliest_finished:
-            book_dates.append(
-                min(earliest_finished["finish_date"], book["shelved_date"])
-            )
-        else:
-            book_dates.append(book["shelved_date"])
-
-    if book_dates:
-        return min(book_dates).year
-
-    return year
-
-
 def get_books_from_shelfbooks(books_ids):
     """return an ordered QuerySet of books from a list"""