Merge pull request 'Fix and simplify rate calculation' (#15) from w2/photovoter_backend:rate-calculation-fix into main

Reviewed-on: https://git.iamonlyherefortheicecream.ml/DIWHY/photovoter_backend/pulls/15

main.py

@@ -166,15 +166,16 @@ async def photo_points():
     """Get points with the url of a photo and the rate"""
     # assume we always have at least some photos
     # fetch them all
+    # if frontend uses 1 and 0 to represent like and dislike
+    # we can just take the average and turn it into %
+    # 100 * AVG(marks.mark)
     cur.execute(
         """SELECT images.imgid, resizedpath, GPSLatitude, GPSLongitude, 
-                    100*SUM(marks.mark)/COUNT(marks.mark)/MAX(marks.mark)
+                    100 * AVG(marks.mark)
                 FROM images
                 LEFT JOIN marks ON images.imgid = marks.imgid
                 GROUP BY images.imgid;
-        """,  # 100 * SUM(marks.mark)/COUNT(marks.mark)/MAX(marks.mark)
-        # is an ad-hoc percentage of likes without know how front end defined like/dislike
-        # returns None with no marks (sqlite handles division by 0 gracefully)
+        """,
     )
     points = cur.fetchall()
     return [
@@ -183,7 +184,7 @@ async def photo_points():
             "url": point["resizedpath"],
             "lon": point["GPSLongitude"],
             "lat": point["GPSLatitude"],
-            "rate": point["100*SUM(marks.mark)/COUNT(marks.mark)/MAX(marks.mark)"],
+            "rate": point["100 * AVG(marks.mark)"],
         }
         for point in points
     ]