Add a bell curve graph and total points calculation (#1325)

* Add a bell curve graph and total points calculation to admin panel statistics
* Closes #608

CTFd/api/v1/statistics/__init__.py

@@ -8,3 +8,4 @@ from CTFd.api.v1.statistics import challenges  # noqa: F401
 from CTFd.api.v1.statistics import submissions  # noqa: F401
 from CTFd.api.v1.statistics import teams  # noqa: F401
 from CTFd.api.v1.statistics import users  # noqa: F401
+from CTFd.api.v1.statistics import scores  # noqa: F401

CTFd/api/v1/statistics/scores.py

@@ -0,0 +1,43 @@
+from collections import defaultdict
+
+from flask_restx import Resource
+
+from CTFd.api.v1.statistics import statistics_namespace
+from CTFd.models import db, Challenges
+from CTFd.utils.decorators import admins_only
+from CTFd.utils.scores import get_standings
+
+
+@statistics_namespace.route("/scores/distribution")
+class ScoresDistribution(Resource):
+    @admins_only
+    def get(self):
+        challenge_count = Challenges.query.count() or 1
+        total_points = (
+            Challenges.query.with_entities(db.func.sum(Challenges.value).label("sum"))
+            .filter_by(state="visible")
+            .first()
+            .sum
+        ) or 0
+        # Convert Decimal() to int in some database backends for Python 2
+        total_points = int(total_points)
+
+        # Divide score by challenges to get brackets with explicit floor division
+        bracket_size = total_points // challenge_count
+
+        # Get standings
+        standings = get_standings(admin=True)
+
+        # Iterate over standings and increment the count for each bracket for each standing within that bracket
+        bottom, top = 0, bracket_size
+        count = 1
+        brackets = defaultdict(lambda: 0)
+        for t in reversed(standings):
+            if ((t.score >= bottom) and (t.score <= top)) or t.score <= 0:
+                brackets[top] += 1
+            else:
+                count += 1
+                bottom, top = (bracket_size, (bracket_size * count))
+                brackets[top] += 1
+
+        return {"success": True, "data": {"brackets": brackets}}