new command: resetdanranking YYYY-MM-DD, sets every dan player to 1st dan with zero dan_points at the given date.

src/mahjong_ranking/management/commands/resetdanranking.py

@@ -0,0 +1,32 @@
+"""
+Rest all dan points to 0 at a given date.
+"""
+
+from django.core.management.base import BaseCommand
+from datetime import date, datetime, time
+from mahjong_ranking import models
+from django.utils.dateparse import parse_date
+from django.utils import timezone
+
+class Command(BaseCommand):
+    """ Recalculate all Kyu/Dan Rankings """
+
+    help = "reset every dan player to 1st dan with 0 points."
+
+    def add_arguments(self, parser):
+        parser.add_argument('reset_date', type=parse_date)
+
+    def handle(self, *args, **options):
+        reset_date = timezone.make_aware(datetime.combine(options.get('reset_date'), time(23, 59, 59)))
+        # models.KyuDanRanking.objects.update(until=reset_date, force_recalc=True)
+        dan_rankigns = models.KyuDanRanking.objects.filter(dan__isnull=False)
+        for ranking in dan_rankigns:
+            ranking.dan = 1
+            ranking.dan_points = 0
+            ranking.legacy_date = reset_date.date()
+            ranking.legacy_hanchan_count = ranking.hanchan_count
+            ranking.legacy_dan_points = ranking.dan_points
+            ranking.legacy_kyu_points = ranking.kyu_points
+            ranking.save()
+
+