Send monthly reports on 1st of every month, not randomly during the month

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to this project will be documented in this file.
 - Add "last_duration" attribute to the Check API resource (#257)
 - Upgrade to psycopg2 2.8.3
 - Add Go usage example
+- Send monthly reports on 1st of every month, not randomly during the month
 
 ### Bug Fixes
 - Prevent double-clicking the submit button in signup form

hc/accounts/views.py

@@ -32,6 +32,7 @@ from hc.accounts.forms import (
 )
 from hc.accounts.models import Profile, Project, Member
 from hc.api.models import Channel, Check, TokenBucket
+from hc.lib.date import choose_next_report_date
 from hc.payments.models import Subscription
 
 NEXT_WHITELIST = (
@@ -355,7 +356,7 @@ def notifications(request):
             if profile.reports_allowed != form.cleaned_data["reports_allowed"]:
                 profile.reports_allowed = form.cleaned_data["reports_allowed"]
                 if profile.reports_allowed:
-                    profile.next_report_date = now() + td(days=30)
+                    profile.next_report_date = choose_next_report_date()
                 else:
                     profile.next_report_date = None
 

hc/api/management/commands/sendreports.py

@@ -6,6 +6,7 @@ from django.db.models import Q
 from django.utils import timezone
 from hc.accounts.models import NO_NAG, Profile
 from hc.api.models import Check
+from hc.lib.date import choose_next_report_date
 
 
 def num_pinged_checks(profile):
@@ -31,28 +32,29 @@ class Command(BaseCommand):
         )
 
     def handle_one_monthly_report(self):
-        now = timezone.now()
-        month_before = now - timedelta(days=30)
-        month_after = now + timedelta(days=30)
-
-        report_due = Q(next_report_date__lt=now)
+        report_due = Q(next_report_date__lt=timezone.now())
         report_not_scheduled = Q(next_report_date__isnull=True)
 
         q = Profile.objects.filter(report_due | report_not_scheduled)
         q = q.filter(reports_allowed=True)
-        q = q.filter(user__date_joined__lt=month_before)
         profile = q.first()
 
         if profile is None:
+            # No matching profiles found – nothing to do right now.
             return False
 
-        # A sort of optimistic lock. Try to update next_report_date,
+        # A sort of optimistic lock. Will try to update next_report_date,
         # and if does get modified, we're in drivers seat:
         qq = Profile.objects.filter(
             id=profile.id, next_report_date=profile.next_report_date
         )
 
-        num_updated = qq.update(next_report_date=month_after)
+        # Next report date is currently not scheduled: schedule it and move on.
+        if profile.next_report_date is None:
+            qq.update(next_report_date=choose_next_report_date())
+            return True
+
+        num_updated = qq.update(next_report_date=choose_next_report_date())
         if num_updated != 1:
             # next_report_date was already updated elsewhere, skipping
             return True

hc/api/tests/test_sendreports.py

@@ -8,20 +8,24 @@ from hc.test import BaseTestCase
 from mock import Mock
 
 
-class SendAlertsTestCase(BaseTestCase):
+class SendReportsTestCase(BaseTestCase):
     def setUp(self):
-        super(SendAlertsTestCase, self).setUp()
+        super(SendReportsTestCase, self).setUp()
 
-        # Make alice eligible for reports:
-        # account needs to be more than one month old
-        self.alice.date_joined = now() - td(days=365)
-        self.alice.save()
-
-        # Make alice eligible for nags:
+        # Make alice eligible for a monthly report:
+        self.profile.next_report_date = now() - td(hours=1)
+        # and for a nag
         self.profile.nag_period = td(hours=1)
         self.profile.next_nag_date = now() - td(seconds=10)
         self.profile.save()
 
+        # Disable bob's and charlie's monthly reports so they don't interfere
+        self.bobs_profile.reports_allowed = False
+        self.bobs_profile.save()
+
+        self.charlies_profile.reports_allowed = False
+        self.charlies_profile.save()
+
         # And it needs at least one check that has been pinged.
         self.check = Check(project=self.project, last_ping=now())
         self.check.status = "down"
@@ -37,6 +41,7 @@ class SendAlertsTestCase(BaseTestCase):
 
         self.profile.refresh_from_db()
         self.assertTrue(self.profile.next_report_date > now())
+        self.assertEqual(self.profile.next_report_date.day, 1)
         self.assertEqual(len(mail.outbox), 1)
 
         email = mail.outbox[0]
@@ -49,6 +54,18 @@ class SendAlertsTestCase(BaseTestCase):
         found = Command().handle_one_monthly_report()
         self.assertFalse(found)
 
+    def test_it_fills_blank_next_report_date(self):
+        self.profile.next_report_date = None
+        self.profile.save()
+
+        found = Command().handle_one_monthly_report()
+        self.assertTrue(found)
+
+        self.profile.refresh_from_db()
+        self.assertTrue(self.profile.next_report_date)
+        self.assertEqual(self.profile.next_report_date.day, 1)
+        self.assertEqual(len(mail.outbox), 0)
+
     def test_it_obeys_reports_allowed_flag(self):
         self.profile.reports_allowed = False
         self.profile.save()

hc/lib/date.py

@@ -1,4 +1,5 @@
 from datetime import datetime as dt
+from random import randint
 from django.utils import timezone
 
 
@@ -81,3 +82,22 @@ def month_boundaries(months=2):
             y = y - 1
 
     return result
+
+
+def choose_next_report_date(now=None):
+    """ Calculate the target date for the next monthly report.
+
+    Monthly reports should get sent on 1st of each month, at a random
+    time after 12PM UTC (so it's over the month boundary even in UTC-12).
+
+    """
+
+    if now is None:
+        now = timezone.now()
+
+    h, m, s = randint(12, 23), randint(0, 59), randint(0, 59)
+
+    if now.month == 12:
+        return now.replace(now.year + 1, 1, 1, h, m, s)
+    else:
+        return now.replace(now.year, now.month + 1, 1, h, m, s)

hc/lib/tests/test_date.py

@@ -1,7 +1,7 @@
-from datetime import timedelta as td
+from datetime import datetime as dt, timedelta as td
 from django.test import TestCase
 
-from hc.lib.date import format_hms
+from hc.lib.date import format_hms, choose_next_report_date
 
 
 class DateFormattingTestCase(TestCase):
@@ -24,3 +24,22 @@ class DateFormattingTestCase(TestCase):
 
         s = format_hms(td(seconds=60 * 60))
         self.assertEqual(s, "1 h 0 min 0 sec")
+
+
+class NextReportDateTestCase(TestCase):
+    def test_it_works(self):
+        # October
+        nao = dt(year=2019, month=10, day=15, hour=6)
+        result = choose_next_report_date(nao)
+        self.assertEqual(result.year, 2019)
+        self.assertEqual(result.month, 11)
+        self.assertEqual(result.day, 1)
+        self.assertTrue(result.hour >= 12)
+
+        # December
+        nao = dt(year=2019, month=12, day=15, hour=6)
+        result = choose_next_report_date(nao)
+        self.assertEqual(result.year, 2020)
+        self.assertEqual(result.month, 1)
+        self.assertEqual(result.day, 1)
+        self.assertTrue(result.hour >= 12)