From 3d73df081d241fa2d67dc81e8aa1fdfb041051e0 Mon Sep 17 00:00:00 2001
From: alice <alice@packetimpact.net>
Date: Sat, 29 Aug 2020 20:12:57 +0200
Subject: [PATCH] add tasks to replace cron-scheduled scripts

---
 ccvpn/celery.py     |  8 ++++++
 lambdainst/tasks.py | 65 +++++++++++++++++++++++++++++++++++++++++++--
 payments/tasks.py   | 21 +++++++++++++--
 3 files changed, 90 insertions(+), 4 deletions(-)

diff --git a/ccvpn/celery.py b/ccvpn/celery.py
index 4f8a65b..eb7be6d 100644
--- a/ccvpn/celery.py
+++ b/ccvpn/celery.py
@@ -21,10 +21,18 @@ app.conf.beat_schedule = {
         'task': 'payments.tasks.check_subscriptions',
         'schedule': crontab(hour=1),
     },
+    'payments__cancel_old_payments': {
+        'task': 'payments.tasks.cancel_old_payments',
+        'schedule': crontab(hour=2),
+    },
     'lambdainst__resync': {
         'task': 'lambdainst.tasks.push_all_users',
         'schedule': crontab(day_of_week=1),
     },
+    'lambdainst__notify_account_expiration': {
+        'task': 'lambdainst.tasks.notify_account_expiration',
+        'schedule': crontab(hour='*/6'),
+    },
 }
 
 # Load task modules from all registered Django app configs.
diff --git a/lambdainst/tasks.py b/lambdainst/tasks.py
index 2d2585c..f775704 100644
--- a/lambdainst/tasks.py
+++ b/lambdainst/tasks.py
@@ -1,9 +1,23 @@
 import logging
+from datetime import timedelta
+from celery import task
+from django.db.models import Q, F
+from django.db import transaction
+from django.conf import settings
+from django.utils import timezone
+from django.template.loader import get_template
+from django.core.mail import send_mass_mail
+from constance import config as site_config
 import django_lcore
-from lambdainst.models import User
+
+from ccvpn.common import parse_integer_list
+from lambdainst.models import User, VPNUser
+
+ROOT_URL = settings.ROOT_URL
+SITE_NAME = settings.TICKETS_SITE_NAME
 
 logger = logging.getLogger(__name__)
-from celery import task
+
 
 @task(autoretry_for=(Exception,), default_retry_delay=60*60)
 def push_all_users():
@@ -16,6 +30,7 @@ def push_all_users():
 
         django_lcore.sync_user(u.vpnuser, fail_silently=False)
 
+
 @task(autoretry_for=(Exception,), max_retries=10, retry_backoff=True)
 def push_user(user_id):
     user = User.objects.get(id=user_id)
@@ -23,3 +38,49 @@ def push_user(user_id):
     django_lcore.sync_user(user.vpnuser, fail_silently=False)
 
 
+@task
+def notify_account_expiration():
+    """ Notify users near the end of their subscription """
+    from_email = settings.DEFAULT_FROM_EMAIL
+
+    for v in parse_integer_list(site_config.NOTIFY_DAYS_BEFORE):
+        emails = []
+        users = list(get_next_expirations(v))
+        logging.info("sending -%d day notification to %d users", v, len(users))
+
+        with transaction.atomic():
+            for u in users:
+                # Ignore users with active subscriptions
+                # They will get notified only if it gets cancelled (payments
+                # processors will cancel after a few failed payments)
+                if u.get_subscription():
+                    continue
+
+                ctx = dict(site_name=SITE_NAME, user=u.user,
+                            exp=u.expiration, url=ROOT_URL)
+                text = get_template('lambdainst/mail_expire_soon.txt').render(ctx)
+                emails.append(("CCrypto VPN Expiration", text, from_email, [u.user.email]))
+                logging.debug("sending -%d days notify to %s" % (v, u.user.email))
+
+                u.last_expiry_notice = timezone.now()
+                u.save()
+
+            send_mass_mail(emails)
+
+
+def get_next_expirations(days=3):
+    """ Gets users whose subscription will expire in some days """
+
+    limit_date = timezone.now() + timedelta(days=days)
+
+    users = VPNUser.objects.exclude(user__email__exact='')
+
+    users = users.filter(expiration__gt=timezone.now())  # Not expired
+    users = users.filter(expiration__lt=limit_date)  # Expire in a few days
+
+    # Make sure we dont send the notice twice
+    users = users.filter(Q(last_expiry_notice__isnull=True)
+                         | Q(expiration__gt=F('last_expiry_notice')
+                             + timedelta(days=days)))
+    return users
+
diff --git a/payments/tasks.py b/payments/tasks.py
index 0010c6e..2430f95 100644
--- a/payments/tasks.py
+++ b/payments/tasks.py
@@ -1,9 +1,12 @@
 import logging
+from datetime import timedelta
+from django.utils import timezone
+from celery import task
 
-from .models import Subscription, ACTIVE_BACKENDS
+from payments.models import Payment
+from .models import Payment, Subscription, ACTIVE_BACKENDS
 
 logger = logging.getLogger(__name__)
-from celery import task
 
 @task
 def check_subscriptions():
@@ -14,3 +17,17 @@ def check_subscriptions():
         sub.refresh_from_db()
         ACTIVE_BACKENDS['stripe'].refresh_subscription(sub)
         sub.save()
+
+@task
+def cancel_old_payments():
+    expdate = timezone.now() - timedelta(days=3)
+
+    expired = Payment.objects.filter(created__lte=expdate, status='new',
+                                     paid_amount=0)
+
+    logger.info("cancelling %d pending payments older than 3 days (%s)", len(expired), expdate.isoformat())
+
+    for p in expired:
+        logger.debug("cancelling payment #%d (%s): created on %s", p.id, p.user.username, p.created)
+        p.status = 'cancelled'
+        p.save()