Send license expiration notification emails

.env.example

@@ -0,0 +1,7 @@
+# For local dev, copy this file as '.env' and paste the mandrill api key as the password
+EMAIL_HOST_PASSWORD = 'super-secret'
+EMAIL_HOST = 'smtp.mandrillapp.com'
+EMAIL_PORT = 587
+EMAIL_HOST_USER = '[email protected]'
+
+BASE_URL = 'localhost:8000'

docker-compose.yml

@@ -24,6 +24,8 @@ services:
       # Docker automatically recognizes your changes.
       - .:/app
       - ${PWD}/docsearch/local_settings.dev.py:/app/docsearch/local_settings.py
+    env_file:
+      - .env
     command: python manage.py runserver 0.0.0.0:8000
 
   migration:

docsearch/admin.py

@@ -4,3 +4,7 @@
 
 admin.site.site_header = 'Forest Preserve of Cook County Document Search Admin'
 admin.site.site_title = 'Document Search'
+
+class NotificationSubscriptionAdmin(admin.ModelAdmin):
+  list_display = ["user"]
+admin.site.register(models.NotificationSubscription, NotificationSubscriptionAdmin)

docsearch/local_settings.example.py

@@ -1,4 +1,5 @@
 # See https://docs.djangoproject.com/en/3.0/howto/deployment/checklist/
+import os
 import socket
 
 # SECURITY WARNING: keep the secret key used in production secret!
@@ -52,3 +53,17 @@
         'ADMIN_URL': 'http://solr:8983/solr/admin/cores'
     },
 }
+
+BASE_URL = os.getenv('BASE_URL', 'localhost:8000')
+
+try:
+    EMAIL_HOST_PASSWORD = os.environ['EMAIL_HOST_PASSWORD']
+except KeyError:
+    print('Email password not found, email sending not turned on.')
+else:
+    EMAIL_HOST = os.getenv('EMAIL_HOST', 'smtp.mandrillapp.com')
+    EMAIL_PORT = os.getenv('EMAIL_PORT', 587)
+    EMAIL_HOST_USER = os.getenv('EMAIL_HOST_USER', '[email protected]')
+    EMAIL_USE_TLS = True
+
+    DEFAULT_FROM_EMAIL = EMAIL_HOST_USER

docsearch/management/commands/send_expiration_email.py

@@ -0,0 +1,119 @@
+from docsearch.models import License, NotificationSubscription
+from docsearch.settings import BASE_URL
+from django.core.management.base import BaseCommand
+from django.core.mail import EmailMessage
+from django.template.loader import render_to_string
+from django.db import transaction
+
+import datetime
+from dateutil.relativedelta import relativedelta
+from csv import DictWriter
+from io import StringIO
+
+
+class Command(BaseCommand):
+    help = (
+        "Send notification emails for nearly expired licenses."
+    )
+
+    def generate_csv(self, licenses):
+        '''
+        Create a file in memory with details of licenses, intended to be written later
+        '''
+        file = StringIO()
+        field_names = ["license_number", "end_date", "url"]
+        header = ["License Number", "End Date", "Link"]
+        writer = DictWriter(file, fieldnames=field_names)
+
+        writer.writer.writerow(header)
+        for l in licenses:
+            writer.writerow(l)
+
+        return file
+
+    def attach_csv(self, email, near_expired, date):
+        '''
+        If any expiring licenses exist, attach a csv report to the email
+        '''
+        if len(near_expired) > 0:
+            attachment = self.generate_csv(near_expired)
+            email.attach('expiring_licenses_{}.csv'.format(str(date.year)), attachment.getvalue())
+
+    def get_near_expired_licenses(self, present, future_limit):
+        '''
+        Returns all licenses expiring between now and a future date
+        '''
+        dates_to_exclude = ['continuous', 'indefinite', 'perpetual', 'cancelled', 'TBD']
+        licenses = License.objects.exclude(end_date=None).exclude(end_date__in=dates_to_exclude)
+
+        result = []
+        for l in licenses:
+            # The format is YYYY-MM-DD
+            year, month, day = [int(time) for time in l.end_date.split("-")]
+
+            end_date = datetime.date(year, month, day)
+            if present <= end_date and end_date <= future_limit:
+                obj = {
+                    "url": BASE_URL + l.get_absolute_url(),
+                    "license_number": l.license_number,
+                    "end_date": end_date
+                }
+
+                result.append(obj)
+
+        return result
+
+    def prep_email(self, subscribers, near_expired, date_range_start, date_range_end, subject):
+        '''
+        Assign recipients and build the contents of the email
+        '''
+        recipients = []
+        for sub in subscribers:
+            recipients.append(sub.user.email)
+            sub.notification_date = date_range_end
+            sub.save()
+
+        body = render_to_string(
+            'emails/license_expiration.html',
+            {
+                "n_licenses": str(len(near_expired)),
+                "date_range_start": date_range_start.strftime("%m/%d/%Y"),
+                "date_range_end": date_range_end.strftime("%m/%d/%Y"),
+            },
+        )
+
+        email = EmailMessage(
+            subject=subject,
+            body=body,
+            to=recipients,
+        )
+        email.content_subtype = 'html'
+
+        self.attach_csv(email, near_expired, date_range_start)
+
+        return email
+
+    @transaction.atomic
+    def handle(self, *args, **options):
+        today = datetime.date.today()
+
+        if NotificationSubscription.objects.filter(notification_date=today).exists():
+            self.stdout.write("Checking for licenses expiring soon...")
+
+            one_year_from_now = datetime.date.today() + relativedelta(years=1)
+            near_expired = self.get_near_expired_licenses(today, one_year_from_now)
+            self.stdout.write(f"{len(near_expired)} license(s) found")
+
+            subscribers = NotificationSubscription.objects.filter(notification_date=today)
+            subject = "Licenses expiring in the next 12 months"
+            email = self.prep_email(
+                subscribers=subscribers,
+                near_expired=near_expired,
+                date_range_start=today,
+                date_range_end=one_year_from_now,
+                subject=subject
+            )
+
+            self.stdout.write("Sending emails...")
+            email.send()
+            self.stdout.write(self.style.SUCCESS("Emails sent!"))