Notifications

config.example.py

@@ -15,6 +15,9 @@
 
 SPARKPOST_KEY = ""
 
+class FIREBASE:
+    CREDENTIALS = {} # Firebase serviceAccountKey.json
+    TOPIC = "announcements"
 
 class GOOGLE_CAL:
     CAL_ID = ""

config.travis.py

@@ -1,4 +1,5 @@
 import os
+import json
 from datetime import datetime, timezone, timedelta
 
 # uri should contain auth and default database
@@ -19,6 +20,9 @@
     'channel': os.getenv("TRAVIS_SLACK_CHANNEL_ID")
 }
 
+class FIREBASE:
+    CREDENTIALS = json.loads(os.getenv("FIREBASE_CREDENTIALS", "{}")) # Firebase serviceAccountKey.json
+    TOPIC = "announcements"
 
 class GOOGLE_CAL:
     CAL_ID = os.getenv("TRAVIS_GOOGLE_CAL_ID", "")

requirements.txt

@@ -5,18 +5,29 @@ bcrypt==3.1.5
 beautifulsoup4==4.6.3
 boto3==1.9.200
 botocore==1.12.253
+CacheControl==0.12.6
 cachetools==3.0.0
 certifi==2018.11.29
 cffi==1.11.5
 chardet==3.0.4
+colorama==0.4.4
 coverage==4.5.2
 dnspython==1.16.0
 docutils==0.15.2
+firebase-admin==4.4.0
+google-api-core==1.23.0
 google-api-python-client==1.7.6
 google-auth==1.6.2
 google-auth-httplib2==0.0.3
 google-auth-oauthlib==0.4.1
+google-cloud-core==1.4.3
+google-cloud-firestore==1.9.0
+google-cloud-storage==1.32.0
+google-crc32c==1.0.0
+google-resumable-media==1.1.0
+googleapis-common-protos==1.52.0
 googlemaps==3.0.2
+grpcio==1.33.2
 httplib2==0.12.0
 idna==2.8
 isort==4.3.4
@@ -26,9 +37,11 @@ lazy-object-proxy==1.3.1
 mccabe==0.6.1
 mock==4.0.2
 more-itertools==5.0.0
+msgpack==1.0.0
 oauth2client==4.1.3
 oauthlib==3.1.0
 pluggy==0.8.1
+protobuf==3.13.0
 py==1.7.0
 pyasn1==0.4.5
 pyasn1-modules==0.2.3
@@ -40,6 +53,7 @@ pytest==4.0.2
 pytest-cov==2.6.0
 pytest-ordering==0.6
 python-dateutil==2.7.5
+pytz==2020.4
 requests==2.21.0
 requests-oauthlib==1.3.0
 rsa==4.0

serverless.yml

@@ -255,3 +255,7 @@ functions:
       request:
         template:
           application/json: '$input.body'
+  notifications:
+    handler: src/notifications.update_notification_status
+    events:
+      - schedule: rate(10 minutes)

src/notifications.py

@@ -0,0 +1,114 @@
+import datetime
+import logging
+
+import firebase_admin
+from firebase_admin import credentials
+from firebase_admin import messaging
+
+from src import cal_announce
+from config import FIREBASE
+
+logger = logging.getLogger()
+logger.setLevel(logging.INFO)
+
+firebase_admin.initialize_app(credentials.Certificate(FIREBASE.CREDENTIALS))
+
+def send_notification(message_title, message_body, message_topic):
+    """Sends a notification to the appropriate topic in Firebase.
+
+    Sends a message consisting of a title and a body in the form of a push
+    notification to the Flutter mobile app.
+
+    Documentation:
+    https://pub.dev/packages/firebase_messaging
+    """
+    message = messaging.Message(
+        notification=messaging.Notification(
+            title=message_title,
+            body=message_body,
+        ),
+        topic=message_topic,
+        data={
+            "title": message_title,
+            "body": message_body,
+            "click_action": "FLUTTER_NOTIFICATION_CLICK"
+        }
+    )
+    return messaging.send(message)
+
+def check_slack(n=10):
+    """Retrieves latest message from slack. If the message timestamp is within n minutes of the
+    current time, returns the message body.
+    """
+    slack_resp = cal_announce.slack_announce({"num_messages": 1}, None)
+    if slack_resp["statusCode"] != 200:
+        return {"error": f'Error retriving slack messages: {slack_resp["statusCode"]} {slack_resp["body"]}'}
+
+    if not slack_resp["body"]:
+        return {"body": None}
+
+    latest_msg = slack_resp["body"][0]
+    msg_time = datetime.datetime.utcfromtimestamp(float(latest_msg["ts"]))
+    body = None
+    if msg_time + datetime.timedelta(minutes=n) > datetime.datetime.utcnow():
+        body = latest_msg["text"]
+    return {"body": body}
+
+def slack_notifications():
+    """Cron job to send Firebase notifications whenever a new Slack message appears in #announcements."""
+    slack_msg = check_slack()
+
+    if "error" in slack_msg:
+        logging.error(slack_msg["error"])
+        return
+
+    if not slack_msg["body"]:
+        logging.info("No new slack messages")
+        return
+
+    try:
+        response = send_notification("New Slack Announcement!", slack_msg["body"], FIREBASE.TOPIC)
+        logging.info(f'Firebase message for Slack ({slack_msg["body"]}) sent successfully! Response: {response}')
+    except Exception as e:
+        logging.error(f"Firebase messaging error: {e}")
+
+def check_google_calendar(n=10):
+    """Retrieves latest event from Google Calendar. If the event timestamp is within n minutes of the
+    current time, returns the event body.
+    """
+    cal_resp = cal_announce.google_cal({"num_events": 1}, None)
+    if cal_resp["statusCode"] != 200:
+        return {"error": f'Error retriving Google Calendar events: {cal_resp["statusCode"]} {cal_resp["body"]}'}
+
+    if not cal_resp["body"]:
+        return {"body": None}
+
+    latest_cal_event = cal_resp["body"][0]
+    event_time = datetime.datetime.strptime(latest_cal_event["start"]["dateTime"], "%Y-%m-%dT%H:%M:%S%z")
+    body = None
+    if datetime.datetime.now(event_time.tzinfo) + datetime.timedelta(minutes=n) > event_time:
+        body = latest_cal_event["summary"]
+    return {"body": body}
+
+def google_calendar_notifications():
+    """Cron job to send Firebase notifications whenever a new Google calendar event is approaching."""
+    google_cal_event = check_google_calendar()
+
+    if "error" in google_cal_event:
+        logging.error(google_cal_event["error"])
+        return
+
+    if not google_cal_event["body"]:
+        logging.info("No new Google Calendar events")
+        return
+
+    try:
+        response = send_notification("Calender Event Approaching!", google_cal_event["body"], FIREBASE.TOPIC)
+        logging.info(f'Firebase message for Google Calendar ({google_cal_event["body"]}) sent successfully! Response: {response}')
+    except Exception as e:
+        logging.error(f"Firebase messaging error: {e}")
+
+def update_notification_status():
+    """This function should be run as a cron job."""
+    slack_notifications()
+    google_calendar_notifications()

tests/test_notifications.py

@@ -0,0 +1,10 @@
+# This is different from regular lambda functions because it does not have a response to a user
+# In the event that this function fails, the only side effect is that Firebase notifications will not be made
+
+from src import notifications
+
+def test_notifications():
+    try:
+        notifications.update_notification_status()
+    except Exception as e:
+        print(f"Error: {e}")