Support Whatsapp (WIP)

app/airq/controllers/api.py

@@ -23,23 +23,36 @@ def _get_supported_locale(locale: str) -> str:
 def sms_reply(locale: str) -> str:
     supported_locale = _get_supported_locale(locale)
     g.locale = supported_locale
+
     zipcode = request.values.get("Body", "").strip()
+
     phone_number = request.values.get("From", "").strip()
+    if phone_number.startswith("whatsapp:"):
+        phone_number = phone_number.lstrip("whatsapp:")
+        identifier_type = ClientIdentifierType.WHATSAPP
+    else:
+        identifier_type = ClientIdentifierType.PHONE_NUMBER
+
     response = commands.handle_command(
-        zipcode, phone_number, ClientIdentifierType.PHONE_NUMBER, supported_locale
+        zipcode, phone_number, identifier_type, supported_locale
     )
+
     return response.serialize()
 
 
 def test_command(locale: str) -> str:
     supported_locale = _get_supported_locale(locale)
     g.locale = supported_locale
+
     command = request.args.get("command", "").strip()
+
     if request.headers.getlist("X-Forwarded-For"):
         ip = request.headers.getlist("X-Forwarded-For")[0]
     else:
         ip = request.remote_addr
+
     response = commands.handle_command(
         command, ip, ClientIdentifierType.IP, supported_locale
     )
+
     return response.as_html()

app/airq/lib/twilio.py

@@ -2,11 +2,12 @@
 import logging
 import typing
 
-from airq import config
-
 from twilio.base.exceptions import TwilioRestException
 from twilio.rest import Client
 
+from airq import config
+from airq.models.clients import ClientIdentifierType
+
 
 logger = logging.getLogger(__name__)
 
@@ -15,6 +16,9 @@ class TwilioErrorCode(enum.IntEnum):
     OUT_OF_REGION = 21408
     UNSUBSCRIBED = 21610
 
+    # See https://www.twilio.com/docs/whatsapp/tutorial/send-whatsapp-notification-messages-templates#encountering-error-code-63016
+    NO_CONVERSATION = 63016
+
     @classmethod
     def from_exc(cls, exc: TwilioRestException) -> typing.Optional["TwilioErrorCode"]:
         for m in cls:
@@ -23,14 +27,21 @@ def from_exc(cls, exc: TwilioRestException) -> typing.Optional["TwilioErrorCode"
         return None
 
 
-def send_sms(
-    body: str, to_number: str, locale: str, media: typing.Optional[str] = None
+def send_message(
+    body: str,
+    to_number: str,
+    type_code: ClientIdentifierType,
+    locale: str,
+    media: typing.Optional[str] = None,
 ):
     from_number = config.TWILIO_NUMBERS.get(locale)
     if not from_number:
         logger.exception("Couldn't find a Twilio number for %s", locale)
         return
 
+    if type_code == ClientIdentifierType.WHATSAPP:
+        from_number = "whatsapp:" + from_number
+
     kwargs = dict(body=body, to=to_number, from_=from_number)
     if media:
         kwargs["media_url"] = media

app/airq/models/clients.py

@@ -21,8 +21,6 @@
 from airq.lib.readings import Pm25
 from airq.lib.readings import Readings
 from airq.lib.sms import coerce_phone_number
-from airq.lib.twilio import send_sms
-from airq.lib.twilio import TwilioErrorCode
 from airq.models.events import Event
 from airq.models.events import EventType
 from airq.models.zipcodes import Zipcode
@@ -34,6 +32,11 @@
 class ClientIdentifierType(enum.Enum):
     PHONE_NUMBER = 1
     IP = 2
+    WHATSAPP = 3
+
+    @property
+    def can_receive_messages(self) -> bool:
+        return self != self.IP
 
 
 class ClientQuery(BaseQuery):
@@ -69,7 +72,7 @@ def get_by_phone_number(self, phone_number: str) -> typing.Optional["Client"]:
     #
 
     def filter_phones(self) -> "ClientQuery":
-        return self.filter(Client.type_code == ClientIdentifierType.PHONE_NUMBER)
+        return self.filter(Client.type_code != ClientIdentifierType.IP)
 
     def filter_inactive_since(self, timestamp: float) -> "ClientQuery":
         return self.filter(Client.last_activity_at < timestamp).filter(
@@ -202,6 +205,10 @@ def __repr__(self) -> str:
     # and therefore shouldn't include it in its state
     EVENT_RESPONSE_TIME = datetime.timedelta(hours=1)
 
+    @property
+    def identifier_type(self) -> ClientIdentifierType:
+        return ClientIdentifierType(self.type_code)
+
     @classmethod
     def get_share_window(self) -> typing.Tuple[int, int]:
         ts = timestamp()
@@ -346,12 +353,28 @@ def is_in_send_window(self) -> bool:
         return send_start <= dt.hour < send_end
 
     def send_message(self, message: str, media: typing.Optional[str] = None) -> bool:
-        if self.type_code == ClientIdentifierType.PHONE_NUMBER:
+        from airq.lib.twilio import send_message
+        from airq.lib.twilio import TwilioErrorCode
+
+        if self.identifier_type.can_receive_messages:
             try:
-                send_sms(message, self.identifier, self.locale, media=media)
+                send_message(
+                    message,
+                    self.identifier,
+                    self.identifier_type,
+                    self.locale,
+                    media=media,
+                )
             except TwilioRestException as e:
                 code = TwilioErrorCode.from_exc(e)
-                if code:
+                if code == TwilioErrorCode.NO_CONVERSATION:
+                    logger.exception(
+                        'Sent non-template message "%s" to %s outside of a conversation',
+                        message,
+                        self,
+                    )
+                    return False
+                elif code:
                     logger.warning(
                         "Disabling alerts for recipient %s: %s",
                         self,
@@ -362,7 +385,6 @@ def send_message(self, message: str, media: typing.Optional[str] = None) -> bool
                 else:
                     raise
         else:
-            # Other clients types don't yet support message sending.
             logger.info("Not messaging client %s: %s", self.id, message)
 
         return True
@@ -406,6 +428,8 @@ def maybe_notify(self) -> bool:
         if was_alerted_recently and abs(curr_aqi - last_aqi) < 50:
             return False
 
+        # Warning! This is a template message used by Whatsapp. If you change it, make sure to add the new copy
+        # in the Twilio console or we won't be able to send it to Whatsapp users.
         message = gettext(
             'Air quality in %(city)s %(zipcode)s has changed to %(curr_aqi_level)s (AQI %(curr_aqi)s).\n\nReply "M" for Menu or "E" to end alerts.',
             city=self.zipcode.city.name,

app/migrations/versions/a3c90e054d3a_support_whatsapp_as_enum_member.py

@@ -0,0 +1,67 @@
+"""support whatsapp as enum member
+
+Revision ID: a3c90e054d3a
+Revises: 3dad84c99218
+Create Date: 2021-08-24 05:28:52.434323
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# Cribbed from https://markrailton.com/blog/creating-migrations-when-changing-an-enum-in-python-using-sql-alchemy
+
+# revision identifiers, used by Alembic.
+revision = "a3c90e054d3a"
+down_revision = "3dad84c99218"
+branch_labels = None
+depends_on = None
+
+# Enum 'type' for PostgreSQL
+enum_name = "clientidentifiertype"
+# Set temporary enum 'type' for PostgreSQL
+tmp_enum_name = "tmp_" + enum_name
+
+# Options for Enum
+old_options = ("PHONE_NUMBER", "IP")
+new_options = sorted(old_options + ("WHATSAPP",))
+
+# Create enum fields
+old_type = sa.Enum(*old_options, name=enum_name)
+new_type = sa.Enum(*new_options, name=enum_name)
+
+
+def upgrade():
+    # Rename current enum type to tmp_
+    op.execute("ALTER TYPE " + enum_name + " RENAME TO " + tmp_enum_name)
+    # Create new enum type in db
+    new_type.create(op.get_bind())
+    # Update column to use new enum type
+    op.execute(
+        "ALTER TABLE clients ALTER COLUMN type_code TYPE "
+        + enum_name
+        + " USING type_code::text::"
+        + enum_name
+    )
+    # Drop old enum type
+    op.execute("DROP TYPE " + tmp_enum_name)
+
+
+def downgrade():
+    # Instantiate db query
+    op.execute(
+        "DELETE FROM events WHERE client_id IN (SELECT id FROM clients WHERE type_code = 'WHATSAPP')"
+    )
+    op.execute("DELETE FROM clients WHERE type_code = 'WHATSAPP'")
+    # Rename enum type to tmp_
+    op.execute("ALTER TYPE " + enum_name + " RENAME TO " + tmp_enum_name)
+    # Create enum type using old values
+    old_type.create(op.get_bind())
+    # Set enum type as type for event_type column
+    op.execute(
+        "ALTER TABLE clients ALTER COLUMN type_code TYPE "
+        + enum_name
+        + " USING type_code::text::"
+        + enum_name
+    )
+    # Drop temp enum type
+    op.execute("DROP TYPE " + tmp_enum_name)

app/tests/test_clients.py

@@ -222,7 +222,7 @@ def test_send_message_raises_known_error_code(self):
         self.assertTrue(client.is_enabled_for_alerts)
         self.assertEqual(0, Event.query.count())
         with mock.patch(
-            "airq.models.clients.send_sms",
+            "airq.lib.twilio.send_message",
             side_effect=TwilioRestException(
                 "", "", code=TwilioErrorCode.OUT_OF_REGION.value
             ),
@@ -239,7 +239,7 @@ def test_send_message_raises_unknown_error_code(self):
         self.assertTrue(client.is_enabled_for_alerts)
         self.assertEqual(0, Event.query.count())
         with mock.patch(
-            "airq.models.clients.send_sms",
+            "airq.lib.twilio.send_message",
             side_effect=TwilioRestException("", "", code=77),
         ):
             with self.assertRaises(Exception):