move BroadcastProvider from models.py to config.py

It's not something that is tied to a database table, and was causing
circular import issues

app/celery/broadcast_message_tasks.py

@@ -5,14 +5,14 @@ from notifications_utils.statsd_decorators import statsd
 
 from app import cbc_proxy_client, notify_celery
 from app.config import QueueNames
-from app.models import BroadcastEventMessageType, BroadcastProvider
+from app.models import BroadcastEventMessageType
 from app.dao.broadcast_message_dao import dao_get_broadcast_event_by_id
 
 
 @notify_celery.task(name="send-broadcast-event")
 @statsd(namespace="tasks")
 def send_broadcast_event(broadcast_event_id):
-    for provider in BroadcastProvider.PROVIDERS:
+    for provider in current_app.config['ENABLED_CBCS']:
         # TODO: Decide whether to send to each provider based on platform admin, service level settings, broadcast
         # level settings, etc.
         send_broadcast_provider_message.apply_async(

app/clients/cbc_proxy.py

@@ -2,7 +2,7 @@ import json
 
 import boto3
 
-from app.models import BroadcastProviders
+from app.config import BroadcastProvider
 
 # The variable names in this file have specific meaning in a CAP message
 #
@@ -70,7 +70,7 @@ class CBCProxyNoopClient:
 
 class CBCProxyClient:
     provider_function_name_map = {
-        BroadcastProviders.EE: 'bt-ee-1-proxy',
+        BroadcastProvider.EE: 'bt-ee-1-proxy',
     }
 
     def init_app(self, app):
@@ -111,7 +111,6 @@ class CBCProxyClient:
     def send_link_test(
         self,
         identifier,
-        provider,
     ):
         """
         link test - open up a connection to a specific provider, and send them an xml payload with a <msgType> of

app/config.py

@@ -56,6 +56,15 @@ class QueueNames(object):
         ]
 
 
+class BroadcastProvider:
+    EE = 'ee'
+    VODAFONE = 'vodafone'
+    THREE = 'three'
+    O2 = 'o2'
+
+    PROVIDERS = [EE, VODAFONE, THREE, O2]
+
+
 class TaskNames(object):
     PROCESS_INCOMPLETE_JOBS = 'process-incomplete-jobs'
     ZIP_AND_SEND_LETTER_PDFS = 'zip-and-send-letter-pdfs'
@@ -367,8 +376,7 @@ class Config(object):
     CBC_PROXY_AWS_ACCESS_KEY_ID = os.environ.get('CBC_PROXY_AWS_ACCESS_KEY_ID', '')
     CBC_PROXY_AWS_SECRET_ACCESS_KEY = os.environ.get('CBC_PROXY_AWS_SECRET_ACCESS_KEY', '')
 
-    # matches up with the strings in models.py::BroadcastProvider
-    ENABLED_CBCS = ['ee']
+    ENABLED_CBCS = {BroadcastProvider.EE}
 
 
 ######################