create broadcast_provider_message and use id from that instead

(instead of using the id from broadcast_event)

we need every XML blob we send to have a different ID. if we're sending
different XML blobs for each provider, then each one should have a
different identifier. So, instead of taking the identifier from the
broadcast_event, take it from the broadcast_provider_message instead.

Note: We're still going to the broadcast_event for most fields, to
ensure they stay consistent between different providers. The last thing
we want is for different phone networks to get different content

tests/app/dao/test_broadcast_message_dao.py

@@ -1,11 +1,12 @@
 from datetime import datetime
-from app.models import BROADCAST_TYPE
-from app.models import BroadcastEventMessageType
-from app.dao.broadcast_message_dao import get_earlier_events_for_broadcast_event
+
+from freezegun import freeze_time
+
+from app.models import BROADCAST_TYPE, BroadcastStatusType, BroadcastEventMessageType
+from app.dao.broadcast_message_dao import get_earlier_events_for_broadcast_event, create_broadcast_provider_message
 
 from tests.app.db import create_broadcast_message, create_template, create_broadcast_event
 
-
 def test_get_earlier_events_for_broadcast_event(sample_service):
     t = create_template(sample_service, BROADCAST_TYPE)
     bm = create_broadcast_message(t)
@@ -41,3 +42,21 @@ def test_get_earlier_events_for_broadcast_event(sample_service):
     # only fetches earlier events, and they're in time order
     earlier_events = get_earlier_events_for_broadcast_event(events[2].id)
     assert earlier_events == [events[0], events[1]]
+
+
+@freeze_time('2020-02-03 04:05:06')
+def test_create_broadcast_provider_message_creates_in_correct_state(sample_broadcast_service):
+    t = create_template(sample_broadcast_service, BROADCAST_TYPE)
+    broadcast_message = create_broadcast_message(t, status=BroadcastStatusType.APPROVED)
+    broadcast_event = create_broadcast_event(
+        broadcast_message,
+        sent_at=datetime(2020, 1, 1, 12, 0, 0),
+        message_type=BroadcastEventMessageType.ALERT,
+        transmitted_content={'body': 'Initial content'}
+    )
+
+    broadcast_provider_message = create_broadcast_provider_message(broadcast_event, 'fake-provider')
+
+    assert broadcast_provider_message.status == 'sending'
+    assert broadcast_provider_message.broadcast_event_id == broadcast_event.id
+    assert broadcast_provider_message.created_at == datetime.utcnow()