Add API client for notification statistic

Adds a client for the endpoints added in
67c4bd2263

app/__init__.py

@@ -19,6 +19,7 @@ from app.notify_client.job_api_client import JobApiClient
 from app.notify_client.notification_api_client import NotificationApiClient
 from app.notify_client.status_api_client import StatusApiClient
 from app.notify_client.invite_api_client import InviteApiClient
+from app.notify_client.statistics_api_client import StatisticsApiClient
 from app.its_dangerous_session import ItsdangerousSessionInterface
 from app.asset_fingerprinter import AssetFingerprinter
 from utils.recipients import validate_phone_number, InvalidPhoneError
@@ -36,6 +37,7 @@ job_api_client = JobApiClient()
 notification_api_client = NotificationApiClient()
 status_api_client = StatusApiClient()
 invite_api_client = InviteApiClient()
+statistics_api_client = StatisticsApiClient()
 asset_fingerprinter = AssetFingerprinter()
 
 
@@ -55,6 +57,7 @@ def create_app(config_name, config_overrides=None):
     notification_api_client.init_app(application)
     status_api_client.init_app(application)
     invite_api_client.init_app(application)
+    statistics_api_client.init_app(application)
 
     login_manager.init_app(application)
     login_manager.login_view = 'main.sign_in'

app/notify_client/statistics_api_client.py

@@ -0,0 +1,18 @@
+from notifications_python_client.base import BaseAPIClient
+
+
+class StatisticsApiClient(BaseAPIClient):
+    def __init__(self, base_url=None, client_id=None, secret=None):
+        super(self.__class__, self).__init__(base_url=base_url or 'base_url',
+                                             client_id=client_id or 'client_id',
+                                             secret=secret or 'secret')
+
+    def init_app(self, app):
+        self.base_url = app.config['API_HOST_NAME']
+        self.client_id = app.config['ADMIN_CLIENT_USER_NAME']
+        self.secret = app.config['ADMIN_CLIENT_SECRET']
+
+    def get_statistics_for_service(self, service_id):
+        return self.get(
+            url='/service/{}/notifications-statistics'.format(service_id),
+        )