Allow filtering of notification stats by days

https://www.pivotaltracker.com/story/show/117920839

On the dashboard we want to show counts of notifications sent in the
last 7 days, plus today. So the API enpoint needs to accept an argument
to limit how many days worth of statistics it will return.

This is a bit fiddly at the DAO level because the date is just stored as
a string.

app/dao/notifications_dao.py

@@ -69,6 +69,19 @@ def dao_get_notification_statistics_for_service_and_day(service_id, day):
     ).order_by(desc(NotificationStatistics.day)).first()
 
 
+def dao_get_notification_statistics_for_service_and_previous_days(service_id, limit_days):
+    return NotificationStatistics.query.filter_by(
+        service_id=service_id
+    ).filter(
+        NotificationStatistics.day.in_((
+            (date.today() - timedelta(days=days_ago)).strftime('%Y-%m-%d')
+            for days_ago in range(0, limit_days + 1)
+        ))
+    ).order_by(
+        desc(NotificationStatistics.day)
+    ).all()
+
+
 def dao_get_template_statistics_for_service(service_id, limit_days=None):
     filter = [TemplateStatistics.service_id == service_id]
     if limit_days:

app/notifications_statistics/rest.py

@@ -4,7 +4,8 @@ from flask import (
 )
 
 from app.dao.notifications_dao import (
-    dao_get_notification_statistics_for_service
+    dao_get_notification_statistics_for_service,
+    dao_get_notification_statistics_for_service_and_previous_days
 )
 from app.schemas import notifications_statistics_schema
 
@@ -19,7 +20,20 @@ register_errors(notifications_statistics)
 
 
 @notifications_statistics.route('', methods=['GET'])
-def get_all_templates_for_service(service_id):
-    templates = dao_get_notification_statistics_for_service(service_id=service_id)
-    data, errors = notifications_statistics_schema.dump(templates, many=True)
+def get_all_notification_statistics_for_service(service_id):
+
+    if request.args.get('limit_days'):
+        try:
+            statistics = dao_get_notification_statistics_for_service_and_previous_days(
+                service_id=service_id,
+                limit_days=int(request.args['limit_days'])
+            )
+        except ValueError as e:
+            error = '{} is not an integer'.format(request.args['limit_days'])
+            current_app.logger.error(error)
+            return jsonify(result="error", message={'limit_days': [error]}), 400
+    else:
+        statistics = dao_get_notification_statistics_for_service(service_id=service_id)
+
+    data, errors = notifications_statistics_schema.dump(statistics, many=True)
     return jsonify(data=data)

tests/app/dao/test_notification_dao.py

@@ -26,6 +26,7 @@ from app.dao.notifications_dao import (
     delete_notifications_created_more_than_a_day_ago,
     delete_notifications_created_more_than_a_week_ago,
     dao_get_notification_statistics_for_service_and_day,
+    dao_get_notification_statistics_for_service_and_previous_days,
     update_notification_status_by_id,
     update_notification_reference_by_id,
     update_notification_status_by_reference,
@@ -279,6 +280,46 @@ def test_should_be_empty_list_if_no_statistics_for_a_service(sample_service):
     assert len(dao_get_notification_statistics_for_service(sample_service.id)) == 0
 
 
+def test_should_be_able_to_get_all_statistics_for_a_service_for_several_days_previous(sample_template):
+    data = {
+        'to': '+44709123456',
+        'service': sample_template.service,
+        'service_id': sample_template.service.id,
+        'template': sample_template,
+        'template_id': sample_template.id
+    }
+
+    today = datetime.utcnow()
+    seven_days_ago = datetime.utcnow() - timedelta(days=7)
+    eight_days_ago = datetime.utcnow() - timedelta(days=8)
+    data.update({
+        'created_at': today
+    })
+    notification_1 = Notification(**data)
+    data.update({
+        'created_at': seven_days_ago
+    })
+    notification_2 = Notification(**data)
+    data.update({
+        'created_at': eight_days_ago
+    })
+    notification_3 = Notification(**data)
+    dao_create_notification(notification_1, sample_template.template_type)
+    dao_create_notification(notification_2, sample_template.template_type)
+    dao_create_notification(notification_3, sample_template.template_type)
+
+    stats = dao_get_notification_statistics_for_service_and_previous_days(
+        sample_template.service.id, 7
+    )
+    assert len(stats) == 2
+    assert stats[0].emails_requested == 0
+    assert stats[0].sms_requested == 1
+    assert stats[0].day == today.strftime(DATE_FORMAT)
+    assert stats[1].emails_requested == 0
+    assert stats[1].sms_requested == 1
+    assert stats[1].day == seven_days_ago.strftime(DATE_FORMAT)
+
+
 def test_save_notification_creates_sms_and_template_stats(sample_template, sample_job):
     assert Notification.query.count() == 0
     assert NotificationStatistics.query.count() == 0