And an endpoint to get uploaded letters for a day

Because we won’t be showing uploaded letters individually on the uploads
page any more we need a way of listing them. This should be by printing
day, to match how we’re grouping them on the uploads page.

The response matches a normal `get_notifications` response so we can
reuse the same code in the admin app.

tests/app/dao/test_uploads_dao.py

@@ -1,7 +1,7 @@
 from datetime import datetime, timedelta
 from freezegun import freeze_time
 
-from app.dao.uploads_dao import dao_get_uploads_by_service_id
+from app.dao.uploads_dao import dao_get_uploads_by_service_id, dao_get_uploaded_letters_by_print_date
 from app.models import LETTER_TYPE, JOB_STATUS_IN_PROGRESS
 from tests.app.db import create_job, create_service, create_service_data_retention, create_template, create_notification
 
@@ -302,3 +302,56 @@ def test_get_uploads_is_paginated(sample_template):
 def test_get_uploads_returns_empty_list(sample_service):
     items = dao_get_uploads_by_service_id(sample_service.id).items
     assert items == []
+
+
+@freeze_time('2020-02-02 14:00')
+def test_get_uploaded_letters_by_print_date(sample_template):
+    letter_template = create_uploaded_template(sample_template.service)
+
+    # Letters for the previous day’s run
+    for i in range(3):
+        create_uploaded_letter(
+            letter_template, sample_template.service, status='delivered',
+            created_at=datetime.utcnow().replace(day=1, hour=17, minute=29, second=59)
+        )
+
+    # Letters from yesterday that rolled into today’s run
+    for i in range(30):
+        create_uploaded_letter(
+            letter_template, sample_template.service, status='delivered',
+            created_at=datetime.utcnow().replace(day=1, hour=17, minute=30, second=0)
+        )
+
+    # Letters that just made today’s run
+    for i in range(30):
+        create_uploaded_letter(
+            letter_template, sample_template.service, status='delivered',
+            created_at=datetime.utcnow().replace(hour=17, minute=29, second=59)
+        )
+
+    # Letters that just missed today’s run
+    for i in range(3):
+        create_uploaded_letter(
+            letter_template, sample_template.service, status='delivered',
+            created_at=datetime.utcnow().replace(hour=17, minute=30, second=0)
+        )
+
+    result = dao_get_uploaded_letters_by_print_date(
+        sample_template.service_id,
+        datetime.utcnow(),
+    )
+    assert result.total == 60
+    assert len(result.items) == 50
+    assert result.has_next is True
+    assert result.has_prev is False
+
+    result = dao_get_uploaded_letters_by_print_date(
+        sample_template.service_id,
+        datetime.utcnow(),
+        page=10,
+        page_size=2,
+    )
+    assert result.total == 60
+    assert len(result.items) == 2
+    assert result.has_next is True
+    assert result.has_prev is True