Add function to send PDF letter

This function checks various permissions, downloads the PDF from the
transient bucket, creates the notification then moves the letter to the
'normal' bucket.

tests/app/service/test_send_pdf_letter_notification.py

@@ -0,0 +1,102 @@
+import uuid
+
+import pytest
+from freezegun import freeze_time
+
+from app.dao.notifications_dao import get_notification_by_id
+from app.models import EMAIL_TYPE, LETTER_TYPE, UPLOAD_LETTERS
+from app.service.send_notification import send_pdf_letter_notification
+from app.v2.errors import BadRequestError, TooManyRequestsError
+from notifications_utils.s3 import S3ObjectNotFound
+from tests.app.db import create_service
+
+
+@pytest.mark.parametrize('permissions', [
+    [EMAIL_TYPE],
+    [LETTER_TYPE],
+    [UPLOAD_LETTERS],
+])
+def test_send_pdf_letter_notification_raises_error_if_service_does_not_have_permission(
+    notify_db_session,
+    fake_uuid,
+    permissions,
+):
+    service = create_service(service_permissions=permissions)
+    post_data = {'filename': 'valid.pdf', 'created_by': fake_uuid, 'file_id': fake_uuid}
+
+    with pytest.raises(BadRequestError):
+        send_pdf_letter_notification(service.id, post_data)
+
+
+def test_send_pdf_letter_notification_raises_error_if_service_is_over_daily_message_limit(
+    mocker,
+    sample_service_full_permissions,
+    fake_uuid,
+):
+    mocker.patch(
+        'app.service.send_notification.check_service_over_daily_message_limit',
+        side_effect=TooManyRequestsError(10))
+    post_data = {'filename': 'valid.pdf', 'created_by': fake_uuid, 'file_id': fake_uuid}
+
+    with pytest.raises(TooManyRequestsError):
+        send_pdf_letter_notification(sample_service_full_permissions.id, post_data)
+
+
+def test_send_pdf_letter_notification_validates_created_by(
+    sample_service_full_permissions, fake_uuid, sample_user
+):
+    post_data = {'filename': 'valid.pdf', 'created_by': sample_user.id, 'file_id': fake_uuid}
+
+    with pytest.raises(BadRequestError):
+        send_pdf_letter_notification(sample_service_full_permissions.id, post_data)
+
+
+def test_send_pdf_letter_notification_raises_error_when_pdf_is_not_in_transient_letter_bucket(
+    mocker,
+    sample_service_full_permissions,
+    fake_uuid,
+    notify_user,
+):
+    user = sample_service_full_permissions.users[0]
+    post_data = {'filename': 'valid.pdf', 'created_by': user.id, 'file_id': fake_uuid}
+    mocker.patch('app.service.send_notification.utils_s3download', side_effect=S3ObjectNotFound({}, ''))
+
+    with pytest.raises(S3ObjectNotFound):
+        send_pdf_letter_notification(sample_service_full_permissions.id, post_data)
+
+
+@freeze_time("2019-08-02 11:00:00")
+def test_send_pdf_letter_notification_creates_notification_and_moves_letter(
+    mocker,
+    sample_service_full_permissions,
+    notify_user,
+):
+    user = sample_service_full_permissions.users[0]
+    filename = 'valid.pdf'
+    file_id = uuid.uuid4()
+    post_data = {'filename': filename, 'created_by': user.id, 'file_id': file_id}
+
+    mocker.patch('app.service.send_notification.utils_s3download')
+    mocker.patch('app.service.send_notification.get_page_count', return_value=1)
+    s3_mock = mocker.patch('app.service.send_notification.move_uploaded_pdf_to_letters_bucket')
+
+    result = send_pdf_letter_notification(sample_service_full_permissions.id, post_data)
+
+    notification = get_notification_by_id(file_id)
+
+    assert notification.id == file_id
+    assert notification.api_key_id is None
+    assert notification.client_reference == filename
+    assert notification.created_by_id == user.id
+    assert notification.postage == 'second'
+    assert notification.notification_type == LETTER_TYPE
+    assert notification.billable_units == 1
+    assert notification.to == filename
+    assert notification.service_id == sample_service_full_permissions.id
+
+    assert result == {'id': str(notification.id)}
+
+    s3_mock.assert_called_once_with(
+        'service-{}/{}.pdf'.format(sample_service_full_permissions.id, file_id),
+        '2019-08-02/NOTIFY.{}.D.2.C.C.20190802110000.PDF'.format(notification.reference)
+    )