From 1b5aaed10a2a0eb05aeb1c52679d6948e3a985e7 Mon Sep 17 00:00:00 2001
From: Katie Smith <katie.smith@digital.cabinet-office.gov.uk>
Date: Mon, 19 Feb 2018 14:00:33 +0000
Subject: [PATCH] Create DAO for daily sorted letter model

---
 app/dao/daily_sorted_letter_dao.py            | 37 +++++++++++++++
 tests/app/dao/test_daily_sorted_letter_dao.py | 47 +++++++++++++++++++
 tests/app/db.py                               | 16 ++++++-
 3 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 app/dao/daily_sorted_letter_dao.py
 create mode 100644 tests/app/dao/test_daily_sorted_letter_dao.py

diff --git a/app/dao/daily_sorted_letter_dao.py b/app/dao/daily_sorted_letter_dao.py
new file mode 100644
index 000000000..3afad4b2a
--- /dev/null
+++ b/app/dao/daily_sorted_letter_dao.py
@@ -0,0 +1,37 @@
+from datetime import datetime
+
+from sqlalchemy.dialects.postgresql import insert
+
+from app import db
+from app.dao.dao_utils import transactional
+from app.models import DailySortedLetter
+
+
+def dao_get_daily_sorted_letter_by_billing_day(billing_day):
+    return DailySortedLetter.query.filter_by(
+        billing_day=billing_day
+    ).first()
+
+
+@transactional
+def dao_create_or_update_daily_sorted_letter(new_daily_sorted_letter):
+    '''
+    This uses the Postgres upsert to avoid race conditions when two threads try and insert
+    at the same row. The excluded object refers to values that we tried to insert but were
+    rejected.
+    http://docs.sqlalchemy.org/en/latest/dialects/postgresql.html#insert-on-conflict-upsert
+    '''
+    table = DailySortedLetter.__table__
+    stmt = insert(table).values(
+        billing_day=new_daily_sorted_letter.billing_day,
+        unsorted_count=new_daily_sorted_letter.unsorted_count,
+        sorted_count=new_daily_sorted_letter.sorted_count)
+    stmt = stmt.on_conflict_do_update(
+        index_elements=[table.c.billing_day],
+        set_={
+            'unsorted_count': table.c.unsorted_count + stmt.excluded.unsorted_count,
+            'sorted_count': table.c.sorted_count + stmt.excluded.sorted_count,
+            'updated_at': datetime.utcnow()
+        }
+    )
+    db.session.connection().execute(stmt)
diff --git a/tests/app/dao/test_daily_sorted_letter_dao.py b/tests/app/dao/test_daily_sorted_letter_dao.py
new file mode 100644
index 000000000..2a4ceb318
--- /dev/null
+++ b/tests/app/dao/test_daily_sorted_letter_dao.py
@@ -0,0 +1,47 @@
+from datetime import date
+
+from app.dao.daily_sorted_letter_dao import (
+    dao_create_or_update_daily_sorted_letter,
+    dao_get_daily_sorted_letter_by_billing_day,
+)
+from app.models import DailySortedLetter
+from tests.app.db import create_daily_sorted_letter
+
+
+def test_dao_get_daily_sorted_letter_by_billing_day(notify_db, notify_db_session):
+    billing_day = date(2018, 2, 1)
+    other_day = date(2017, 9, 8)
+
+    daily_sorted_letters = create_daily_sorted_letter(billing_day=billing_day)
+
+    assert dao_get_daily_sorted_letter_by_billing_day(billing_day) == daily_sorted_letters
+    assert not dao_get_daily_sorted_letter_by_billing_day(other_day)
+
+
+def test_dao_create_or_update_daily_sorted_letter_creates_a_new_entry(notify_db, notify_db_session):
+    billing_day = date(2018, 2, 1)
+    dsl = DailySortedLetter(billing_day=billing_day, unsorted_count=2, sorted_count=0)
+    dao_create_or_update_daily_sorted_letter(dsl)
+
+    daily_sorted_letter = dao_get_daily_sorted_letter_by_billing_day(billing_day)
+
+    assert daily_sorted_letter.billing_day == billing_day
+    assert daily_sorted_letter.unsorted_count == 2
+    assert daily_sorted_letter.sorted_count == 0
+    assert not daily_sorted_letter.updated_at
+
+
+def test_dao_create_or_update_daily_sorted_letter_updates_an_existing_entry(
+    notify_db,
+    notify_db_session
+):
+    create_daily_sorted_letter(unsorted_count=2, sorted_count=3)
+
+    dsl = DailySortedLetter(billing_day=date(2018, 1, 18), unsorted_count=5, sorted_count=17)
+    dao_create_or_update_daily_sorted_letter(dsl)
+
+    daily_sorted_letter = dao_get_daily_sorted_letter_by_billing_day(dsl.billing_day)
+
+    assert daily_sorted_letter.unsorted_count == 7
+    assert daily_sorted_letter.sorted_count == 20
+    assert daily_sorted_letter.updated_at
diff --git a/tests/app/db.py b/tests/app/db.py
index 6a09413a8..b159976da 100644
--- a/tests/app/db.py
+++ b/tests/app/db.py
@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, date
 import uuid
 
 from app import db
@@ -9,6 +9,7 @@ from app.dao.service_sms_sender_dao import update_existing_sms_sender_with_inbou
 from app.dao.invited_org_user_dao import save_invited_org_user
 from app.models import (
     ApiKey,
+    DailySortedLetter,
     InboundSms,
     InboundNumber,
     Job,
@@ -506,3 +507,16 @@ def create_invited_org_user(organisation, invited_by, email_address='invite@exam
     )
     save_invited_org_user(invited_org_user)
     return invited_org_user
+
+
+def create_daily_sorted_letter(billing_day=date(2018, 1, 18), unsorted_count=0, sorted_count=0):
+    daily_sorted_letter = DailySortedLetter(
+        billing_day=billing_day,
+        unsorted_count=unsorted_count,
+        sorted_count=sorted_count
+    )
+
+    db.session.add(daily_sorted_letter)
+    db.session.commit()
+
+    return daily_sorted_letter