From ad70af72aa40033eb60edfac104af9788b1bfbfe Mon Sep 17 00:00:00 2001
From: Jon Massey <jon.massey@thedatalab.org>
Date: Thu, 29 Feb 2024 17:15:32 +0000
Subject: [PATCH] Sort homepage workspaces by most recent activity

i.e. workspace updated or jobrequest created
---
 jobserver/models/workspace.py                 | 21 +++++++++++++-
 jobserver/views/index.py                      |  3 +-
 tests/unit/jobserver/models/test_workspace.py | 28 +++++++++++++++++++
 tests/unit/jobserver/views/test_index.py      |  9 ++++--
 4 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/jobserver/models/workspace.py b/jobserver/models/workspace.py
index 29f8d2d9e..b1630d3e8 100644
--- a/jobserver/models/workspace.py
+++ b/jobserver/models/workspace.py
@@ -1,6 +1,7 @@
 import structlog
 from django.db import connection, models
-from django.db.models import Q
+from django.db.models import Max, Q
+from django.db.models.functions import Greatest
 from django.urls import reverse
 from django.utils import timezone
 from furl import furl
@@ -9,6 +10,22 @@
 logger = structlog.get_logger(__name__)
 
 
+class WorkspaceQuerySet(models.QuerySet):
+    def with_most_recent_activity_at(self):
+        return (
+            self.prefetch_related("job_requests")
+            .annotate(
+                last_jobrequest_created_at=Max("job_requests__created_at"),
+                max_updated_at=Max("updated_at"),
+            )
+            .annotate(
+                most_recent_activity_at=Greatest(
+                    "last_jobrequest_created_at", "max_updated_at"
+                )
+            )
+        )
+
+
 class Workspace(models.Model):
     """Models a working directory on a Backend server."""
 
@@ -55,6 +72,8 @@ class Workspace(models.Model):
         related_name="workspaces_updated",
     )
 
+    objects = WorkspaceQuerySet.as_manager()
+
     class Meta:
         constraints = [
             # mirror Django's validate_slug validator into the database
diff --git a/jobserver/views/index.py b/jobserver/views/index.py
index 5887f8a4d..a7e3a1928 100644
--- a/jobserver/views/index.py
+++ b/jobserver/views/index.py
@@ -49,7 +49,8 @@ def get(self, request, *args, **kwargs):
                 is_archived=False, project__in=self.request.user.projects.all()
             )
             .select_related("project")
-            .order_by("-created_at")
+            .with_most_recent_activity_at()
+            .order_by("-most_recent_activity_at")
         )
 
         counts = {
diff --git a/tests/unit/jobserver/models/test_workspace.py b/tests/unit/jobserver/models/test_workspace.py
index c13d9be97..5d723b0b3 100644
--- a/tests/unit/jobserver/models/test_workspace.py
+++ b/tests/unit/jobserver/models/test_workspace.py
@@ -416,3 +416,31 @@ def test_workspace_is_interactive():
 def test_workspace_str():
     workspace = WorkspaceFactory(name="corellian-engineering-corporation")
     assert str(workspace) == "corellian-engineering-corporation"
+
+
+def test_workspace_with_most_recent_activity_at_jobrequest():
+    workspace = WorkspaceFactory()
+    JobRequestFactory(workspace=workspace)
+
+    w = Workspace.objects.with_most_recent_activity_at().get(pk=workspace.pk)
+
+    assert w.most_recent_activity_at == w.last_jobrequest_created_at
+
+
+def test_workspace_with_most_recent_activity_at_no_jobrequest():
+    workspace = WorkspaceFactory()
+
+    w = Workspace.objects.with_most_recent_activity_at().get(pk=workspace.pk)
+
+    assert w.most_recent_activity_at == w.updated_at
+
+
+def test_workspace_with_most_recent_activity_at_updated_and_jobrequest():
+    workspace = WorkspaceFactory()
+    JobRequestFactory(workspace=workspace)
+    workspace.purpose = "update the workspace"
+    workspace.save()
+
+    w = Workspace.objects.with_most_recent_activity_at().get(pk=workspace.pk)
+
+    assert w.most_recent_activity_at == w.updated_at
diff --git a/tests/unit/jobserver/views/test_index.py b/tests/unit/jobserver/views/test_index.py
index 36a80a738..c972b41c6 100644
--- a/tests/unit/jobserver/views/test_index.py
+++ b/tests/unit/jobserver/views/test_index.py
@@ -23,7 +23,9 @@ def test_index_authenticated(
 
     project1 = ProjectFactory()
     project_membership(project=project1, user=user)
-    workspace1 = WorkspaceFactory(project=project1)
+    workspace1, workspace2, workspace3, workspace4, workspace5 = (
+        WorkspaceFactory.create_batch(5, project=project1)
+    )
     JobRequestFactory(workspace=workspace1, created_by=user)
     JobRequestFactory(workspace=workspace1, created_by=user)
 
@@ -36,9 +38,10 @@ def test_index_authenticated(
 
     # create a lot of objects the user has access to so we can check our limits
     # are working as expected
-    JobRequestFactory.create_batch(10, workspace=workspace1)
+    for w in [workspace1, workspace2, workspace3, workspace4, workspace5]:
+        JobRequestFactory.create_batch(10, workspace=w)
     project_memberships(10, user=user)
-    WorkspaceFactory.create_batch(10, project=project2)
+    WorkspaceFactory.create_batch(6, project=project2)
 
     request = rf.get("/")
     request.user = user