feat(nimbus): Summary page timeline (#11393)

Because

- We want to show the timeline on the new summary page

This commit

- Adds new status timeline

Note: On the same timeline, in the next PR, I will add the functionality
to go back from preview to draft or preview to launch

Fixes #11361 
<img width="1589" alt="Screenshot 2024-09-19 at 5 15 39 PM"
src="https://github.com/user-attachments/assets/60532b4f-b305-4c3a-ade0-5b22bbce53c6">
<img width="1589" alt="Screenshot 2024-09-19 at 5 10 35 PM"
src="https://github.com/user-attachments/assets/ea32031f-0455-415b-8a26-46dd4986ee37">
<img width="1589" alt="Screenshot 2024-09-19 at 5 09 49 PM"
src="https://github.com/user-attachments/assets/cdab6df7-ed3b-442b-bed8-2f921e3a0a89">
<img width="1589" alt="Screenshot 2024-09-19 at 5 08 56 PM"
src="https://github.com/user-attachments/assets/58898acc-047a-498f-ab82-c0b2b661566f">

Future design 
![image
(7)](https://github.com/user-attachments/assets/ce31d166-9dc9-4dba-a754-76f0293a58eb)

experimenter/experimenter/experiments/models.py

@@ -612,10 +612,55 @@ class NimbusExperiment(NimbusConstants, TargetingConstants, FilterMixin, models.
             branches = branches.exclude(id=self.reference_branch.id)
         return list(branches)
 
+    @property
+    def is_draft(self):
+        return self.status == self.Status.DRAFT
+
+    @property
+    def is_review(self):
+        return self.is_draft and self.publish_status == self.PublishStatus.REVIEW
+
+    @property
+    def is_preview(self):
+        return self.status == self.Status.PREVIEW
+
+    @property
+    def is_live(self):
+        return self.status == self.Status.LIVE
+
+    @property
+    def is_complete(self):
+        return self.status == self.Status.COMPLETE
+
     @property
     def is_started(self):
         return self.status in (self.Status.LIVE, self.Status.COMPLETE)
 
+    @property
+    def draft_date(self):
+        if change := self.changes.all().order_by("changed_on").first():
+            return change.changed_on.date()
+
+    @property
+    def preview_date(self):
+        if change := (
+            self.changes.filter(new_status=self.Status.PREVIEW)
+            .order_by("changed_on")
+            .first()
+        ):
+            return change.changed_on.date()
+
+    @property
+    def review_date(self):
+        if change := (
+            self.changes.filter(
+                new_status=self.Status.DRAFT, new_publish_status=self.PublishStatus.REVIEW
+            )
+            .order_by("changed_on")
+            .first()
+        ):
+            return change.changed_on.date()
+
     @property
     def start_date(self):
         if self._start_date is not None:
@@ -747,6 +792,35 @@ class NimbusExperiment(NimbusConstants, TargetingConstants, FilterMixin, models.
             return (self.computed_end_date - self.enrollment_start_date).days
         return self.proposed_duration
 
+    def timeline(self):
+        return [
+            {
+                "label": self.Status.DRAFT,
+                "date": self.draft_date,
+                "is_active": self.is_draft,
+            },
+            {
+                "label": self.Status.PREVIEW,
+                "date": self.preview_date,
+                "is_active": self.is_preview,
+            },
+            {
+                "label": self.PublishStatus.REVIEW,
+                "date": self.review_date,
+                "is_active": self.is_review,
+            },
+            {
+                "label": self.Status.LIVE,
+                "date": self.start_date,
+                "is_active": self.is_live,
+            },
+            {
+                "label": self.Status.COMPLETE,
+                "date": self.computed_end_date,
+                "is_active": self.is_complete,
+            },
+        ]
+
     @property
     def should_end(self):
         if self.proposed_end_date:

experimenter/experimenter/experiments/tests/test_models.py

@@ -1640,6 +1640,116 @@ class TestNimbusExperiment(TestCase):
             ),
         )
 
+    def test_draft_date_uses_first_changelog_if_no_start_date(self):
+        experiment = NimbusExperimentFactory.create(_start_date=None)
+        first_changelog = NimbusChangeLogFactory.create(
+            experiment=experiment, changed_on=datetime.datetime(2023, 2, 1)
+        )
+        self.assertEqual(experiment.draft_date, first_changelog.changed_on.date())
+
+    def test_preview_date_returns_first_preview_change(self):
+        experiment = NimbusExperimentFactory.create()
+        preview_change = NimbusChangeLogFactory.create(
+            experiment=experiment,
+            old_status=NimbusExperiment.Status.DRAFT,
+            new_status=NimbusExperiment.Status.PREVIEW,
+            changed_on=datetime.datetime(2023, 3, 1),
+        )
+        self.assertEqual(experiment.preview_date, preview_change.changed_on.date())
+
+    def test_preview_date_returns_none_if_no_preview_status(self):
+        experiment = NimbusExperimentFactory.create()
+        NimbusChangeLogFactory.create(
+            experiment=experiment,
+            old_status=NimbusExperiment.Status.DRAFT,
+            new_status=NimbusExperiment.Status.DRAFT,
+            changed_on=datetime.datetime(2023, 4, 1),
+        )
+        self.assertIsNone(experiment.preview_date)
+
+    def test_review_date_returns_first_review_change(self):
+        experiment = NimbusExperimentFactory.create()
+        review_change = NimbusChangeLogFactory.create(
+            experiment=experiment,
+            old_publish_status=NimbusExperiment.Status.PREVIEW,
+            new_publish_status=NimbusExperiment.PublishStatus.REVIEW,
+            changed_on=datetime.datetime(2023, 5, 1),
+        )
+        self.assertEqual(experiment.review_date, review_change.changed_on.date())
+
+    def test_review_date_returns_none_if_no_review_status(self):
+        experiment = NimbusExperimentFactory.create()
+        NimbusChangeLogFactory.create(
+            experiment=experiment,
+            old_publish_status=NimbusExperiment.Status.DRAFT,
+            new_publish_status=NimbusExperiment.Status.PREVIEW,
+            changed_on=datetime.datetime(2023, 6, 1),
+        )
+        self.assertIsNone(experiment.review_date)
+
+    def test_timeline_dates_includes_correct_status_dates_and_flags(self):
+        experiment = NimbusExperimentFactory.create_with_lifecycle(
+            lifecycle=NimbusExperimentFactory.Lifecycles.LIVE_APPROVE,
+        )
+        NimbusChangeLogFactory.create(
+            experiment=experiment,
+            new_status=NimbusExperiment.Status.DRAFT,
+            changed_on=datetime.datetime(2023, 1, 1),
+        )
+
+        NimbusChangeLogFactory.create(
+            experiment=experiment,
+            old_status=NimbusExperiment.Status.DRAFT,
+            new_status=NimbusExperiment.Status.PREVIEW,
+            changed_on=datetime.datetime(2023, 3, 1),
+        )
+
+        NimbusChangeLogFactory.create(
+            experiment=experiment,
+            old_publish_status=NimbusExperiment.Status.PREVIEW,
+            new_publish_status=NimbusExperiment.PublishStatus.REVIEW,
+            changed_on=datetime.datetime(2023, 4, 1),
+        )
+        timeline = experiment.timeline()
+        expected_timeline = [
+            {
+                "label": "Draft",
+                "date": experiment.draft_date,
+                "is_active": False,
+            },
+            {
+                "label": "Preview",
+                "date": experiment.preview_date,
+                "is_active": False,
+            },
+            {
+                "label": "Review",
+                "date": experiment.review_date,
+                "is_active": False,
+            },
+            {"label": "Live", "date": experiment.start_date, "is_active": True},
+            {
+                "label": "Complete",
+                "date": experiment.computed_end_date,
+                "is_active": False,
+            },
+        ]
+        for i, expected in enumerate(expected_timeline):
+            self.assertEqual(timeline[i]["label"], expected["label"])
+            self.assertEqual(timeline[i]["date"], expected["date"])
+            self.assertEqual(timeline[i]["is_active"], expected["is_active"])
+
+    def test_timeline_dates_complete_is_active_when_status_is_complete(self):
+        experiment = NimbusExperimentFactory.create_with_lifecycle(
+            lifecycle=NimbusExperimentFactory.Lifecycles.ENDING_APPROVE_APPROVE,
+            end_date=datetime.date(2023, 7, 1),
+        )
+        timeline = experiment.timeline()
+        self.assertTrue(
+            timeline[-1]["is_active"]
+        )  # Check if the last status "Complete" is active
+        self.assertEqual(timeline[-1]["date"], experiment.end_date)
+
     def test_monitoring_dashboard_url_is_valid_when_experiment_not_begun(self):
         experiment = NimbusExperimentFactory.create(
             slug="experiment",

experimenter/experimenter/nimbus_ui_new/templates/nimbus_experiments/detail.html

@@ -8,18 +8,13 @@
 {% block main_content %}
   <div class="container-fluid">
     <!-- Experiment Details Card -->
-    <div class="card mb-3">
-      <div class="card-header">
-        <h4>Experiment Details</h4>
-      </div>
-      <div class="card-body">
-        <p>
-          <strong>Slug:</strong> {{ experiment.slug }}
-        </p>
-        <p>
-          <strong>Name:</strong> {{ experiment.name }}
-        </p>
+    <div class="row">
+      <div class="col-6">
+        <h4 class="mb-0">{{ experiment.name }}</h4>
+        <p class="text-secondary">{{ experiment.slug }}</p>
       </div>
+      {% include "nimbus_experiments/timeline.html" %}
+
     </div>
     <!-- Takeaways Card -->
     {% include "nimbus_experiments/takeaways_card.html" %}

experimenter/experimenter/nimbus_ui_new/templates/nimbus_experiments/timeline.html

@@ -0,0 +1,10 @@
+<div class="col-6">
+  <ul class="list-group list-group-horizontal justify-content-between mb-3">
+    {% for status in experiment.timeline %}
+      <li class="list-group-item flex-fill text-center d-flex flex-column justify-content-center {% if status.is_active %}bg-primary text-white{% endif %}">
+        <strong>{{ status.label }}</strong>
+        <small>{{ status.date|default:'---' }}</small>
+      </li>
+    {% endfor %}
+  </ul>
+</div>