Update Slack "invite" feature to use direct paging (#2562)

# What this PR does

Refactors the "invite" functionality in Slack to use direct paging and
be more consistent with the web UI and `/escalate` Slack command.

## Screenshots

### Alert group buttons

Before:

<img width="609" alt="Screenshot 2023-07-17 at 22 40 47"
src="https://github.com/grafana/oncall/assets/20116910/68fad5a4-5011-4d74-b1c7-362bdb4f8cf0">


After (replace "Invite..." dropdown with "Responders" button, swap it
with the silence button):
<img width="587" alt="Screenshot 2023-07-17 at 22 37 19"
src="https://github.com/grafana/oncall/assets/20116910/50b42057-f46b-4558-ab1c-56c34a15af5e">


### What happens when clicking on "Responders"

The following modal opens up with a list of currently paged users and
inputs to page more users/schedules:

<img width="514" alt="Screenshot 2023-07-17 at 22 37 52"
src="https://github.com/grafana/oncall/assets/20116910/70bd2853-d459-4343-8b25-8519ac0098f7">

This is supposed to be the Slack equivalent of this part of the web UI:

<img width="601" alt="Screenshot 2023-07-17 at 22 47 17"
src="https://github.com/grafana/oncall/assets/20116910/101e1229-a5c4-404f-8388-eceee3e4820f">


## Which issue(s) this PR fixes

#2336

## Checklist

- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Changed
+
+- Update Slack "invite" feature to use direct paging by @vadimkerr ([#2562](https://github.com/grafana/oncall/pull/2562))
+
 ## v1.3.14 (2023-07-17)
 
 ### Changed

engine/apps/alerts/incident_appearance/renderers/slack_renderer.py

@@ -213,12 +213,6 @@ def _get_buttons_blocks(self):
                     },
                 )
 
-                if self.alert_group.invitations.filter(is_active=True).count() < 5:
-                    action_id = ScenarioStep.get_step("distribute_alerts", "InviteOtherPersonToIncident").routing_uid()
-                    text = "Invite..."
-                    invitation_element = self._get_select_user_element(action_id, text=text)
-                    buttons.append(invitation_element)
-
                 if not self.alert_group.silenced:
                     silence_options = [
                         {
@@ -245,6 +239,15 @@ def _get_buttons_blocks(self):
                         },
                     )
 
+                buttons.append(
+                    {
+                        "text": {"type": "plain_text", "text": "Responders", "emoji": True},
+                        "type": "button",
+                        "value": self._alert_group_action_value(),
+                        "action_id": ScenarioStep.get_step("manage_responders", "StartManageResponders").routing_uid(),
+                    },
+                )
+
                 attach_button = {
                     "text": {"type": "plain_text", "text": "Attach to ...", "emoji": True},
                     "type": "button",

engine/apps/alerts/models/alert_group.py

@@ -498,6 +498,23 @@ def declare_incident_link(self) -> str:
     def happened_while_maintenance(self):
         return self.root_alert_group is not None and self.root_alert_group.maintenance_uuid is not None
 
+    def get_paged_users(self) -> QuerySet[User]:
+        from apps.alerts.models import AlertGroupLogRecord
+
+        users_ids = set()
+        for log_record in self.log_records.filter(
+            type__in=(AlertGroupLogRecord.TYPE_DIRECT_PAGING, AlertGroupLogRecord.TYPE_UNPAGE_USER)
+        ):
+            # filter paging events, track still active escalations
+            info = log_record.get_step_specific_info()
+            user_id = info.get("user") if info else None
+            if user_id is not None:
+                users_ids.add(
+                    user_id
+                ) if log_record.type == AlertGroupLogRecord.TYPE_DIRECT_PAGING else users_ids.discard(user_id)
+
+        return User.objects.filter(public_primary_key__in=users_ids)
+
     def _get_response_time(self):
         """Return response_time based on current alert group status."""
         response_time = None

engine/apps/alerts/paging.py

@@ -28,7 +28,7 @@
 
 def _trigger_alert(
     organization: Organization,
-    team: Team,
+    team: Team | None,
     title: str,
     message: str,
     from_user: User,
@@ -133,7 +133,7 @@ def check_user_availability(user: User) -> list[dict[str, Any]]:
 
 def direct_paging(
     organization: Organization,
-    team: Team,
+    team: Team | None,
     from_user: User,
     title: str = None,
     message: str = None,

engine/apps/api/serializers/alert_group.py

@@ -6,8 +6,7 @@
 
 from apps.alerts.incident_appearance.renderers.classic_markdown_renderer import AlertGroupClassicMarkdownRenderer
 from apps.alerts.incident_appearance.renderers.web_renderer import AlertGroupWebRenderer
-from apps.alerts.models import AlertGroup, AlertGroupLogRecord
-from apps.user_management.models import User
+from apps.alerts.models import AlertGroup
 from common.api_helpers.custom_fields import TeamPrimaryKeyRelatedField
 from common.api_helpers.mixins import EagerLoadingMixin
 
@@ -216,17 +215,4 @@ def get_limited_alerts(self, obj):
         return AlertSerializer(alerts, many=True).data
 
     def get_paged_users(self, obj):
-        users_ids = set()
-        for log_record in obj.log_records.filter(
-            type__in=(AlertGroupLogRecord.TYPE_DIRECT_PAGING, AlertGroupLogRecord.TYPE_UNPAGE_USER)
-        ):
-            # filter paging events, track still active escalations
-            info = log_record.get_step_specific_info()
-            user_id = info.get("user") if info else None
-            if user_id is not None:
-                users_ids.add(
-                    user_id
-                ) if log_record.type == AlertGroupLogRecord.TYPE_DIRECT_PAGING else users_ids.discard(user_id)
-
-        users = [u.short() for u in User.objects.filter(public_primary_key__in=users_ids)]
-        return users
+        return [u.short() for u in obj.get_paged_users()]

engine/apps/slack/scenarios/distribute_alerts.py

@@ -212,6 +212,11 @@ def process_scenario(self, slack_user_identity, slack_team_identity, payload):
 
 
 class InviteOtherPersonToIncident(AlertGroupActionsMixin, scenario_step.ScenarioStep):
+    """
+    THIS SCENARIO STEP IS DEPRECATED AND WILL BE REMOVED IN THE FUTURE.
+    Check out apps/slack/scenarios/manage_responders.py for the new version that uses direct paging.
+    """
+
     REQUIRED_PERMISSIONS = [RBACPermission.Permissions.CHATOPS_WRITE]
 
     def process_scenario(self, slack_user_identity, slack_team_identity, payload):
@@ -490,6 +495,11 @@ def process_signal(self, log_record):
 
 
 class StopInvitationProcess(AlertGroupActionsMixin, scenario_step.ScenarioStep):
+    """
+    THIS SCENARIO STEP IS DEPRECATED AND WILL BE REMOVED IN THE FUTURE.
+    Check out apps/slack/scenarios/manage_responders.py for the new version that uses direct paging.
+    """
+
     REQUIRED_PERMISSIONS = [RBACPermission.Permissions.CHATOPS_WRITE]
 
     def process_scenario(self, slack_user_identity, slack_team_identity, payload):