3 files changed, 38 insertions, 1 deletions
diff --git a/app/models/incident_management/timeline_event.rb b/app/models/incident_management/timeline_event.rb
index dd0d3c6585d..735d4e4298c 100644
--- a/app/models/incident_management/timeline_event.rb
+++ b/app/models/incident_management/timeline_event.rb
@@ -18,7 +18,13 @@ module IncidentManagement
 
     validates :project, :incident, :occurred_at, presence: true
     validates :action, presence: true, length: { maximum: 128 }
-    validates :note, :note_html, presence: true, length: { maximum: 10_000 }
+    validates :note, presence: true, length: { maximum: 10_000 }
+    validates :note_html, length: { maximum: 10_000 }
+
+    has_many :timeline_event_tag_links, class_name: 'IncidentManagement::TimelineEventTagLink'
+    has_many :timeline_event_tags,
+      class_name: 'IncidentManagement::TimelineEventTag',
+      through: :timeline_event_tag_links
 
     scope :order_occurred_at_asc_id_asc, -> { reorder(occurred_at: :asc, id: :asc) }
   end
diff --git a/app/models/incident_management/timeline_event_tag.rb b/app/models/incident_management/timeline_event_tag.rb
new file mode 100644
index 00000000000..cde3afcaa16
--- /dev/null
+++ b/app/models/incident_management/timeline_event_tag.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module IncidentManagement
+  class TimelineEventTag < ApplicationRecord
+    self.table_name = 'incident_management_timeline_event_tags'
+
+    belongs_to :project, inverse_of: :incident_management_timeline_event_tags
+
+    has_many :timeline_event_tag_links,
+      class_name: 'IncidentManagement::TimelineEventTagLink'
+
+    has_many :timeline_events,
+      class_name: 'IncidentManagement::TimelineEvent',
+      through: :timeline_event_tag_links
+
+    validates :name, presence: true, format: { with: /\A[^,]+\z/ }
+    validates :name, uniqueness: { scope: :project_id }
+    validates :name, length: { maximum: 255 }
+  end
+end
diff --git a/app/models/incident_management/timeline_event_tag_link.rb b/app/models/incident_management/timeline_event_tag_link.rb
new file mode 100644
index 00000000000..912339717a8
--- /dev/null
+++ b/app/models/incident_management/timeline_event_tag_link.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module IncidentManagement
+  class TimelineEventTagLink < ApplicationRecord
+    self.table_name = 'incident_management_timeline_event_tag_links'
+
+    belongs_to :timeline_event_tag, class_name: 'IncidentManagement::TimelineEventTag'
+
+    belongs_to :timeline_event, class_name: 'IncidentManagement::TimelineEvent'
+  end
+end