Add notes to WikiPage::Meta for all wikis

- Adds Wikis::UserMention model and a new table
- Adds notes support for both project- and group-level wikis by making
  WikiPage::Meta a noteable
- Includes a namespace_id attribute in user mentions copied from the
  note as a sharding key for Cells purposes

app/helpers/routing/projects_helper.rb

@@ -76,6 +76,10 @@ def release_url(entity, *args)
       project_release_url(entity.project, entity, *args)
     end
 
+    def project_wiki_page_url(entity, *args)
+      project_wiki_url(entity.project, entity.canonical_slug, *args)
+    end
+
     def edit_milestone_path(entity, *args)
       if entity.resource_parent.is_a?(Group)
         edit_group_milestone_path(entity.resource_parent, entity, *args)

app/models/concerns/noteable.rb

@@ -12,12 +12,12 @@ module Noteable
   class_methods do
     # `Noteable` class names that support replying to individual notes.
     def replyable_types
-      %w[Issue MergeRequest AbuseReport]
+      %w[Issue MergeRequest AbuseReport WikiPage::Meta]
     end
 
     # `Noteable` class names that support resolvable notes.
     def resolvable_types
-      %w[Issue MergeRequest DesignManagement::Design AbuseReport]
+      %w[Issue MergeRequest DesignManagement::Design AbuseReport WikiPage::Meta]
     end
 
     # `Noteable` class names that support creating/forwarding individual notes.

app/models/discussion_note.rb

@@ -11,7 +11,7 @@ class DiscussionNote < Note
 
   # Names of all implementers of `Noteable` that support discussions.
   def self.noteable_types
-    %w[MergeRequest Issue Commit Snippet]
+    %w[MergeRequest Issue Commit Snippet WikiPage::Meta]
   end
 
   validates :noteable_type, inclusion: { in: noteable_types }

app/models/note.rb

@@ -361,6 +361,10 @@ def for_personal_snippet?
     noteable.is_a?(PersonalSnippet)
   end
 
+  def for_wiki_page?
+    noteable_type == "WikiPage::Meta"
+  end
+
   def for_project_noteable?
     !(for_personal_snippet? || for_abuse_report? || group_level_issue?)
   end

app/models/wiki_page/meta.rb

@@ -3,6 +3,8 @@
 class WikiPage
   class Meta < ApplicationRecord
     include HasWikiPageMetaAttributes
+    include Mentionable
+    include Noteable
 
     self.table_name = 'wiki_page_meta'
 
@@ -10,15 +12,14 @@ class Meta < ApplicationRecord
     belongs_to :namespace, optional: true
 
     has_many :slugs, class_name: 'WikiPage::Slug', foreign_key: 'wiki_page_meta_id', inverse_of: :wiki_page_meta
+    has_many :notes, as: :noteable
+    has_many :user_mentions, class_name: 'Wikis::UserMention', foreign_key: 'wiki_page_meta_id',
+      inverse_of: :wiki_page_meta
 
     validate :project_or_namespace_present?
 
     alias_method :resource_parent, :project
 
-    def container_key
-      namespace.present? ? :namespace_id : :project_id
-    end
-
     def container
       project || namespace
     end
@@ -28,6 +29,14 @@ def container=(value)
       self.namespace = value if value.is_a?(Namespace)
     end
 
+    def for_group_wiki?
+      namespace_id.present?
+    end
+
+    def container_key
+      for_group_wiki? ? :namespace_id : :project_id
+    end
+
     private
 
     def project_or_namespace_present?

app/models/wikis/user_mention.rb

+# frozen_string_literal: true
+
+module Wikis
+  class UserMention < UserMention
+    self.table_name = 'wiki_page_meta_user_mentions'
+
+    belongs_to :wiki_page_meta, class_name: 'WikiPage::Meta', optional: false
+    belongs_to :note, optional: false
+
+    before_validation :set_namespace_id_from_note, on: :create
+
+    private
+
+    def set_namespace_id_from_note
+      self.namespace_id ||= note&.namespace_id
+    end
+  end
+end

db/docs/wiki_page_meta_user_mentions.yml

+---
+table_name: wiki_page_meta_user_mentions
+classes:
+- Wikis::UserMention
+feature_categories:
+- wiki
+description: User mentions in wiki page notes
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/163305
+milestone: '17.5'
+gitlab_schema: gitlab_main_cell
+sharding_key:
+  namespace_id: namespaces

db/migrate/20240917054235_create_wiki_page_user_mentions.rb

+# frozen_string_literal: true
+
+# See https://docs.gitlab.com/ee/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class CreateWikiPageUserMentions < Gitlab::Database::Migration[2.2]
+  enable_lock_retries!
+
+  milestone '17.5'
+
+  def up
+    create_table :wiki_page_meta_user_mentions do |t| # rubocop:disable Migration/EnsureFactoryForTable -- No factory needed
+      t.bigint :wiki_page_meta_id, null: false
+      t.bigint :note_id, null: false
+      t.bigint :namespace_id, null: false
+      t.bigint :mentioned_users_ids, array: true, default: nil
+      t.bigint :mentioned_projects_ids, array: true, default: nil
+      t.bigint :mentioned_groups_ids, array: true, default: nil
+
+      t.index :note_id
+      t.index :namespace_id
+      t.index [:wiki_page_meta_id, :note_id],
+        unique: true,
+        name: :index_wiki_meta_user_mentions_on_wiki_page_meta_id_and_note_id
+    end
+  end
+
+  def down
+    drop_table :wiki_page_meta_user_mentions, if_exists: true
+  end
+end

db/migrate/20240917061401_add_wiki_page_meta_foreign_key_to_wiki_page_meta_user_mentions.rb

+# frozen_string_literal: true
+
+class AddWikiPageMetaForeignKeyToWikiPageMetaUserMentions < Gitlab::Database::Migration[2.2]
+  milestone '17.5'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_foreign_key :wiki_page_meta_user_mentions, :wiki_page_meta, column: :wiki_page_meta_id,
+      on_delete: :cascade
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :wiki_page_meta_user_mentions, column: :wiki_page_meta_id
+    end
+  end
+end

db/migrate/20240917061421_add_notes_foreign_key_to_wiki_page_meta_user_mentions.rb

+# frozen_string_literal: true
+
+class AddNotesForeignKeyToWikiPageMetaUserMentions < Gitlab::Database::Migration[2.2]
+  milestone '17.5'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_foreign_key :wiki_page_meta_user_mentions, :notes, column: :note_id, on_delete: :cascade
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :wiki_page_meta_user_mentions, column: :note_id
+    end
+  end
+end

db/migrate/20240917110235_add_namespaces_foreign_key_to_wiki_page_meta_user_mentions.rb

+# frozen_string_literal: true
+
+class AddNamespacesForeignKeyToWikiPageMetaUserMentions < Gitlab::Database::Migration[2.2]
+  milestone '17.5'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_foreign_key :wiki_page_meta_user_mentions, :namespaces, column: :namespace_id, on_delete: :cascade
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :wiki_page_meta_user_mentions, column: :namespace_id
+    end
+  end
+end

db/schema_migrations/20240917054235

+9ee63c7a0b13f8eabca033494d551c498d8320144f6acec53b2bd6263e1b5152
\ No newline at end of file

db/schema_migrations/20240917061401

+ec9255f62950f75064ad2cd65c9fef6a1b4c136d4bb86238b24ed567098fb28e
\ No newline at end of file

db/schema_migrations/20240917061421

+caa78be456eebea5d9fc8cbcc0d0daa56e11f3e633f5327014702814919a073c
\ No newline at end of file

db/schema_migrations/20240917110235

+b844c5179a55387b9c0f631a9172b7b62fae98e38d8c86532dbcac2365f8a1c7
\ No newline at end of file

db/structure.sql

@@ -20571,6 +20571,25 @@ CREATE SEQUENCE wiki_page_meta_id_seq
 ALTER SEQUENCE wiki_page_meta_id_seq OWNED BY wiki_page_meta.id;
+CREATE TABLE wiki_page_meta_user_mentions (
+    id bigint NOT NULL,
+    wiki_page_meta_id bigint NOT NULL,
+    note_id bigint NOT NULL,
+    namespace_id bigint NOT NULL,
+    mentioned_users_ids bigint[],
+    mentioned_projects_ids bigint[],
+    mentioned_groups_ids bigint[]
+);
+
+CREATE SEQUENCE wiki_page_meta_user_mentions_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+ALTER SEQUENCE wiki_page_meta_user_mentions_id_seq OWNED BY wiki_page_meta_user_mentions.id;
+
 CREATE TABLE wiki_page_slugs (
     id bigint NOT NULL,
     canonical boolean DEFAULT false NOT NULL,
@@ -22731,6 +22750,8 @@ ALTER TABLE ONLY webauthn_registrations ALTER COLUMN id SET DEFAULT nextval('web
 ALTER TABLE ONLY wiki_page_meta ALTER COLUMN id SET DEFAULT nextval('wiki_page_meta_id_seq'::regclass);
+ALTER TABLE ONLY wiki_page_meta_user_mentions ALTER COLUMN id SET DEFAULT nextval('wiki_page_meta_user_mentions_id_seq'::regclass);
+
 ALTER TABLE ONLY wiki_page_slugs ALTER COLUMN id SET DEFAULT nextval('wiki_page_slugs_id_seq'::regclass);
 ALTER TABLE ONLY wiki_repository_states ALTER COLUMN id SET DEFAULT nextval('wiki_repository_states_id_seq'::regclass);
@@ -25537,6 +25558,9 @@ ALTER TABLE ONLY webauthn_registrations
 ALTER TABLE ONLY wiki_page_meta
     ADD CONSTRAINT wiki_page_meta_pkey PRIMARY KEY (id);
+ALTER TABLE ONLY wiki_page_meta_user_mentions
+    ADD CONSTRAINT wiki_page_meta_user_mentions_pkey PRIMARY KEY (id);
+
 ALTER TABLE ONLY wiki_page_slugs
     ADD CONSTRAINT wiki_page_slugs_pkey PRIMARY KEY (id);
@@ -31146,10 +31170,16 @@ CREATE UNIQUE INDEX index_webauthn_registrations_on_credential_xid ON webauthn_r
 CREATE INDEX index_webauthn_registrations_on_user_id ON webauthn_registrations USING btree (user_id);
+CREATE UNIQUE INDEX index_wiki_meta_user_mentions_on_wiki_page_meta_id_and_note_id ON wiki_page_meta_user_mentions USING btree (wiki_page_meta_id, note_id);
+
 CREATE INDEX index_wiki_page_meta_on_namespace_id ON wiki_page_meta USING btree (namespace_id);
 CREATE INDEX index_wiki_page_meta_on_project_id ON wiki_page_meta USING btree (project_id);
+CREATE INDEX index_wiki_page_meta_user_mentions_on_namespace_id ON wiki_page_meta_user_mentions USING btree (namespace_id);
+
+CREATE INDEX index_wiki_page_meta_user_mentions_on_note_id ON wiki_page_meta_user_mentions USING btree (note_id);
+
 CREATE INDEX index_wiki_page_slugs_on_project_id ON wiki_page_slugs USING btree (project_id);
 CREATE UNIQUE INDEX index_wiki_page_slugs_on_slug_and_wiki_page_meta_id ON wiki_page_slugs USING btree (slug, wiki_page_meta_id);
@@ -34103,6 +34133,9 @@ ALTER TABLE ONLY users
 ALTER TABLE ONLY analytics_devops_adoption_snapshots
     ADD CONSTRAINT fk_78c9eac821 FOREIGN KEY (namespace_id) REFERENCES namespaces(id) ON DELETE CASCADE;
+ALTER TABLE ONLY wiki_page_meta_user_mentions
+    ADD CONSTRAINT fk_7954f34107 FOREIGN KEY (namespace_id) REFERENCES namespaces(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY topics
     ADD CONSTRAINT fk_79ae18bd4b FOREIGN KEY (organization_id) REFERENCES organizations(id) ON DELETE CASCADE;
@@ -34499,12 +34532,18 @@ ALTER TABLE ONLY uploads
 ALTER TABLE ONLY deployments
     ADD CONSTRAINT fk_b9a3851b82 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
+ALTER TABLE ONLY wiki_page_meta_user_mentions
+    ADD CONSTRAINT fk_ba8a9d7f95 FOREIGN KEY (note_id) REFERENCES notes(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY project_compliance_standards_adherence
     ADD CONSTRAINT fk_baf6f6f878 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 ALTER TABLE p_ci_runner_machine_builds
     ADD CONSTRAINT fk_bb490f12fe_p FOREIGN KEY (partition_id, build_id) REFERENCES p_ci_builds(partition_id, id) ON UPDATE CASCADE ON DELETE CASCADE;
+ALTER TABLE ONLY wiki_page_meta_user_mentions
+    ADD CONSTRAINT fk_bc155eba89 FOREIGN KEY (wiki_page_meta_id) REFERENCES wiki_page_meta(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY security_orchestration_policy_rule_schedules
     ADD CONSTRAINT fk_bcbb90477f FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;

ee/app/models/ee/note.rb

@@ -51,13 +51,17 @@ def for_epic?
       noteable.is_a?(Epic)
     end
 
+    def for_group_wiki?
+      for_wiki_page? && noteable&.for_group_wiki?
+    end
+
     def for_vulnerability?
       noteable.is_a?(Vulnerability)
     end
 
     override :for_project_noteable?
     def for_project_noteable?
-      !for_epic? && super
+      !(for_epic? || for_group_wiki?) && super
     end
 
     override :banzai_render_context

ee/spec/factories/notes.rb

@@ -10,6 +10,12 @@
     trait :on_vulnerability do
       noteable { association(:vulnerability, project: project) }
     end
+
+    trait :on_group_level_wiki do
+      project { nil }
+      namespace { association :group }
+      noteable { association(:wiki_page_meta, namespace: namespace) }
+    end
   end
 end
 

ee/spec/models/note_spec.rb

@@ -297,6 +297,16 @@
     end
   end
 
+  describe '#for_group_wiki?' do
+    it 'returns true for a group-level wiki page' do
+      expect(build_stubbed(:note_on_wiki_page, :on_group_level_wiki).for_group_wiki?).to be_truthy
+    end
+
+    it 'returns false for a project-level wiki page' do
+      expect(build_stubbed(:note_on_wiki_page, :on_project_level_wiki).for_group_wiki?).to be_falsy
+    end
+  end
+
   describe '.note_starting_with' do
     it 'returns a note matching the prefix' do
       create(:note)

lib/gitlab/url_builder.rb

@@ -101,6 +101,8 @@ def note_url(note, **options)
           instance.gitlab_snippet_url(note.noteable, anchor: dom_id(note), **options)
         elsif note.for_abuse_report?
           instance.admin_abuse_report_url(note.noteable, anchor: dom_id(note), **options)
+        elsif note.for_wiki_page?
+          instance.project_wiki_page_url(note.noteable, anchor: dom_id(note), **options)
         end
       end