Post ActivityPub message when a creator adds a new model

app/jobs/activity/creator_added_model_job.rb

@@ -0,0 +1,16 @@
+class Activity::CreatorAddedModelJob < ApplicationJob
+  queue_as :activity
+
+  def perform(model_id)
+    model = Model.find(model_id)
+    Comment.create!(
+      system: true,
+      commentable: model,
+      commenter: model.creator,
+      comment: I18n.t("jobs.activity.creator_added_model.comment", # rubocop:disable I18n/RailsI18n/DecorateStringFormattingUsingInterpolation
+        model_name: model.name,
+        url: model.actor.profile_url,
+        tags: model.tag_list.map { |t| "##{t}" }.join(" "))
+    )
+  end
+end

app/models/concerns/followable.rb

@@ -6,8 +6,6 @@ module Followable
 
   included do
     delegate :following_followers, to: :actor
-    after_commit :post_creation_activity, on: :create
-    after_commit :post_update_activity, on: :update
 
     after_followed :auto_accept
   end
@@ -22,30 +20,6 @@ def followed_by?(follower)
 
   private
 
-  def post_creation_activity
-    user = permitted_users.with_permission("own").first || SiteSettings.default_user
-    return if user.nil?
-    user.create_actor_if_missing
-    Federails::Activity.create!(
-      actor: user.actor,
-      action: "Create",
-      entity: actor,
-      created_at: created_at
-    )
-  end
-
-  def post_update_activity
-    return if actor&.activities_as_entity&.where(created_at: TIMEOUT.minutes.ago..)&.count&.> 0
-    user = permitted_users.with_permission("own").first || SiteSettings.default_user
-    return if user.nil?
-    Federails::Activity.create!(
-      actor: user.actor,
-      action: "Update",
-      entity: actor,
-      created_at: updated_at
-    )
-  end
-
   def auto_accept
     actor.following_followers.where(status: "pending").find_each { |x| x.accept! }
   end

app/models/model.rb

@@ -27,7 +27,9 @@ class Model < ApplicationRecord
   # In Rails 7.1 we will be able to do this instead:
   # normalizes :license, with: -> license { license.blank? ? nil : license }
 
+  after_create :post_creation_activity
   before_update :move_files, if: :need_to_move_files?
+  after_update :post_update_activity
   after_commit :check_integrity, on: :update
 
   validates :name, presence: true
@@ -196,4 +198,16 @@ def move_files
   def check_integrity
     Scan::CheckModelIntegrityJob.set(wait: 5.seconds).perform_later(id)
   end
+
+  def post_creation_activity
+    if creator.present?
+      Activity::CreatorAddedModelJob.set(wait: 5.seconds).perform_later(id)
+    end
+  end
+
+  def post_update_activity
+    if creator_previously_changed?
+      Activity::CreatorAddedModelJob.set(wait: 5.seconds).perform_later(id)
+    end
+  end
 end

config/locales/en.yml

@@ -280,6 +280,14 @@ en:
         placeholder: What are you looking for?
       update_actor: updated by %{name} %{time} ago
   jobs:
+    activity:
+      creator_added_model:
+        comment: |
+          I've just added a new model: "%{model_name}".
+
+          Find it at %{url}
+
+          %{tags}
     analysis:
       analyse_model_file:
         detect_duplicates: Detecting duplicate files

db/migrate/20241009122540_add_system_to_comments.rb

@@ -0,0 +1,5 @@
+class AddSystemToComments < ActiveRecord::Migration[7.1]
+  def change
+    add_column :comments, :system, :boolean, null: false, default: false
+  end
+end

spec/jobs/activity/creator_added_model_job_spec.rb

@@ -0,0 +1,48 @@
+require "rails_helper"
+
+RSpec.describe Activity::CreatorAddedModelJob do
+  let(:creator) { create(:creator) }
+  let(:model) { create(:model, creator: creator, tag_list: "tag1, tag2") }
+
+  it "adds a comment" do
+    expect { described_class.new.perform(model.id) }.to change(Comment, :count).by(1)
+  end
+
+  it "ends up queueing an ActivityPub publish job" do
+    expect { described_class.new.perform(model.id) }.to have_enqueued_job Federails::NotifyInboxJob
+  end
+
+  context "with a comment" do
+    subject(:comment) { model.comments.first }
+
+    before do
+      described_class.new.perform(model.id)
+    end
+
+    it "sets creator as author" do
+      expect(comment.commenter).to eq creator
+    end
+
+    it "sets model as the subject" do
+      expect(comment.commentable).to eq model
+    end
+
+    it "marks comment as a system comment" do
+      expect(comment.system).to be true
+    end
+
+    it "includes model name in text" do
+      expect(comment.comment).to include model.name
+    end
+
+    it "includes tags in text as hashtags" do
+      model.tag_list.each do |tag|
+        expect(comment.comment).to include "##{tag}"
+      end
+    end
+
+    it "includes URL in text" do
+      expect(comment.comment).to include "http://localhost:3214/models/#{model.public_id}"
+    end
+  end
+end

spec/models/concerns/followable_shared.rb

@@ -15,31 +15,4 @@
       expect(target.followers.count).to eq 1
     end
   end
-
-  context "when being created" do
-    before do
-      create(:admin)
-    end
-
-    it "posts an activity" do
-      expect { create(described_class.to_s.underscore.to_sym) }.to change(Federails::Activity, :count).by(1)
-    end
-  end
-
-  context "when being updated" do
-    let!(:entity) { create(described_class.to_s.underscore.to_sym) }
-
-    before do
-      create(:admin)
-    end
-
-    it "posts an activity after update" do
-      expect { entity.update caption: "test" }.to change(Federails::Activity, :count).by(1)
-    end
-
-    it "doesn't posts an activity after update if there's already been one recently" do
-      entity.update caption: "change"
-      expect { entity.update caption: "test" }.not_to change(Federails::Activity, :count)
-    end
-  end
 end

spec/models/model_spec.rb

@@ -385,4 +385,18 @@
       expect(file).to have_received(:delete_from_disk_and_destroy).once
     end
   end
+
+  context "when making changes" do
+    it "queues creator-specific model creation job when model is created if a creator is set" do
+      model = create(:model, creator: create(:creator))
+      expect(Activity::CreatorAddedModelJob).to have_been_enqueued.with(model.id)
+    end
+
+    it "queues creator-specific model creation job when model is updated if a creator has changed" do
+      model = create(:model)
+      ActiveJob::Base.queue_adapter.enqueued_jobs.clear
+      model.update(creator: create(:creator))
+      expect(Activity::CreatorAddedModelJob).to have_been_enqueued.with(model.id)
+    end
+  end
 end