Add support for FASP data sharing (#34415)

app/controllers/api/fasp/data_sharing/v0/backfill_requests_controller.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class Api::Fasp::DataSharing::V0::BackfillRequestsController < Api::Fasp::BaseController
+  def create
+    backfill_request = current_provider.fasp_backfill_requests.new(backfill_request_params)
+
+    respond_to do |format|
+      format.json do
+        if backfill_request.save
+          render json: { backfillRequest: { id: backfill_request.id } }, status: 201
+        else
+          head 422
+        end
+      end
+    end
+  end
+
+  private
+
+  def backfill_request_params
+    params
+      .permit(:category, :maxCount)
+      .to_unsafe_h
+      .transform_keys { |k| k.to_s.underscore }
+  end
+end

app/controllers/api/fasp/data_sharing/v0/continuations_controller.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class Api::Fasp::DataSharing::V0::ContinuationsController < Api::Fasp::BaseController
+  def create
+    backfill_request = current_provider.fasp_backfill_requests.find(params[:backfill_request_id])
+    Fasp::BackfillWorker.perform_async(backfill_request.id)
+
+    head 204
+  end
+end

app/controllers/api/fasp/data_sharing/v0/event_subscriptions_controller.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class Api::Fasp::DataSharing::V0::EventSubscriptionsController < Api::Fasp::BaseController
+  def create
+    subscription = current_provider.fasp_subscriptions.create!(subscription_params)
+
+    render json: { subscription: { id: subscription.id } }, status: 201
+  end
+
+  def destroy
+    subscription = current_provider.fasp_subscriptions.find(params[:id])
+    subscription.destroy
+
+    head 204
+  end
+
+  private
+
+  def subscription_params
+    params
+      .permit(:category, :subscriptionType, :maxBatchSize, threshold: {})
+      .to_unsafe_h
+      .transform_keys { |k| k.to_s.underscore }
+  end
+end

app/lib/fasp/request.rb

@@ -32,6 +32,7 @@ class Fasp::Request
   def request_headers(verb, url, body = '')
     result = {
       'accept' => 'application/json',
+      'content-type' => 'application/json',
       'content-digest' => content_digest(body),
     }
     result.merge(signature_headers(verb, url, result))

app/models/account.rb

@@ -85,6 +85,7 @@ class Account < ApplicationRecord
   include Account::Associations
   include Account::Avatar
   include Account::Counters
+  include Account::FaspConcern
   include Account::FinderConcern
   include Account::Header
   include Account::Interactions

app/models/concerns/account/fasp_concern.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Account::FaspConcern
+  extend ActiveSupport::Concern
+
+  included do
+    after_commit :announce_new_account_to_subscribed_fasp, on: :create
+    after_commit :announce_updated_account_to_subscribed_fasp, on: :update
+    after_commit :announce_deleted_account_to_subscribed_fasp, on: :destroy
+  end
+
+  private
+
+  def announce_new_account_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless discoverable?
+
+    uri = ActivityPub::TagManager.instance.uri_for(self)
+    Fasp::AnnounceAccountLifecycleEventWorker.perform_async(uri, 'new')
+  end
+
+  def announce_updated_account_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless discoverable? || saved_change_to_discoverable?
+
+    uri = ActivityPub::TagManager.instance.uri_for(self)
+    Fasp::AnnounceAccountLifecycleEventWorker.perform_async(uri, 'update')
+  end
+
+  def announce_deleted_account_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless discoverable?
+
+    uri = ActivityPub::TagManager.instance.uri_for(self)
+    Fasp::AnnounceAccountLifecycleEventWorker.perform_async(uri, 'delete')
+  end
+end

app/models/concerns/favourite/fasp_concern.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module Favourite::FaspConcern
+  extend ActiveSupport::Concern
+
+  included do
+    after_commit :announce_trends_to_subscribed_fasp, on: :create
+  end
+
+  private
+
+  def announce_trends_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+
+    Fasp::AnnounceTrendWorker.perform_async(status_id, 'favourite')
+  end
+end

app/models/concerns/status/fasp_concern.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+module Status::FaspConcern
+  extend ActiveSupport::Concern
+
+  included do
+    after_commit :announce_new_content_to_subscribed_fasp, on: :create
+    after_commit :announce_updated_content_to_subscribed_fasp, on: :update
+    after_commit :announce_deleted_content_to_subscribed_fasp, on: :destroy
+    after_commit :announce_trends_to_subscribed_fasp, on: :create
+  end
+
+  private
+
+  def announce_new_content_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless account_indexable? && public_visibility?
+
+    # We need the uri here, but it is set in another `after_commit`
+    # callback. Hooks included from modules are run before the ones
+    # in the class itself and can neither be reordered nor is there
+    # a way to declare dependencies.
+    store_uri if uri.nil?
+    Fasp::AnnounceContentLifecycleEventWorker.perform_async(uri, 'new')
+  end
+
+  def announce_updated_content_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless account_indexable? && public_visibility?
+
+    Fasp::AnnounceContentLifecycleEventWorker.perform_async(uri, 'update')
+  end
+
+  def announce_deleted_content_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless account_indexable? && public_visibility?
+
+    Fasp::AnnounceContentLifecycleEventWorker.perform_async(uri, 'delete')
+  end
+
+  def announce_trends_to_subscribed_fasp
+    return unless Mastodon::Feature.fasp_enabled?
+    return unless account_indexable?
+
+    candidate_id, trend_source =
+      if reblog_of_id
+        [reblog_of_id, 'reblog']
+      elsif in_reply_to_id
+        [in_reply_to_id, 'reply']
+      end
+    Fasp::AnnounceTrendWorker.perform_async(candidate_id, trend_source) if candidate_id
+  end
+end

app/models/fasp.rb

@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 module Fasp
+  DATA_CATEGORIES = %w(account content).freeze
+
   def self.table_name_prefix
     'fasp_'
   end

app/models/fasp/backfill_request.rb

@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: fasp_backfill_requests
+#
+#  id               :bigint(8)        not null, primary key
+#  category         :string           not null
+#  cursor           :string
+#  fulfilled        :boolean          default(FALSE), not null
+#  max_count        :integer          default(100), not null
+#  created_at       :datetime         not null
+#  updated_at       :datetime         not null
+#  fasp_provider_id :bigint(8)        not null
+#
+class Fasp::BackfillRequest < ApplicationRecord
+  belongs_to :fasp_provider, class_name: 'Fasp::Provider'
+
+  validates :category, presence: true, inclusion: Fasp::DATA_CATEGORIES
+  validates :max_count, presence: true,
+                        numericality: { only_integer: true }
+
+  after_commit :queue_fulfillment_job, on: :create
+
+  def next_objects
+    @next_objects ||= base_scope.to_a
+  end
+
+  def next_uris
+    next_objects.map { |o| ActivityPub::TagManager.instance.uri_for(o) }
+  end
+
+  def more_objects_available?
+    return false if next_objects.empty?
+
+    base_scope.where(id: ...(next_objects.last.id)).any?
+  end
+
+  def advance!
+    if more_objects_available?
+      update!(cursor: next_objects.last.id)
+    else
+      update!(fulfilled: true)
+    end
+  end
+
+  private
+
+  def base_scope
+    result = category_scope.limit(max_count).order(id: :desc)
+    result = result.where(id: ...cursor) if cursor.present?
+    result
+  end
+
+  def category_scope
+    case category
+    when 'account'
+      Account.discoverable.without_instance_actor
+    when 'content'
+      Status.indexable
+    end
+  end
+
+  def queue_fulfillment_job
+    Fasp::BackfillWorker.perform_async(id)
+  end
+end

app/models/fasp/provider.rb

@@ -22,7 +22,9 @@
 class Fasp::Provider < ApplicationRecord
   include DebugConcern
 
+  has_many :fasp_backfill_requests, inverse_of: :fasp_provider, class_name: 'Fasp::BackfillRequest', dependent: :delete_all
   has_many :fasp_debug_callbacks, inverse_of: :fasp_provider, class_name: 'Fasp::DebugCallback', dependent: :delete_all
+  has_many :fasp_subscriptions, inverse_of: :fasp_provider, class_name: 'Fasp::Subscription', dependent: :delete_all
 
   validates :name, presence: true
   validates :base_url, presence: true, url: true

app/models/fasp/subscription.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: fasp_subscriptions
+#
+#  id                  :bigint(8)        not null, primary key
+#  category            :string           not null
+#  max_batch_size      :integer          not null
+#  subscription_type   :string           not null
+#  threshold_likes     :integer
+#  threshold_replies   :integer
+#  threshold_shares    :integer
+#  threshold_timeframe :integer
+#  created_at          :datetime         not null
+#  updated_at          :datetime         not null
+#  fasp_provider_id    :bigint(8)        not null
+#
+class Fasp::Subscription < ApplicationRecord
+  TYPES = %w(lifecycle trends).freeze
+
+  belongs_to :fasp_provider, class_name: 'Fasp::Provider'
+
+  validates :category, presence: true, inclusion: Fasp::DATA_CATEGORIES
+  validates :subscription_type, presence: true,
+                                inclusion: TYPES
+
+  scope :category_content, -> { where(category: 'content') }
+  scope :category_account, -> { where(category: 'account') }
+  scope :lifecycle, -> { where(subscription_type: 'lifecycle') }
+  scope :trends, -> { where(subscription_type: 'trends') }
+
+  def threshold=(threshold)
+    self.threshold_timeframe = threshold['timeframe'] || 15
+    self.threshold_shares    = threshold['shares'] || 3
+    self.threshold_likes     = threshold['likes'] || 3
+    self.threshold_replies   = threshold['replies'] || 3
+  end
+
+  def timeframe_start
+    threshold_timeframe.minutes.ago
+  end
+end

app/models/favourite.rb

@@ -13,6 +13,7 @@
 
 class Favourite < ApplicationRecord
   include Paginable
+  include Favourite::FaspConcern
 
   update_index('statuses', :status)
 

app/models/status.rb

@@ -36,6 +36,7 @@ class Status < ApplicationRecord
   include Discard::Model
   include Paginable
   include RateLimitable
+  include Status::FaspConcern
   include Status::FetchRepliesConcern
   include Status::SafeReblogInsert
   include Status::SearchConcern
@@ -181,7 +182,7 @@ class Status < ApplicationRecord
                    ],
                    thread: :account
 
-  delegate :domain, to: :account, prefix: true
+  delegate :domain, :indexable?, to: :account, prefix: true
 
   REAL_TIME_WINDOW = 6.hours
 

app/workers/fasp/announce_account_lifecycle_event_worker.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+class Fasp::AnnounceAccountLifecycleEventWorker
+  include Sidekiq::Worker
+
+  sidekiq_options queue: 'fasp', retry: 5
+
+  def perform(uri, event_type)
+    Fasp::Subscription.includes(:fasp_provider).category_account.lifecycle.each do |subscription|
+      announce(subscription, uri, event_type)
+    end
+  end
+
+  private
+
+  def announce(subscription, uri, event_type)
+    Fasp::Request.new(subscription.fasp_provider).post('/data_sharing/v0/announcements', body: {
+      source: {
+        subscription: {
+          id: subscription.id.to_s,
+        },
+      },
+      category: 'account',
+      eventType: event_type,
+      objectUris: [uri],
+    })
+  end
+end

app/workers/fasp/announce_content_lifecycle_event_worker.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+class Fasp::AnnounceContentLifecycleEventWorker
+  include Sidekiq::Worker
+
+  sidekiq_options queue: 'fasp', retry: 5
+
+  def perform(uri, event_type)
+    Fasp::Subscription.includes(:fasp_provider).category_content.lifecycle.each do |subscription|
+      announce(subscription, uri, event_type)
+    end
+  end
+
+  private
+
+  def announce(subscription, uri, event_type)
+    Fasp::Request.new(subscription.fasp_provider).post('/data_sharing/v0/announcements', body: {
+      source: {
+        subscription: {
+          id: subscription.id.to_s,
+        },
+      },
+      category: 'content',
+      eventType: event_type,
+      objectUris: [uri],
+    })
+  end
+end

app/workers/fasp/announce_trend_worker.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+class Fasp::AnnounceTrendWorker
+  include Sidekiq::Worker
+
+  sidekiq_options queue: 'fasp', retry: 5
+
+  def perform(status_id, trend_source)
+    status = ::Status.includes(:account).find(status_id)
+    return unless status.account.indexable?
+
+    Fasp::Subscription.includes(:fasp_provider).category_content.trends.each do |subscription|
+      announce(subscription, status.uri) if trending?(subscription, status, trend_source)
+    end
+  rescue ActiveRecord::RecordNotFound
+    # status might not exist anymore, in which case there is nothing to do
+  end
+
+  private
+
+  def trending?(subscription, status, trend_source)
+    scope = scope_for(status, trend_source)
+    threshold = threshold_for(subscription, trend_source)
+    scope.where(created_at: subscription.timeframe_start..).count >= threshold
+  end
+
+  def scope_for(status, trend_source)
+    case trend_source
+    when 'favourite'
+      status.favourites
+    when 'reblog'
+      status.reblogs
+    when 'reply'
+      status.replies
+    end
+  end
+
+  def threshold_for(subscription, trend_source)
+    case trend_source
+    when 'favourite'
+      subscription.threshold_likes
+    when 'reblog'
+      subscription.threshold_shares
+    when 'reply'
+      subscription.threshold_replies
+    end
+  end
+
+  def announce(subscription, uri)
+    Fasp::Request.new(subscription.fasp_provider).post('/data_sharing/v0/announcements', body: {
+      source: {
+        subscription: {
+          id: subscription.id.to_s,
+        },
+      },
+      category: 'content',
+      eventType: 'trending',
+      objectUris: [uri],
+    })
+  end
+end

app/workers/fasp/backfill_worker.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+class Fasp::BackfillWorker
+  include Sidekiq::Worker
+
+  sidekiq_options queue: 'fasp', retry: 5
+
+  def perform(backfill_request_id)
+    backfill_request = Fasp::BackfillRequest.find(backfill_request_id)
+
+    announce(backfill_request)
+
+    backfill_request.advance!
+  rescue ActiveRecord::RecordNotFound
+    # ignore missing backfill requests
+  end
+
+  private
+
+  def announce(backfill_request)
+    Fasp::Request.new(backfill_request.fasp_provider).post('/data_sharing/v0/announcements', body: {
+      source: {
+        backfillRequest: {
+          id: backfill_request.id.to_s,
+        },
+      },
+      category: backfill_request.category,
+      objectUris: backfill_request.next_uris,
+      moreObjectsAvailable: backfill_request.more_objects_available?,
+    })
+  end
+end

config/routes/fasp.rb

@@ -10,6 +10,16 @@ namespace :api, format: false do
       end
     end
 
+    namespace :data_sharing do
+      namespace :v0 do
+        resources :backfill_requests, only: [:create] do
+          resource :continuation, only: [:create]
+        end
+
+        resources :event_subscriptions, only: [:create, :destroy]
+      end
+    end
+
     resource :registration, only: [:create]
   end
 end

config/sidekiq.yml

@@ -7,6 +7,7 @@
   - [mailers, 2]
   - [pull]
   - [scheduler]
+  - [fasp]
 
 :scheduler:
   :listened_queues_only: true

db/migrate/20241213130230_create_fasp_subscriptions.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class CreateFaspSubscriptions < ActiveRecord::Migration[7.2]
+  def change
+    create_table :fasp_subscriptions do |t|
+      t.string :category, null: false
+      t.string :subscription_type, null: false
+      t.integer :max_batch_size, null: false
+      t.integer :threshold_timeframe
+      t.integer :threshold_shares
+      t.integer :threshold_likes
+      t.integer :threshold_replies
+      t.references :fasp_provider, null: false, foreign_key: true
+
+      t.timestamps
+    end
+  end
+end

db/migrate/20250103131909_create_fasp_backfill_requests.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class CreateFaspBackfillRequests < ActiveRecord::Migration[7.2]
+  def change
+    create_table :fasp_backfill_requests do |t|
+      t.string :category, null: false
+      t.integer :max_count, null: false, default: 100
+      t.string :cursor
+      t.boolean :fulfilled, null: false, default: false
+      t.references :fasp_provider, null: false, foreign_key: true
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -445,6 +445,17 @@ ActiveRecord::Schema[8.0].define(version: 2025_04_28_095029) do
     t.index ["domain"], name: "index_email_domain_blocks_on_domain", unique: true
   end
 
+  create_table "fasp_backfill_requests", force: :cascade do |t|
+    t.string "category", null: false
+    t.integer "max_count", default: 100, null: false
+    t.string "cursor"
+    t.boolean "fulfilled", default: false, null: false
+    t.bigint "fasp_provider_id", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["fasp_provider_id"], name: "index_fasp_backfill_requests_on_fasp_provider_id"
+  end
+
   create_table "fasp_debug_callbacks", force: :cascade do |t|
     t.bigint "fasp_provider_id", null: false
     t.string "ip", null: false
@@ -471,6 +482,20 @@ ActiveRecord::Schema[8.0].define(version: 2025_04_28_095029) do
     t.index ["base_url"], name: "index_fasp_providers_on_base_url", unique: true
   end
 
+  create_table "fasp_subscriptions", force: :cascade do |t|
+    t.string "category", null: false
+    t.string "subscription_type", null: false
+    t.integer "max_batch_size", null: false
+    t.integer "threshold_timeframe"
+    t.integer "threshold_shares"
+    t.integer "threshold_likes"
+    t.integer "threshold_replies"
+    t.bigint "fasp_provider_id", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["fasp_provider_id"], name: "index_fasp_subscriptions_on_fasp_provider_id"
+  end
+
   create_table "favourites", force: :cascade do |t|
     t.datetime "created_at", precision: nil, null: false
     t.datetime "updated_at", precision: nil, null: false
@@ -1322,7 +1347,9 @@ ActiveRecord::Schema[8.0].define(version: 2025_04_28_095029) do
   add_foreign_key "custom_filter_statuses", "statuses", on_delete: :cascade
   add_foreign_key "custom_filters", "accounts", on_delete: :cascade
   add_foreign_key "email_domain_blocks", "email_domain_blocks", column: "parent_id", on_delete: :cascade
+  add_foreign_key "fasp_backfill_requests", "fasp_providers"
   add_foreign_key "fasp_debug_callbacks", "fasp_providers"
+  add_foreign_key "fasp_subscriptions", "fasp_providers"
   add_foreign_key "favourites", "accounts", name: "fk_5eb6c2b873", on_delete: :cascade
   add_foreign_key "favourites", "statuses", name: "fk_b0e856845e", on_delete: :cascade
   add_foreign_key "featured_tags", "accounts", on_delete: :cascade

spec/fabricators/account_fabricator.rb

@@ -15,4 +15,5 @@ Fabricator(:account) do
   user                { |attrs| attrs[:domain].nil? ? Fabricate.build(:user, account: nil) : nil }
   uri                 { |attrs| attrs[:domain].nil? ? '' : "https://#{attrs[:domain]}/users/#{attrs[:username]}" }
   discoverable        true
+  indexable           true
 end

spec/fabricators/fasp/backfill_request_fabricator.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+Fabricator(:fasp_backfill_request, from: 'Fasp::BackfillRequest') do
+  category      'content'
+  max_count     10
+  cursor        nil
+  fulfilled     false
+  fasp_provider
+end

spec/fabricators/fasp/subscription_fabricator.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+Fabricator(:fasp_subscription, from: 'Fasp::Subscription') do
+  category            'content'
+  subscription_type   'lifecycle'
+  max_batch_size      10
+  fasp_provider
+end

spec/models/concerns/account/fasp_concern_spec.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Account::FaspConcern, feature: :fasp do
+  describe '#create' do
+    let(:discoverable_attributes) do
+      Fabricate.attributes_for(:account).except('user_id')
+    end
+    let(:undiscoverable_attributes) do
+      discoverable_attributes.merge('discoverable' => false)
+    end
+
+    context 'when account is discoverable' do
+      it 'queues a job to notify provider' do
+        Account.create(discoverable_attributes)
+
+        expect(Fasp::AnnounceAccountLifecycleEventWorker).to have_enqueued_sidekiq_job
+      end
+    end
+
+    context 'when account is not discoverable' do
+      it 'does not queue a job' do
+        Account.create(undiscoverable_attributes)
+
+        expect(Fasp::AnnounceAccountLifecycleEventWorker).to_not have_enqueued_sidekiq_job
+      end
+    end
+  end
+
+  describe '#update' do
+    before do
+      # Create account and clear sidekiq queue so we only catch
+      # jobs queued as part of the update
+      account
+      Sidekiq::Worker.clear_all
+    end
+
+    context 'when account is discoverable' do
+      let(:account) { Fabricate(:account, domain: 'example.com') }
+
+      it 'queues a job to notify provider' do
+        expect { account.touch }.to enqueue_sidekiq_job(Fasp::AnnounceAccountLifecycleEventWorker)
+      end
+    end
+
+    context 'when account was discoverable before' do
+      let(:account) { Fabricate(:account, domain: 'example.com') }
+
+      it 'queues a job to notify provider' do
+        expect do
+          account.update(discoverable: false)
+        end.to enqueue_sidekiq_job(Fasp::AnnounceAccountLifecycleEventWorker)
+      end
+    end
+
+    context 'when account has not been discoverable' do
+      let(:account) { Fabricate(:account, domain: 'example.com', discoverable: false) }
+
+      it 'does not queue a job' do
+        expect { account.touch }.to_not enqueue_sidekiq_job(Fasp::AnnounceAccountLifecycleEventWorker)
+      end
+    end
+  end
+
+  describe '#destroy' do
+    context 'when account is discoverable' do
+      let(:account) { Fabricate(:account, domain: 'example.com') }
+
+      it 'queues a job to notify provider' do
+        expect { account.destroy }.to enqueue_sidekiq_job(Fasp::AnnounceAccountLifecycleEventWorker)
+      end
+    end
+
+    context 'when account is not discoverable' do
+      let(:account) { Fabricate(:account, domain: 'example.com', discoverable: false) }
+
+      it 'does not queue a job' do
+        expect { account.destroy }.to_not enqueue_sidekiq_job(Fasp::AnnounceAccountLifecycleEventWorker)
+      end
+    end
+  end
+end

spec/models/concerns/favourite/fasp_concern_spec.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Favourite::FaspConcern, feature: :fasp do
+  describe '#create' do
+    it 'queues a job to notify provider' do
+      expect { Fabricate(:favourite) }.to enqueue_sidekiq_job(Fasp::AnnounceTrendWorker)
+    end
+  end
+end

spec/models/concerns/status/fasp_concern_spec.rb

@@ -0,0 +1,123 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Status::FaspConcern, feature: :fasp do
+  describe '#create' do
+    context 'when account is indexable' do
+      let(:account) { Fabricate(:account, domain: 'example.com') }
+
+      context 'when status is public' do
+        it 'queues a job to notify provider of new status' do
+          expect do
+            Fabricate(:status, account:)
+          end.to enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+        end
+      end
+
+      context 'when status is not public' do
+        it 'does not queue a job' do
+          expect do
+            Fabricate(:status, account:, visibility: :unlisted)
+          end.to_not enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+        end
+      end
+
+      context 'when status is in reply to another' do
+        it 'queues a job to notify provider of possible trend' do
+          parent = Fabricate(:status)
+          expect do
+            Fabricate(:status, account:, thread: parent)
+          end.to enqueue_sidekiq_job(Fasp::AnnounceTrendWorker)
+        end
+      end
+
+      context 'when status is a reblog of another' do
+        it 'queues a job to notify provider of possible trend' do
+          original = Fabricate(:status, account:)
+          expect do
+            Fabricate(:status, account:, reblog: original)
+          end.to enqueue_sidekiq_job(Fasp::AnnounceTrendWorker)
+        end
+      end
+    end
+
+    context 'when account is not indexable' do
+      let(:account) { Fabricate(:account, indexable: false) }
+
+      it 'does not queue a job' do
+        expect do
+          Fabricate(:status, account:)
+        end.to_not enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+      end
+    end
+  end
+
+  describe '#update' do
+    before do
+      # Create status and clear sidekiq queues to only catch
+      # jobs queued due to the update
+      status
+      Sidekiq::Worker.clear_all
+    end
+
+    context 'when account is indexable' do
+      let(:account) { Fabricate(:account, domain: 'example.com') }
+      let(:status) { Fabricate(:status, account:, visibility:) }
+
+      context 'when status is public' do
+        let(:visibility) { :public }
+
+        it 'queues a job to notify provider' do
+          expect { status.touch }.to enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+        end
+      end
+
+      context 'when status has not been public' do
+        let(:visibility) { :unlisted }
+
+        it 'does not queue a job' do
+          expect do
+            status.touch
+          end.to_not enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+        end
+      end
+    end
+
+    context 'when account is not indexable' do
+      let(:account) { Fabricate(:account, domain: 'example.com', indexable: false) }
+      let(:status) { Fabricate(:status, account:) }
+
+      it 'does not queue a job' do
+        expect { status.touch }.to_not enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+      end
+    end
+  end
+
+  describe '#destroy' do
+    let(:status) { Fabricate(:status, account:) }
+
+    before do
+      # Create status and clear sidekiq queues to only catch
+      # jobs queued due to the update
+      status
+      Sidekiq::Worker.clear_all
+    end
+
+    context 'when account is indexable' do
+      let(:account) { Fabricate(:account, domain: 'example.com') }
+
+      it 'queues a job to notify provider' do
+        expect { status.destroy }.to enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+      end
+    end
+
+    context 'when account is not indexable' do
+      let(:account) { Fabricate(:account, domain: 'example.com', indexable: false) }
+
+      it 'does not queue a job' do
+        expect { status.destroy }.to_not enqueue_sidekiq_job(Fasp::AnnounceContentLifecycleEventWorker)
+      end
+    end
+  end
+end

spec/models/fasp/backfill_request_spec.rb

@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Fasp::BackfillRequest do
+  describe '#next_objects' do
+    let(:account) { Fabricate(:account) }
+    let!(:statuses) { Fabricate.times(3, :status, account:).sort_by(&:id) }
+
+    context 'with a new backfill request' do
+      subject { Fabricate(:fasp_backfill_request, max_count: 2) }
+
+      it 'returns the newest two statuses' do
+        expect(subject.next_objects).to eq [statuses[2], statuses[1]]
+      end
+    end
+
+    context 'with cursor set to second newest status' do
+      subject do
+        Fabricate(:fasp_backfill_request, max_count: 2, cursor: statuses[1].id)
+      end
+
+      it 'returns the oldest status' do
+        expect(subject.next_objects).to eq [statuses[0]]
+      end
+    end
+
+    context 'when all statuses are not `indexable`' do
+      subject { Fabricate(:fasp_backfill_request) }
+
+      let(:account) { Fabricate(:account, indexable: false) }
+
+      it 'returns no statuses' do
+        expect(subject.next_objects).to be_empty
+      end
+    end
+  end
+
+  describe '#next_uris' do
+    subject { Fabricate(:fasp_backfill_request) }
+
+    let(:statuses) { Fabricate.times(2, :status) }
+
+    it 'returns uris of the next objects' do
+      uris = statuses.map(&:uri)
+
+      expect(subject.next_uris).to match_array(uris)
+    end
+  end
+
+  describe '#more_objects_available?' do
+    subject { Fabricate(:fasp_backfill_request, max_count: 2) }
+
+    context 'when more objects are available' do
+      before { Fabricate.times(3, :status) }
+
+      it 'returns `true`' do
+        expect(subject.more_objects_available?).to be true
+      end
+    end
+
+    context 'when no more objects are available' do
+      before { Fabricate.times(2, :status) }
+
+      it 'returns `false`' do
+        expect(subject.more_objects_available?).to be false
+      end
+    end
+  end
+
+  describe '#advance!' do
+    subject { Fabricate(:fasp_backfill_request, max_count: 2) }
+
+    context 'when more objects are available' do
+      before { Fabricate.times(3, :status) }
+
+      it 'updates `cursor`' do
+        expect { subject.advance! }.to change(subject, :cursor)
+        expect(subject).to be_persisted
+      end
+    end
+
+    context 'when no more objects are available' do
+      before { Fabricate.times(2, :status) }
+
+      it 'sets `fulfilled` to `true`' do
+        expect { subject.advance! }.to change(subject, :fulfilled)
+          .from(false).to(true)
+        expect(subject).to be_persisted
+      end
+    end
+  end
+end

spec/models/fasp/subscription_spec.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Fasp::Subscription do
+  describe '#threshold=' do
+    subject { described_class.new }
+
+    it 'allows setting all threshold values at once' do
+      subject.threshold = {
+        'timeframe' => 30,
+        'shares' => 5,
+        'likes' => 8,
+        'replies' => 7,
+      }
+
+      expect(subject.threshold_timeframe).to eq 30
+      expect(subject.threshold_shares).to eq 5
+      expect(subject.threshold_likes).to eq 8
+      expect(subject.threshold_replies).to eq 7
+    end
+  end
+
+  describe '#timeframe_start' do
+    subject { described_class.new(threshold_timeframe: 45) }
+
+    it 'returns a Time representing the beginning of the timeframe' do
+      travel_to Time.zone.local(2025, 4, 7, 16, 40) do
+        expect(subject.timeframe_start).to eq Time.zone.local(2025, 4, 7, 15, 55)
+      end
+    end
+  end
+end

spec/requests/api/fasp/data_sharing/v0/backfill_requests_spec.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Api::Fasp::DataSharing::V0::BackfillRequests', feature: :fasp do
+  include ProviderRequestHelper
+
+  describe 'POST /api/fasp/data_sharing/v0/backfill_requests' do
+    let(:provider) { Fabricate(:fasp_provider) }
+
+    context 'with valid parameters' do
+      it 'creates a new backfill request' do
+        params = { category: 'content', maxCount: 10 }
+        headers = request_authentication_headers(provider,
+                                                 url: api_fasp_data_sharing_v0_backfill_requests_url,
+                                                 method: :post,
+                                                 body: params)
+
+        expect do
+          post api_fasp_data_sharing_v0_backfill_requests_path, headers:, params:, as: :json
+        end.to change(Fasp::BackfillRequest, :count).by(1)
+        expect(response).to have_http_status(201)
+      end
+    end
+
+    context 'with invalid parameters' do
+      it 'does not create a backfill request' do
+        params = { category: 'unknown', maxCount: 10 }
+        headers = request_authentication_headers(provider,
+                                                 url: api_fasp_data_sharing_v0_backfill_requests_url,
+                                                 method: :post,
+                                                 body: params)
+
+        expect do
+          post api_fasp_data_sharing_v0_backfill_requests_path, headers:, params:, as: :json
+        end.to_not change(Fasp::BackfillRequest, :count)
+        expect(response).to have_http_status(422)
+      end
+    end
+  end
+end

spec/requests/api/fasp/data_sharing/v0/continuations_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Api::Fasp::DataSharing::V0::Continuations', feature: :fasp do
+  include ProviderRequestHelper
+
+  describe 'POST /api/fasp/data_sharing/v0/backfill_requests/:id/continuations' do
+    let(:backfill_request) { Fabricate(:fasp_backfill_request) }
+    let(:provider) { backfill_request.fasp_provider }
+
+    it 'queues a job to continue the given backfill request' do
+      headers = request_authentication_headers(provider,
+                                               url: api_fasp_data_sharing_v0_backfill_request_continuation_url(backfill_request),
+                                               method: :post)
+
+      post api_fasp_data_sharing_v0_backfill_request_continuation_path(backfill_request), headers:, as: :json
+      expect(response).to have_http_status(204)
+      expect(Fasp::BackfillWorker).to have_enqueued_sidekiq_job(backfill_request.id)
+    end
+  end
+end

spec/requests/api/fasp/data_sharing/v0/event_subscriptions_spec.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Api::Fasp::DataSharing::V0::EventSubscriptions', feature: :fasp do
+  include ProviderRequestHelper
+
+  describe 'POST /api/fasp/data_sharing/v0/event_subscriptions' do
+    let(:provider) { Fabricate(:fasp_provider) }
+
+    context 'with valid parameters' do
+      it 'creates a new subscription' do
+        params = { category: 'content', subscriptionType: 'lifecycle', maxBatchSize: 10 }
+        headers = request_authentication_headers(provider,
+                                                 url: api_fasp_data_sharing_v0_event_subscriptions_url,
+                                                 method: :post,
+                                                 body: params)
+
+        expect do
+          post api_fasp_data_sharing_v0_event_subscriptions_path, headers:, params:, as: :json
+        end.to change(Fasp::Subscription, :count).by(1)
+        expect(response).to have_http_status(201)
+      end
+    end
+
+    context 'with invalid parameters' do
+      it 'does not create a subscription' do
+        params = { category: 'unknown' }
+        headers = request_authentication_headers(provider,
+                                                 url: api_fasp_data_sharing_v0_event_subscriptions_url,
+                                                 method: :post,
+                                                 body: params)
+
+        expect do
+          post api_fasp_data_sharing_v0_event_subscriptions_path, headers:, params:, as: :json
+        end.to_not change(Fasp::Subscription, :count)
+        expect(response).to have_http_status(422)
+      end
+    end
+  end
+
+  describe 'DELETE /api/fasp/data_sharing/v0/event_subscriptions/:id' do
+    let(:subscription) { Fabricate(:fasp_subscription) }
+    let(:provider) { subscription.fasp_provider }
+
+    it 'deletes the subscription' do
+      headers = request_authentication_headers(provider,
+                                               url: api_fasp_data_sharing_v0_event_subscription_url(subscription),
+                                               method: :delete)
+
+      expect do
+        delete api_fasp_data_sharing_v0_event_subscription_path(subscription), headers:, as: :json
+      end.to change(Fasp::Subscription, :count).by(-1)
+      expect(response).to have_http_status(204)
+    end
+  end
+end

spec/workers/fasp/announce_account_lifecycle_event_worker_spec.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Fasp::AnnounceAccountLifecycleEventWorker do
+  include ProviderRequestHelper
+
+  let(:account_uri) { 'https://masto.example.com/accounts/1' }
+  let(:subscription) do
+    Fabricate(:fasp_subscription, category: 'account')
+  end
+  let(:provider) { subscription.fasp_provider }
+  let!(:stubbed_request) do
+    stub_provider_request(provider,
+                          method: :post,
+                          path: '/data_sharing/v0/announcements',
+                          response_body: {
+                            source: {
+                              subscription: {
+                                id: subscription.id.to_s,
+                              },
+                            },
+                            category: 'account',
+                            eventType: 'new',
+                            objectUris: [account_uri],
+                          })
+  end
+
+  it 'sends the account uri to subscribed providers' do
+    described_class.new.perform(account_uri, 'new')
+
+    expect(stubbed_request).to have_been_made
+  end
+end

spec/workers/fasp/announce_content_lifecycle_event_worker_spec.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Fasp::AnnounceContentLifecycleEventWorker do
+  include ProviderRequestHelper
+
+  let(:status_uri) { 'https://masto.example.com/status/1' }
+  let(:subscription) do
+    Fabricate(:fasp_subscription)
+  end
+  let(:provider) { subscription.fasp_provider }
+  let!(:stubbed_request) do
+    stub_provider_request(provider,
+                          method: :post,
+                          path: '/data_sharing/v0/announcements',
+                          response_body: {
+                            source: {
+                              subscription: {
+                                id: subscription.id.to_s,
+                              },
+                            },
+                            category: 'content',
+                            eventType: 'new',
+                            objectUris: [status_uri],
+                          })
+  end
+
+  it 'sends the status uri to subscribed providers' do
+    described_class.new.perform(status_uri, 'new')
+
+    expect(stubbed_request).to have_been_made
+  end
+end

spec/workers/fasp/announce_trend_worker_spec.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Fasp::AnnounceTrendWorker do
+  include ProviderRequestHelper
+
+  let(:status) { Fabricate(:status) }
+  let(:subscription) do
+    Fabricate(:fasp_subscription,
+              category: 'content',
+              subscription_type: 'trends',
+              threshold_timeframe: 15,
+              threshold_likes: 2)
+  end
+  let(:provider) { subscription.fasp_provider }
+  let!(:stubbed_request) do
+    stub_provider_request(provider,
+                          method: :post,
+                          path: '/data_sharing/v0/announcements',
+                          response_body: {
+                            source: {
+                              subscription: {
+                                id: subscription.id.to_s,
+                              },
+                            },
+                            category: 'content',
+                            eventType: 'trending',
+                            objectUris: [status.uri],
+                          })
+  end
+
+  context 'when the configured threshold is met' do
+    before do
+      Fabricate.times(2, :favourite, status:)
+    end
+
+    it 'sends the account uri to subscribed providers' do
+      described_class.new.perform(status.id, 'favourite')
+
+      expect(stubbed_request).to have_been_made
+    end
+  end
+
+  context 'when the configured threshold is not met' do
+    it 'does not notify any provider' do
+      described_class.new.perform(status.id, 'favourite')
+
+      expect(stubbed_request).to_not have_been_made
+    end
+  end
+end

spec/workers/fasp/backfill_worker_spec.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Fasp::BackfillWorker do
+  include ProviderRequestHelper
+
+  let(:backfill_request) { Fabricate(:fasp_backfill_request) }
+  let(:provider) { backfill_request.fasp_provider }
+  let(:status) { Fabricate(:status) }
+  let!(:stubbed_request) do
+    stub_provider_request(provider,
+                          method: :post,
+                          path: '/data_sharing/v0/announcements',
+                          response_body: {
+                            source: {
+                              backfillRequest: {
+                                id: backfill_request.id.to_s,
+                              },
+                            },
+                            category: 'content',
+                            objectUris: [status.uri],
+                            moreObjectsAvailable: false,
+                          })
+  end
+
+  it 'sends status uri to provider that requested backfill' do
+    described_class.new.perform(backfill_request.id)
+
+    expect(stubbed_request).to have_been_made
+  end
+end