[WiP] Add notification type for relationship severance events

app/controllers/severed_relationships_controller.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+class SeveredRelationshipsController < ApplicationController
+  layout 'admin'
+
+  before_action :authenticate_user!
+  before_action :set_body_classes
+  before_action :set_cache_headers
+
+  before_action :set_event, only: [:following, :followers]
+
+  def index
+    @events = RelationshipSeveranceEvent.about_account(current_account)
+  end
+
+  def following
+    respond_to do |format|
+      format.csv { send_data following_data, filename: 'following-TODO.csv' }
+    end
+  end
+
+  def followers
+    respond_to do |format|
+      format.csv { send_data followers_data, filename: 'followers-TODO.csv' }
+    end
+  end
+
+  private
+
+  def set_event
+    @event = RelationshipSeveranceEvent.find(params[:id])
+  end
+
+  def following_data
+    CSV.generate(headers: ['Account address', 'Show boosts', 'Notify on new posts', 'Languages'], write_headers: true) do |csv|
+      @event.severed_relationships.where(account: current_account).includes(:target_account).reorder(id: :desc).each do |follow|
+        csv << [acct(follow.target_account), follow.show_reblogs, follow.notify, follow.languages&.join(', ')]
+      end
+    end
+  end
+
+  def followers_data
+    CSV.generate(headers: ['Account address'], write_headers: true) do |csv|
+      @event.severed_relationships.where(target_account: current_account).includes(:account).reorder(id: :desc).each do |follow|
+        csv << [acct(follow.account)]
+      end
+    end
+  end
+
+  def acct(account)
+    account.local? ? account.local_username_and_domain : account.acct
+  end
+
+  def set_body_classes
+    @body_classes = 'admin'
+  end
+
+  def set_cache_headers
+    response.cache_control.replace(private: true, no_store: true)
+  end
+end

app/models/notification.rb

@@ -37,6 +37,7 @@ class Notification < ApplicationRecord
     favourite
     poll
     update
+    relationships_severed
     admin.sign_up
     admin.report
   ).freeze
@@ -63,6 +64,7 @@ class Notification < ApplicationRecord
     belongs_to :favourite, inverse_of: :notification
     belongs_to :poll, inverse_of: false
     belongs_to :report, inverse_of: false
+    belongs_to :relationship_severance_event, inverse_of: false
   end
 
   validates :type, inclusion: { in: TYPES }
@@ -156,6 +158,11 @@ class Notification < ApplicationRecord
       self.from_account_id = activity&.status&.account_id
     when 'Account'
       self.from_account_id = activity&.id
+    when 'RelationshipSeveranceEvent'
+      # These do not really have an originating account, but this is mandatory
+      # in the data model, and the recipient's account will by definition
+      # always exist
+      self.from_account_id = account_id
     end
   end
 end

app/models/relationship_severance_event.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: relationship_severance_events
+#
+#  id         :bigint(8)        not null, primary key
+#  type       :integer          not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+class RelationshipSeveranceEvent < ApplicationRecord
+  self.inheritance_column = nil
+
+  has_many :severed_relationships, inverse_of: :relationship_severance_event, dependent: :delete_all
+
+  enum type: {
+    domain_block: 0,
+    user_domain_block: 1,
+  }
+
+  scope :about_account, ->(account) { where(id: SeveredRelationship.about_account(account).select(:relationship_severance_event_id)) }
+
+  def import_from_follows!(follows)
+    SeveredRelationship.insert_all( # rubocop:disable Rails/SkipsModelValidations
+      follows.pluck(:account_id, :target_account_id, :show_reblogs, :notify, :languages).map do |account_id, target_account_id, show_reblogs, notify, languages|
+        {
+          account_id: account_id,
+          target_account_id: target_account_id,
+          show_reblogs: show_reblogs,
+          notify: notify,
+          languages: languages,
+          relationship_severance_event_id: id,
+        }
+      end
+    )
+  end
+end

app/models/severed_relationship.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: severed_relationships
+#
+#  id                              :bigint(8)        not null, primary key
+#  relationship_severance_event_id :bigint(8)        not null
+#  account_id                      :bigint(8)        not null
+#  target_account_id               :bigint(8)        not null
+#  show_reblogs                    :boolean
+#  notify                          :boolean
+#  languages                       :string           is an Array
+#  created_at                      :datetime         not null
+#  updated_at                      :datetime         not null
+#
+class SeveredRelationship < ApplicationRecord
+  belongs_to :relationship_severance_event
+  belongs_to :account
+  belongs_to :target_account, class_name: 'Account'
+
+  scope :about_account, ->(account) { where(account: account).or(where(target_account: account)) }
+end

app/serializers/rest/notification_serializer.rb

@@ -6,6 +6,7 @@ class REST::NotificationSerializer < ActiveModel::Serializer
   belongs_to :from_account, key: :account, serializer: REST::AccountSerializer
   belongs_to :target_status, key: :status, if: :status_type?, serializer: REST::StatusSerializer
   belongs_to :report, if: :report_type?, serializer: REST::ReportSerializer
+  belongs_to :relationship_severance_event, key: :event, if: :relationship_severance_event?, serializer: REST::RelationshipSeveranceEventSerializer
 
   def id
     object.id.to_s
@@ -18,4 +19,8 @@ class REST::NotificationSerializer < ActiveModel::Serializer
   def report_type?
     object.type == :'admin.report'
   end
+
+  def relationship_severance_event?
+    object.type == :relationship_severance_event
+  end
 end

app/serializers/rest/relationship_severance_event_serializer.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class REST::RelationshipSeveranceEventSerializer < ActiveModel::Serializer
+  attributes :id, :type, :domain, :created_at
+
+  def id
+    object.id.to_s
+  end
+end

app/services/after_block_domain_from_account_service.rb

@@ -9,6 +9,7 @@ class AfterBlockDomainFromAccountService < BaseService
   def call(account, domain)
     @account = account
     @domain  = domain
+    @domain_block_event = nil
 
     clear_notifications!
     remove_follows!
@@ -19,8 +20,9 @@ class AfterBlockDomainFromAccountService < BaseService
   private
 
   def remove_follows!
-    @account.active_relationships.where(target_account: Account.where(domain: @domain)).includes(:target_account).reorder(nil).find_each do |follow|
-      UnfollowService.new.call(@account, follow.target_account)
+    @account.active_relationships.where(target_account: Account.where(domain: @domain)).includes(:target_account).reorder(nil).in_batches do |follows|
+      domain_block_event.import_from_follows!(follows)
+      follows.each { |follow| UnfollowService.new.call(@account, follow.target_account) }
     end
   end
 
@@ -29,8 +31,9 @@ class AfterBlockDomainFromAccountService < BaseService
   end
 
   def reject_existing_followers!
-    @account.passive_relationships.where(account: Account.where(domain: @domain)).includes(:account).reorder(nil).find_each do |follow|
-      reject_follow!(follow)
+    @account.passive_relationships.where(account: Account.where(domain: @domain)).includes(:account).reorder(nil).in_batches do |follows|
+      domain_block_event.import_from_follows!(follows)
+      follows.each { |follow| reject_follow!(follow) }
     end
   end
 
@@ -47,4 +50,8 @@ class AfterBlockDomainFromAccountService < BaseService
 
     ActivityPub::DeliveryWorker.perform_async(Oj.dump(serialize_payload(follow, ActivityPub::RejectFollowSerializer)), @account.id, follow.account.inbox_url)
   end
+
+  def domain_block_event
+    @domain_block_event ||= RelationshipSeveranceEvent.create!(type: :user_domain_block, domain: @domain)
+  end
 end

app/services/block_domain_service.rb

@@ -5,6 +5,7 @@ class BlockDomainService < BaseService
 
   def call(domain_block, update = false)
     @domain_block = domain_block
+    @domain_block_event = nil
     process_domain_block!
     process_retroactive_updates! if update
   end
@@ -37,7 +38,7 @@ class BlockDomainService < BaseService
     blocked_domain_accounts.without_suspended.in_batches.update_all(suspended_at: @domain_block.created_at, suspension_origin: :local)
 
     blocked_domain_accounts.where(suspended_at: @domain_block.created_at).reorder(nil).find_each do |account|
-      DeleteAccountService.new.call(account, reserve_username: true, suspended_at: @domain_block.created_at)
+      DeleteAccountService.new.call(account, reserve_username: true, suspended_at: @domain_block.created_at, relationship_severance_event: domain_block_event)
     end
   end
 
@@ -45,6 +46,10 @@ class BlockDomainService < BaseService
     domain_block.domain
   end
 
+  def domain_block_event
+    @domain_block_event ||= RelationshipSeveranceEvent.create!(type: :domain_block, domain: blocked_domain)
+  end
+
   def blocked_domain_accounts
     Account.by_domain_and_subdomains(blocked_domain)
   end

app/services/delete_account_service.rb

@@ -72,6 +72,7 @@ class DeleteAccountService < BaseService
   # @option [Boolean] :skip_side_effects Side effects are ActivityPub and streaming API payloads
   # @option [Boolean] :skip_activitypub Skip sending ActivityPub payloads. Implied by :skip_side_effects
   # @option [Time]    :suspended_at Only applicable when :reserve_username is true
+  # @option [RelationshipSeveranceEvent] :relationship_severance_event Event used to record severed relationships not initiated by the user
   def call(account, **options)
     @account = account
     @options = { reserve_username: true, reserve_email: true }.merge(options)
@@ -84,6 +85,7 @@ class DeleteAccountService < BaseService
 
     @options[:skip_activitypub] = true if @options[:skip_side_effects]
 
+    record_severed_relationships!
     distribute_activities!
     purge_content!
     fulfill_deletion_request!
@@ -266,6 +268,18 @@ class DeleteAccountService < BaseService
     end
   end
 
+  def record_severed_relationships!
+    return if relationship_severance_event.nil?
+
+    Follow.where(target_account: @account).in_batches do |follows|
+      relationship_severance_event.import_from_follows!(follows)
+    end
+
+    Follow.where(account: @account).in_batches do |follows|
+      relationship_severance_event.import_from_follows!(follows)
+    end
+  end
+
   def delete_actor_json
     @delete_actor_json ||= Oj.dump(serialize_payload(@account, ActivityPub::DeleteActorSerializer, signer: @account, always_sign: true))
   end
@@ -305,4 +319,8 @@ class DeleteAccountService < BaseService
   def skip_activitypub?
     @options[:skip_activitypub]
   end
+
+  def relationship_severance_event
+    @options[:relationship_severance_event]
+  end
 end

app/services/notify_service.rb

@@ -109,7 +109,7 @@ class NotifyService < BaseService
 
   def blocked?
     blocked   = @recipient.suspended?
-    blocked ||= from_self? && @notification.type != :poll
+    blocked ||= from_self? && @notification.type != :poll && @notification.type != :relationships_severed
 
     return blocked if message? && from_staff?
 

app/views/severed_relationships/index.html.haml

@@ -0,0 +1,31 @@
+- content_for :page_title do
+  = t('settings.severed_relationships')
+
+%p.muted-hint= t('severed_relationships.preamble')
+
+- unless @events.empty?
+  .table-wrapper
+    %table.table
+      %thead
+        %tr
+          %th= t('exports.archive_takeout.date')
+          %th= t('severed_relationships.type')
+          %th= t('severed_relationships.lost_follows')
+          %th= t('severed_relationships.lost_followers')
+      %tbody
+        - @events.each do |event|
+          %tr
+            %td= l event.created_at
+            %td= t("severed_relationships.event_type.#{event.type}")
+            %td
+              - count = event.severed_relationships.where(account: current_account).count
+              - if count.zero?
+                = t('generic.none')
+              - else
+                = table_link_to 'download', t('severed_relationships.download', count: count), following_severed_relationship_path(event, format: :csv)
+            %td
+              - count = event.severed_relationships.where(target_account: current_account).count
+              - if count.zero?
+                = t('generic.none')
+              - else
+                = table_link_to 'download', t('severed_relationships.download', count: count), followers_severed_relationship_path(event, format: :csv)

config/locales/en.yml

@@ -1648,10 +1648,19 @@ en:
     preferences: Preferences
     profile: Public profile
     relationships: Follows and followers
+    severed_relationships: Severed relationships
     statuses_cleanup: Automated post deletion
     strikes: Moderation strikes
     two_factor_authentication: Two-factor Auth
     webauthn_authentication: Security keys
+  severed_relationships:
+    download: Download (%{count})
+    event_type:
+      domain_block: Server suspension
+    lost_followers: Lost followers
+    lost_follows: Lost follows
+    preamble: You may lose follows and followers when you block a domain or when your moderators decide to suspend a remote server. When that happens, you will be able to download lists of severed relationships, to be inspected and possibly imported on another server.
+    type: Event
   statuses:
     attached:
       audio:

config/navigation.rb

@@ -16,7 +16,11 @@ SimpleNavigation::Configuration.run do |navigation|
       s.item :other, safe_join([fa_icon('cog fw'), t('preferences.other')]), settings_preferences_other_path
     end
 
-    n.item :relationships, safe_join([fa_icon('users fw'), t('settings.relationships')]), relationships_path, if: -> { current_user.functional? && !self_destruct }
+    n.item :relationships, safe_join([fa_icon('users fw'), t('settings.relationships')]), relationships_path, if: -> { current_user.functional? && !self_destruct } do |s|
+      s.item :current, safe_join([fa_icon('users fw'), t('settings.relationships')]), relationships_path
+      s.item :severed_relationships, safe_join([fa_icon('unlink fw'), t('settings.severed_relationships')]), severed_relationships_path
+    end
+
     n.item :filters, safe_join([fa_icon('filter fw'), t('filters.index.title')]), filters_path, highlights_on: %r{/filters}, if: -> { current_user.functional? && !self_destruct }
     n.item :statuses_cleanup, safe_join([fa_icon('history fw'), t('settings.statuses_cleanup')]), statuses_cleanup_path, if: -> { current_user.functional_or_moved? && !self_destruct }
 

config/routes.rb

@@ -161,6 +161,14 @@ Rails.application.routes.draw do
   end
 
   resource :relationships, only: [:show, :update]
+  resources :severed_relationships, only: [:index] do
+    member do
+      constraints(format: :csv) do
+        get :followers
+        get :following
+      end
+    end
+  end
   resource :statuses_cleanup, controller: :statuses_cleanup, only: [:show, :update]
 
   get '/media_proxy/:id/(*any)', to: 'media_proxy#show', as: :media_proxy, format: false

db/migrate/20231023100644_create_relationship_severance_events.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+class CreateRelationshipSeveranceEvents < ActiveRecord::Migration[7.0]
+  def change
+    create_table :relationship_severance_events do |t|
+      t.integer :type, null: false
+      t.string :domain
+
+      t.timestamps
+    end
+  end
+end

db/migrate/20231023105620_create_severed_relationships.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class CreateSeveredRelationships < ActiveRecord::Migration[7.0]
+  def change
+    create_table :severed_relationships do |t|
+      t.references :relationship_severance_event, null: false, foreign_key: { on_delete: :cascade }
+      t.references :account, null: false, foreign_key: { on_delete: :cascade }
+      t.references :target_account, null: false, foreign_key: { to_table: :accounts, on_delete: :cascade }
+
+      t.boolean :show_reblogs
+      t.boolean :notify
+      t.string :languages, array: true
+
+      t.timestamps
+
+      t.index [:relationship_severance_event_id, :account_id, :target_account_id], name: 'index_severed_relationships_on_event_account_and_target_account', unique: true
+      t.index [:account_id, :relationship_severance_event_id], name: 'index_severed_relationships_on_account_and_event'
+      t.index [:target_account_id, :relationship_severance_event_id], name: 'index_severed_relationships_on_target_account_and_event'
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_09_07_150100) do
+ActiveRecord::Schema[7.0].define(version: 2023_10_23_105620) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -813,6 +813,13 @@ ActiveRecord::Schema[7.0].define(version: 2023_09_07_150100) do
     t.bigint "status_id", null: false
   end
 
+  create_table "relationship_severance_events", force: :cascade do |t|
+    t.integer "type", null: false
+    t.string "domain"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
   create_table "relays", force: :cascade do |t|
     t.string "inbox_url", default: "", null: false
     t.string "follow_activity_id"
@@ -891,6 +898,23 @@ ActiveRecord::Schema[7.0].define(version: 2023_09_07_150100) do
     t.index ["thing_type", "thing_id", "var"], name: "index_settings_on_thing_type_and_thing_id_and_var", unique: true
   end
 
+  create_table "severed_relationships", force: :cascade do |t|
+    t.bigint "relationship_severance_event_id", null: false
+    t.bigint "account_id", null: false
+    t.bigint "target_account_id", null: false
+    t.boolean "show_reblogs"
+    t.boolean "notify"
+    t.string "languages", array: true
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id", "relationship_severance_event_id"], name: "index_severed_relationships_on_account_and_event"
+    t.index ["account_id"], name: "index_severed_relationships_on_account_id"
+    t.index ["relationship_severance_event_id", "account_id", "target_account_id"], name: "index_severed_relationships_on_event_account_and_target_account", unique: true
+    t.index ["relationship_severance_event_id"], name: "index_severed_relationships_on_relationship_severance_event_id"
+    t.index ["target_account_id", "relationship_severance_event_id"], name: "index_severed_relationships_on_target_account_and_event"
+    t.index ["target_account_id"], name: "index_severed_relationships_on_target_account_id"
+  end
+
   create_table "site_uploads", force: :cascade do |t|
     t.string "var", default: "", null: false
     t.string "file_file_name"
@@ -1252,6 +1276,9 @@ ActiveRecord::Schema[7.0].define(version: 2023_09_07_150100) do
   add_foreign_key "scheduled_statuses", "accounts", on_delete: :cascade
   add_foreign_key "session_activations", "oauth_access_tokens", column: "access_token_id", name: "fk_957e5bda89", on_delete: :cascade
   add_foreign_key "session_activations", "users", name: "fk_e5fda67334", on_delete: :cascade
+  add_foreign_key "severed_relationships", "accounts", column: "target_account_id", on_delete: :cascade
+  add_foreign_key "severed_relationships", "accounts", on_delete: :cascade
+  add_foreign_key "severed_relationships", "relationship_severance_events", on_delete: :cascade
   add_foreign_key "status_edits", "accounts", on_delete: :nullify
   add_foreign_key "status_edits", "statuses", on_delete: :cascade
   add_foreign_key "status_pins", "accounts", name: "fk_d4cb435b62", on_delete: :cascade