Change link previews to keep original URL from the status (#27312)

app/chewy/public_statuses_index.rb

@@ -53,7 +53,7 @@ class PublicStatusesIndex < Chewy::Index
   index_scope ::Status.unscoped
                       .kept
                       .indexable
-                      .includes(:media_attachments, :preloadable_poll, :preview_cards, :tags)
+                      .includes(:media_attachments, :preloadable_poll, :tags, preview_cards_status: :preview_card)
 
   root date_detection: false do
     field(:id, type: 'long')

app/chewy/statuses_index.rb

@@ -50,7 +50,7 @@ class StatusesIndex < Chewy::Index
     },
   }
 
-  index_scope ::Status.unscoped.kept.without_reblogs.includes(:media_attachments, :preview_cards, :local_mentioned, :local_favorited, :local_reblogged, :local_bookmarked, :tags, preloadable_poll: :local_voters), delete_if: ->(status) { status.searchable_by.empty? }
+  index_scope ::Status.unscoped.kept.without_reblogs.includes(:media_attachments, :local_mentioned, :local_favorited, :local_reblogged, :local_bookmarked, :tags, preview_cards_status: :preview_card, preloadable_poll: :local_voters), delete_if: ->(status) { status.searchable_by.empty? }
 
   root date_detection: false do
     field(:id, type: 'long')

app/controllers/api/v1/conversations_controller.rb

@@ -41,10 +41,10 @@ class Api::V1::ConversationsController < Api::BaseController
                          account: :account_stat,
                          last_status: [
                            :media_attachments,
-                           :preview_cards,
                            :status_stat,
                            :tags,
                            {
+                             preview_cards_status: :preview_card,
                              active_mentions: [account: :account_stat],
                              account: :account_stat,
                            },

app/models/admin/status_batch_action.rb

@@ -74,7 +74,7 @@ class Admin::StatusBatchAction
 
     # Can't use a transaction here because UpdateStatusService queues
     # Sidekiq jobs
-    statuses.includes(:media_attachments, :preview_cards).find_each do |status|
+    statuses.includes(:media_attachments, preview_cards_status: :preview_card).find_each do |status|
       next if status.discarded? || !(status.with_media? || status.with_preview_card?)
 
       authorize([:admin, status], :update?)

app/models/concerns/status_search_concern.rb

@@ -40,7 +40,7 @@ module StatusSearchConcern
       properties << 'media' if with_media?
       properties << 'poll' if with_poll?
       properties << 'link' if with_preview_card?
-      properties << 'embed' if preview_cards.any?(&:video?)
+      properties << 'embed' if preview_card&.video?
       properties << 'sensitive' if sensitive?
       properties << 'reply' if reply?
     end

app/models/preview_card.rb

@@ -50,7 +50,9 @@ class PreviewCard < ApplicationRecord
   enum type: { link: 0, photo: 1, video: 2, rich: 3 }
   enum link_type: { unknown: 0, article: 1 }
 
-  has_and_belongs_to_many :statuses
+  has_many :preview_cards_statuses, dependent: :delete_all, inverse_of: :preview_card
+  has_many :statuses, through: :preview_cards_statuses
+
   has_one :trend, class_name: 'PreviewCardTrend', inverse_of: :preview_card, dependent: :destroy
 
   has_attached_file :image, processors: [:thumbnail, :blurhash_transcoder], styles: ->(f) { image_styles(f) }, convert_options: { all: '-quality 90 +profile "!icc,*" +set date:modify +set date:create +set date:timestamp' }, validate_media_type: false
@@ -64,6 +66,9 @@ class PreviewCard < ApplicationRecord
 
   before_save :extract_dimensions, if: :link?
 
+  # This can be set by the status when retrieving the preview card using the join model
+  attr_accessor :original_url
+
   def appropriate_for_trends?
     link? && article? && title.present? && description.present? && image.present? && provider_name.present?
   end

app/models/preview_cards_status.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: preview_cards_statuses
+#
+#  preview_card_id :bigint(8)        not null
+#  status_id       :bigint(8)        not null
+#  url             :string
+#
+class PreviewCardsStatus < ApplicationRecord
+  # Composite primary keys are not properly supported in Rails. However,
+  # we shouldn't need this anyway...
+  self.primary_key = nil
+
+  belongs_to :preview_card
+  belongs_to :status
+end

app/models/status.rb

@@ -79,8 +79,8 @@ class Status < ApplicationRecord
   has_many :local_bookmarked, -> { merge(Account.local) }, through: :bookmarks, source: :account
 
   has_and_belongs_to_many :tags
-  has_and_belongs_to_many :preview_cards
 
+  has_one :preview_cards_status, inverse_of: :status # Because of a composite primary key, the dependent option cannot be used
   has_one :notification, as: :activity, dependent: :destroy
   has_one :status_stat, inverse_of: :status
   has_one :poll, inverse_of: :status, dependent: :destroy
@@ -142,24 +142,25 @@ class Status < ApplicationRecord
   # The `prepend: true` option below ensures this runs before
   # the `dependent: destroy` callbacks remove relevant records
   before_destroy :unlink_from_conversations!, prepend: true
+  before_destroy :reset_preview_card!
 
   cache_associated :application,
                    :media_attachments,
                    :conversation,
                    :status_stat,
                    :tags,
-                   :preview_cards,
                    :preloadable_poll,
+                   preview_cards_status: [:preview_card],
                    account: [:account_stat, user: :role],
                    active_mentions: { account: :account_stat },
                    reblog: [
                      :application,
                      :tags,
-                     :preview_cards,
                      :media_attachments,
                      :conversation,
                      :status_stat,
                      :preloadable_poll,
+                     preview_cards_status: [:preview_card],
                      account: [:account_stat, user: :role],
                      active_mentions: { account: :account_stat },
                    ],
@@ -226,7 +227,11 @@ class Status < ApplicationRecord
   end
 
   def preview_card
-    preview_cards.first
+    preview_cards_status&.preview_card&.tap { |x| x.original_url = preview_cards_status.url }
+  end
+
+  def reset_preview_card!
+    PreviewCardsStatus.where(status_id: id).delete_all
   end
 
   def hidden?
@@ -244,7 +249,7 @@ class Status < ApplicationRecord
   end
 
   def with_preview_card?
-    preview_cards.any?
+    preview_cards_status.present?
   end
 
   def with_poll?

app/models/trends/links.rb

@@ -54,9 +54,7 @@ class Trends::Links < Trends::Base
                   !(original_status.account.silenced? || status.account.silenced?) &&
                   !(original_status.spoiler_text? || original_status.sensitive?)
 
-    original_status.preview_cards.each do |preview_card|
-      add(preview_card, status.account_id, at_time) if preview_card.appropriate_for_trends?
-    end
+    add(original_status.preview_card, status.account_id, at_time) if original_status.preview_card&.appropriate_for_trends?
   end
 
   def add(preview_card, account_id, at_time = Time.now.utc)

app/serializers/rest/preview_card_serializer.rb

@@ -8,6 +8,10 @@ class REST::PreviewCardSerializer < ActiveModel::Serializer
              :provider_url, :html, :width, :height,
              :image, :image_description, :embed_url, :blurhash, :published_at
 
+  def url
+    object.original_url.presence || object.url
+  end
+
   def image
     object.image? ? full_asset_url(object.image.url(:original)) : nil
   end

app/services/activitypub/process_status_update_service.rb

@@ -280,7 +280,7 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
   end
 
   def reset_preview_card!
-    @status.preview_cards.clear
+    @status.reset_preview_card!
     LinkCrawlWorker.perform_in(rand(1..59).seconds, @status.id)
   end
 

app/services/fetch_link_card_service.rb

@@ -19,7 +19,7 @@ class FetchLinkCardService < BaseService
     @status       = status
     @original_url = parse_urls
 
-    return if @original_url.nil? || @status.preview_cards.any?
+    return if @original_url.nil? || @status.with_preview_card?
 
     @url = @original_url.to_s
 
@@ -62,9 +62,9 @@ class FetchLinkCardService < BaseService
 
   def attach_card
     with_redis_lock("attach_card:#{@status.id}") do
-      return if @status.preview_cards.any?
+      return if @status.with_preview_card?
 
-      @status.preview_cards << @card
+      PreviewCardsStatus.create(status: @status, preview_card: @card, url: @original_url)
       Rails.cache.delete(@status)
       Trends.links.register(@status)
     end

app/services/update_status_service.rb

@@ -123,7 +123,7 @@ class UpdateStatusService < BaseService
   def reset_preview_card!
     return unless @status.text_previously_changed?
 
-    @status.preview_cards.clear
+    @status.reset_preview_card!
     LinkCrawlWorker.perform_async(@status.id)
   end
 

db/migrate/20231006183200_add_url_to_preview_cards_statuses.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddURLToPreviewCardsStatuses < ActiveRecord::Migration[7.0]
+  def change
+    add_column :preview_cards_statuses, :url, :string
+  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_06_183200) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -811,6 +811,7 @@ ActiveRecord::Schema[7.0].define(version: 2023_09_07_150100) do
   create_table "preview_cards_statuses", primary_key: ["status_id", "preview_card_id"], force: :cascade do |t|
     t.bigint "preview_card_id", null: false
     t.bigint "status_id", null: false
+    t.string "url"
   end
 
   create_table "relays", force: :cascade do |t|

lib/tasks/tests.rake

@@ -69,7 +69,7 @@ namespace :tests do
         exit(1)
       end
 
-      unless Status.find(12).preview_cards.pluck(:url) == ['https://joinmastodon.org/']
+      unless PreviewCard.where(id: PreviewCardsStatus.where(status_id: 12).select(:preview_card_id)).pluck(:url) == ['https://joinmastodon.org/']
         puts 'Preview cards not deduplicated as expected'
         exit(1)
       end

spec/helpers/media_component_helper_spec.rb

@@ -49,10 +49,12 @@ describe MediaComponentHelper do
   end
 
   describe 'render_card_component' do
-    let(:status) { Fabricate(:status, preview_cards: [Fabricate(:preview_card)]) }
+    let(:status) { Fabricate(:status) }
     let(:result) { helper.render_card_component(status) }
 
     before do
+      PreviewCardsStatus.create(status: status, preview_card: Fabricate(:preview_card))
+
       without_partial_double_verification do
         allow(helper).to receive(:current_account).and_return(status.account)
       end

spec/services/fetch_link_card_service_spec.rb

@@ -120,7 +120,7 @@ RSpec.describe FetchLinkCardService, type: :service do
       let(:status) { Fabricate(:status, text: 'Check out http://example.com/sjis') }
 
       it 'decodes the HTML' do
-        expect(status.preview_cards.first.title).to eq('SJISのページ')
+        expect(status.preview_card.title).to eq('SJISのページ')
       end
     end
 
@@ -128,7 +128,7 @@ RSpec.describe FetchLinkCardService, type: :service do
       let(:status) { Fabricate(:status, text: 'Check out http://example.com/sjis_with_wrong_charset') }
 
       it 'decodes the HTML despite the wrong charset header' do
-        expect(status.preview_cards.first.title).to eq('SJISのページ')
+        expect(status.preview_card.title).to eq('SJISのページ')
       end
     end
 
@@ -136,7 +136,7 @@ RSpec.describe FetchLinkCardService, type: :service do
       let(:status) { Fabricate(:status, text: 'Check out http://example.com/koi8-r') }
 
       it 'decodes the HTML' do
-        expect(status.preview_cards.first.title).to eq('Московя начинаетъ только въ XVI ст. привлекать внимане иностранцевъ.')
+        expect(status.preview_card.title).to eq('Московя начинаетъ только въ XVI ст. привлекать внимане иностранцевъ.')
       end
     end
 
@@ -144,7 +144,7 @@ RSpec.describe FetchLinkCardService, type: :service do
       let(:status) { Fabricate(:status, text: 'Check out http://example.com/windows-1251') }
 
       it 'decodes the HTML' do
-        expect(status.preview_cards.first.title).to eq('сэмпл текст')
+        expect(status.preview_card.title).to eq('сэмпл текст')
       end
     end
 

spec/services/update_status_service_spec.rb

@@ -23,11 +23,11 @@ RSpec.describe UpdateStatusService, type: :service do
   end
 
   context 'when text changes' do
-    let!(:status) { Fabricate(:status, text: 'Foo') }
+    let(:status) { Fabricate(:status, text: 'Foo') }
     let(:preview_card) { Fabricate(:preview_card) }
 
     before do
-      status.preview_cards << preview_card
+      PreviewCardsStatus.create(status: status, preview_card: preview_card)
       subject.call(status, status.account_id, text: 'Bar')
     end
 
@@ -45,11 +45,11 @@ RSpec.describe UpdateStatusService, type: :service do
   end
 
   context 'when content warning changes' do
-    let!(:status) { Fabricate(:status, text: 'Foo', spoiler_text: '') }
+    let(:status) { Fabricate(:status, text: 'Foo', spoiler_text: '') }
     let(:preview_card) { Fabricate(:preview_card) }
 
     before do
-      status.preview_cards << preview_card
+      PreviewCardsStatus.create(status: status, preview_card: preview_card)
       subject.call(status, status.account_id, text: 'Foo', spoiler_text: 'Bar')
     end