Change algorithm of follow recommendations (#28314)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

.github/renovate.json5

@@ -102,9 +102,12 @@
     {
       // Group actions/*-artifact in the same PR
       matchManagers: ['github-actions'],
-      matchPackageNames: ['actions/download-artifact', 'actions/upload-artifact'],
+      matchPackageNames: [
+        'actions/download-artifact',
+        'actions/upload-artifact',
+      ],
       matchUpdateTypes: ['major'],
-      groupName: 'artifact actions (major)'
+      groupName: 'artifact actions (major)',
     },
     {
       // Update @types/* packages every week, with one grouped PR

app/controllers/admin/follow_recommendations_controller.rb

@@ -8,7 +8,7 @@ module Admin
       authorize :follow_recommendation, :show?
 
       @form     = Form::AccountBatch.new
-      @accounts = filtered_follow_recommendations
+      @accounts = filtered_follow_recommendations.page(params[:page])
     end
 
     def update

app/controllers/api/v1/suggestions_controller.rb

@@ -3,22 +3,23 @@
 class Api::V1::SuggestionsController < Api::BaseController
   include Authorization
 
-  before_action -> { doorkeeper_authorize! :read }
+  before_action -> { doorkeeper_authorize! :read, :'read:accounts' }, only: :index
+  before_action -> { doorkeeper_authorize! :write, :'write:accounts' }, except: :index
   before_action :require_user!
+  before_action :set_suggestions
 
   def index
-    suggestions = suggestions_source.get(current_account, limit: limit_param(DEFAULT_ACCOUNTS_LIMIT))
+    render json: @suggestions.get(limit_param(DEFAULT_ACCOUNTS_LIMIT), params[:offset].to_i).map(&:account), each_serializer: REST::AccountSerializer
-    render json: suggestions.map(&:account), each_serializer: REST::AccountSerializer
   end
 
   def destroy
-    suggestions_source.remove(current_account, params[:id])
+    @suggestions.remove(params[:id])
     render_empty
   end
 
   private
 
-  def suggestions_source
+  def set_suggestions
-    AccountSuggestions::PastInteractionsSource.new
+    @suggestions = AccountSuggestions.new(current_account)
   end
 end

app/controllers/api/v2/suggestions_controller.rb

@@ -3,17 +3,23 @@
 class Api::V2::SuggestionsController < Api::BaseController
   include Authorization
 
-  before_action -> { doorkeeper_authorize! :read }
+  before_action -> { doorkeeper_authorize! :read, :'read:accounts' }, only: :index
+  before_action -> { doorkeeper_authorize! :write, :'write:accounts' }, except: :index
   before_action :require_user!
   before_action :set_suggestions
 
   def index
-    render json: @suggestions, each_serializer: REST::SuggestionSerializer
+    render json: @suggestions.get(limit_param(DEFAULT_ACCOUNTS_LIMIT), params[:offset].to_i), each_serializer: REST::SuggestionSerializer
+  end
+
+  def destroy
+    @suggestions.remove(params[:id])
+    render_empty
   end
 
   private
 
   def set_suggestions
-    @suggestions = AccountSuggestions.get(current_account, limit_param(DEFAULT_ACCOUNTS_LIMIT))
+    @suggestions = AccountSuggestions.new(current_account)
   end
 end

app/lib/potential_friendship_tracker.rb

@@ -1,31 +0,0 @@
-# frozen_string_literal: true
-
-class PotentialFriendshipTracker
-  EXPIRE_AFTER = 90.days.seconds
-  MAX_ITEMS    = 80
-
-  WEIGHTS = {
-    reply: 1,
-    favourite: 10,
-    reblog: 20,
-  }.freeze
-
-  class << self
-    include Redisable
-
-    def record(account_id, target_account_id, action)
-      return if account_id == target_account_id
-
-      key    = "interactions:#{account_id}"
-      weight = WEIGHTS[action]
-
-      redis.zincrby(key, weight, target_account_id)
-      redis.zremrangebyrank(key, 0, -MAX_ITEMS)
-      redis.expire(key, EXPIRE_AFTER)
-    end
-
-    def remove(account_id, target_account_id)
-      redis.zrem("interactions:#{account_id}", target_account_id)
-    end
-  end
-end

app/models/account_domain_block.rb

@@ -19,6 +19,7 @@ class AccountDomainBlock < ApplicationRecord
   validates :domain, presence: true, uniqueness: { scope: :account_id }, domain: true
 
   after_commit :invalidate_domain_blocking_cache
+  after_commit :invalidate_follow_recommendations_cache
 
   private
 
@@ -26,4 +27,8 @@ class AccountDomainBlock < ApplicationRecord
     Rails.cache.delete("exclude_domains_for:#{account_id}")
     Rails.cache.delete(['exclude_domains', account_id, domain])
   end
+
+  def invalidate_follow_recommendations_cache
+    Rails.cache.delete("follow_recommendations/#{account_id}")
+  end
 end

app/models/account_suggestions.rb

@@ -1,28 +1,48 @@
 # frozen_string_literal: true
 
 class AccountSuggestions
+  include DatabaseHelper
+
   SOURCES = [
     AccountSuggestions::SettingSource,
-    AccountSuggestions::PastInteractionsSource,
+    AccountSuggestions::FriendsOfFriendsSource,
+    AccountSuggestions::SimilarProfilesSource,
     AccountSuggestions::GlobalSource,
   ].freeze
 
-  def self.get(account, limit)
+  BATCH_SIZE = 40
-    SOURCES.each_with_object([]) do |source_class, suggestions|
+
-      source_suggestions = source_class.new.get(
+  def initialize(account)
-        account,
+    @account = account
-        skip_account_ids: suggestions.map(&:account_id),
+  end
-        limit: limit - suggestions.size
+
+  def get(limit, offset = 0)
+    with_read_replica do
+      account_ids_with_sources = Rails.cache.fetch("follow_recommendations/#{@account.id}", expires_in: 15.minutes) do
+        SOURCES.flat_map { |klass| klass.new.get(@account, limit: BATCH_SIZE) }.each_with_object({}) do |(account_id, source), h|
+          (h[account_id] ||= []).concat(Array(source).map(&:to_sym))
+        end.to_a.shuffle
+      end
+
+      # The sources deliver accounts that haven't yet been followed, are not blocked,
+      # and so on. Since we reset the cache on follows, blocks, and so on, we don't need
+      # a complicated query on this end.
+
+      account_ids  = account_ids_with_sources[offset, limit]
+      accounts_map = Account.where(id: account_ids.map(&:first)).includes(:account_stat).index_by(&:id)
+
+      account_ids.filter_map do |(account_id, source)|
+        next unless accounts_map.key?(account_id)
+
+        AccountSuggestions::Suggestion.new(
+          account: accounts_map[account_id],
+          source: source
         )
-
+      end
-      suggestions.concat(source_suggestions)
     end
   end
 
-  def self.remove(account, target_account_id)
+  def remove(target_account_id)
-    SOURCES.each do |source_class|
+    FollowRecommendationMute.create(account_id: @account.id, target_account_id: target_account_id)
-      source = source_class.new
-      source.remove(account, target_account_id)
-    end
   end
 end

app/models/account_suggestions/friends_of_friends_source.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+class AccountSuggestions::FriendsOfFriendsSource < AccountSuggestions::Source
+  def get(account, limit: 10)
+    Account.find_by_sql([<<~SQL.squish, { id: account.id, limit: limit }]).map { |row| [row.id, key] }
+      WITH first_degree AS (
+          SELECT target_account_id
+          FROM follows
+          JOIN accounts AS target_accounts ON follows.target_account_id = target_accounts.id
+          WHERE account_id = :id
+            AND NOT target_accounts.hide_collections
+      )
+      SELECT accounts.id, COUNT(*) AS frequency
+      FROM accounts
+      JOIN follows ON follows.target_account_id = accounts.id
+      JOIN account_stats ON account_stats.account_id = accounts.id
+      LEFT OUTER JOIN follow_recommendation_mutes ON follow_recommendation_mutes.target_account_id = accounts.id AND follow_recommendation_mutes.account_id = :id
+      WHERE follows.account_id IN (SELECT * FROM first_degree)
+        AND follows.target_account_id NOT IN (SELECT * FROM first_degree)
+        AND follows.target_account_id <> :id
+        AND accounts.discoverable
+        AND accounts.suspended_at IS NULL
+        AND accounts.silenced_at IS NULL
+        AND accounts.moved_to_account_id IS NULL
+        AND follow_recommendation_mutes.target_account_id IS NULL
+      GROUP BY accounts.id, account_stats.id
+      ORDER BY frequency DESC, account_stats.followers_count ASC
+      LIMIT :limit
+    SQL
+  end
+
+  private
+
+  def key
+    :friends_of_friends
+  end
+end

app/models/account_suggestions/global_source.rb

@@ -1,39 +1,13 @@
 # frozen_string_literal: true
 
 class AccountSuggestions::GlobalSource < AccountSuggestions::Source
-  include Redisable
+  def get(account, limit: 10)
-
+    FollowRecommendation.localized(content_locale).joins(:account).merge(base_account_scope(account)).order(rank: :desc).limit(limit).pluck(:account_id, :reason)
-  def key
-    :global
-  end
-
-  def get(account, skip_account_ids: [], limit: 40)
-    account_ids = account_ids_for_locale(I18n.locale.to_s.split(/[_-]/).first) - [account.id] - skip_account_ids
-
-    as_ordered_suggestions(
-      scope(account).where(id: account_ids),
-      account_ids
-    ).take(limit)
-  end
-
-  def remove(_account, _target_account_id)
-    nil
   end
 
   private
 
-  def scope(account)
+  def content_locale
-    Account.searchable
+    I18n.locale.to_s.split(/[_-]/).first
-           .followable_by(account)
-           .not_excluded_by_account(account)
-           .not_domain_blocked_by_account(account)
-  end
-
-  def account_ids_for_locale(locale)
-    redis.zrevrange("follow_recommendations:#{locale}", 0, -1).map(&:to_i)
-  end
-
-  def to_ordered_list_key(account)
-    account.id
   end
 end

app/models/account_suggestions/past_interactions_source.rb

@@ -1,36 +0,0 @@
-# frozen_string_literal: true
-
-class AccountSuggestions::PastInteractionsSource < AccountSuggestions::Source
-  include Redisable
-
-  def key
-    :past_interactions
-  end
-
-  def get(account, skip_account_ids: [], limit: 40)
-    account_ids = account_ids_for_account(account.id, limit + skip_account_ids.size) - skip_account_ids
-
-    as_ordered_suggestions(
-      scope.where(id: account_ids),
-      account_ids
-    ).take(limit)
-  end
-
-  def remove(account, target_account_id)
-    redis.zrem("interactions:#{account.id}", target_account_id)
-  end
-
-  private
-
-  def scope
-    Account.searchable
-  end
-
-  def account_ids_for_account(account_id, limit)
-    redis.zrevrange("interactions:#{account_id}", 0, limit).map(&:to_i)
-  end
-
-  def to_ordered_list_key(account)
-    account.id
-  end
-end

app/models/account_suggestions/setting_source.rb

@@ -1,32 +1,18 @@
 # frozen_string_literal: true
 
 class AccountSuggestions::SettingSource < AccountSuggestions::Source
-  def key
+  def get(account, limit: 10)
-    :staff
+    if setting_enabled?
+      base_account_scope(account).where(setting_to_where_condition).limit(limit).pluck(:id).zip([key].cycle)
+    else
+      []
     end
-
-  def get(account, skip_account_ids: [], limit: 40)
-    return [] unless setting_enabled?
-
-    as_ordered_suggestions(
-      scope(account).where(setting_to_where_condition).where.not(id: skip_account_ids),
-      usernames_and_domains
-    ).take(limit)
-  end
-
-  def remove(_account, _target_account_id)
-    nil
   end
 
   private
 
-  def scope(account)
+  def key
-    Account.searchable
+    :featured
-           .followable_by(account)
-           .not_excluded_by_account(account)
-           .not_domain_blocked_by_account(account)
-           .where(locked: false)
-           .where.not(id: account.id)
   end
 
   def usernames_and_domains
@@ -61,8 +47,4 @@ class AccountSuggestions::SettingSource < AccountSuggestions::Source
   def setting
     Setting.bootstrap_timeline_accounts
   end
-
-  def to_ordered_list_key(account)
-    [account.username.downcase, account.domain&.downcase]
-  end
 end

app/models/account_suggestions/similar_profiles_source.rb

@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+class AccountSuggestions::SimilarProfilesSource < AccountSuggestions::Source
+  class QueryBuilder < AccountSearchService::QueryBuilder
+    def must_clauses
+      [
+        {
+          more_like_this: {
+            fields: %w(text text.stemmed),
+            like: @query.map { |id| { _index: 'accounts', _id: id } },
+          },
+        },
+
+        {
+          term: {
+            properties: 'discoverable',
+          },
+        },
+      ]
+    end
+
+    def must_not_clauses
+      [
+        {
+          terms: {
+            id: following_ids,
+          },
+        },
+
+        {
+          term: {
+            properties: 'bot',
+          },
+        },
+      ]
+    end
+
+    def should_clauses
+      {
+        term: {
+          properties: {
+            value: 'verified',
+            boost: 2,
+          },
+        },
+      }
+    end
+  end
+
+  def get(account, limit: 10)
+    recently_followed_account_ids = account.active_relationships.recent.limit(5).pluck(:target_account_id)
+
+    if Chewy.enabled? && !recently_followed_account_ids.empty?
+      QueryBuilder.new(recently_followed_account_ids, account).build.limit(limit).hits.pluck('_id').map(&:to_i).zip([key].cycle)
+    else
+      []
+    end
+  rescue Faraday::ConnectionFailed
+    []
+  end
+
+  private
+
+  def key
+    :similar_to_recently_followed
+  end
+end

app/models/account_suggestions/source.rb

@@ -1,34 +1,18 @@
 # frozen_string_literal: true
 
 class AccountSuggestions::Source
-  def key
-    raise NotImplementedError
-  end
-
   def get(_account, **kwargs)
     raise NotImplementedError
   end
 
-  def remove(_account, target_account_id)
-    raise NotImplementedError
-  end
-
   protected
 
-  def as_ordered_suggestions(scope, ordered_list)
+  def base_account_scope(account)
-    return [] if ordered_list.empty?
+    Account.searchable
-
+           .followable_by(account)
-    map = scope.index_by { |account| to_ordered_list_key(account) }
+           .not_excluded_by_account(account)
-
+           .not_domain_blocked_by_account(account)
-    ordered_list.filter_map { |ordered_list_key| map[ordered_list_key] }.map do |account|
+           .where.not(id: account.id)
-      AccountSuggestions::Suggestion.new(
+           .joins("LEFT OUTER JOIN follow_recommendation_mutes ON follow_recommendation_mutes.target_account_id = accounts.id AND follow_recommendation_mutes.account_id = #{account.id}").where(follow_recommendation_mutes: { target_account_id: nil })
-        account: account,
-        source: key
-      )
-    end
-  end
-
-  def to_ordered_list_key(_account)
-    raise NotImplementedError
   end
 end

app/models/block.rb

@@ -26,15 +26,20 @@ class Block < ApplicationRecord
   end
 
   before_validation :set_uri, only: :create
-  after_commit :remove_blocking_cache
+  after_commit :invalidate_blocking_cache
+  after_commit :invalidate_follow_recommendations_cache
 
   private
 
-  def remove_blocking_cache
+  def invalidate_blocking_cache
     Rails.cache.delete("exclude_account_ids_for:#{account_id}")
     Rails.cache.delete("exclude_account_ids_for:#{target_account_id}")
   end
 
+  def invalidate_follow_recommendations_cache
+    Rails.cache.delete("follow_recommendations/#{account_id}")
+  end
+
   def set_uri
     self.uri = ActivityPub::TagManager.instance.generate_uri_for(self) if uri.nil?
   end

app/models/concerns/account/associations.rb

@@ -64,6 +64,7 @@ module Account::Associations
     has_one :deletion_request, class_name: 'AccountDeletionRequest', inverse_of: :account, dependent: :destroy
 
     # Follow recommendations
+    has_one :follow_recommendation, inverse_of: :account, dependent: nil
     has_one :follow_recommendation_suppression, inverse_of: :account, dependent: :destroy
 
     # Account statuses cleanup policy

app/models/concerns/account/interactions.rb

@@ -116,8 +116,6 @@ module Account::Interactions
 
     rel.save! if rel.changed?
 
-    remove_potential_friendship(other_account)
-
     rel
   end
 
@@ -131,13 +129,10 @@ module Account::Interactions
 
     rel.save! if rel.changed?
 
-    remove_potential_friendship(other_account)
-
     rel
   end
 
   def block!(other_account, uri: nil)
-    remove_potential_friendship(other_account)
     block_relationships.create_with(uri: uri)
                        .find_or_create_by!(target_account: other_account)
   end
@@ -148,8 +143,6 @@ module Account::Interactions
     mute.expires_in = duration.zero? ? nil : duration
     mute.save!
 
-    remove_potential_friendship(other_account)
-
     # When toggling a mute between hiding and allowing notifications, the mute will already exist, so the find_or_create_by! call will return the existing Mute without updating the hide_notifications attribute. Therefore, we check that hide_notifications? is what we want and set it if it isn't.
     mute.update!(hide_notifications: notifications) if mute.hide_notifications? != notifications
 
@@ -307,10 +300,4 @@ module Account::Interactions
       domain_blocking_by_domain: Account.domain_blocking_map_by_domain(domains, id),
     })
   end
-
-  private
-
-  def remove_potential_friendship(other_account)
-    PotentialFriendshipTracker.remove(id, other_account.id)
-  end
 end

app/models/concerns/account/search.rb

@@ -116,6 +116,7 @@ module Account::Search
     [].tap do |properties|
       properties << 'bot' if bot?
       properties << 'verified' if fields.any?(&:verified?)
+      properties << 'discoverable' if discoverable?
     end
   end
 

app/models/follow.rb

@@ -44,10 +44,10 @@ class Follow < ApplicationRecord
 
   before_validation :set_uri, only: :create
   after_create :increment_cache_counters
-  after_create :invalidate_hash_cache
   after_destroy :remove_endorsements
   after_destroy :decrement_cache_counters
-  after_destroy :invalidate_hash_cache
+  after_commit :invalidate_follow_recommendations_cache
+  after_commit :invalidate_hash_cache
 
   private
 
@@ -74,4 +74,8 @@ class Follow < ApplicationRecord
 
     Rails.cache.delete("followers_hash:#{target_account_id}:#{account.synchronization_uri_prefix}")
   end
+
+  def invalidate_follow_recommendations_cache
+    Rails.cache.delete("follow_recommendations/#{account_id}")
+  end
 end

app/models/follow_recommendation_filter.rb

@@ -17,12 +17,9 @@ class FollowRecommendationFilter
 
   def results
     if params['status'] == 'suppressed'
-      Account.joins(:follow_recommendation_suppression).order(FollowRecommendationSuppression.arel_table[:id].desc).to_a
+      Account.includes(:account_stat).joins(:follow_recommendation_suppression).order(FollowRecommendationSuppression.arel_table[:id].desc)
     else
-      account_ids = redis.zrevrange("follow_recommendations:#{@language}", 0, -1).map(&:to_i)
+      Account.includes(:account_stat).joins(:follow_recommendation).merge(FollowRecommendation.localized(@language).order(rank: :desc))
-      accounts    = Account.where(id: account_ids).index_by(&:id)
-
-      account_ids.filter_map { |id| accounts[id] }
     end
   end
 end

app/models/follow_recommendation_mute.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: follow_recommendation_mutes
+#
+#  id                :bigint(8)        not null, primary key
+#  account_id        :bigint(8)        not null
+#  target_account_id :bigint(8)        not null
+#  created_at        :datetime         not null
+#  updated_at        :datetime         not null
+#
+class FollowRecommendationMute < ApplicationRecord
+  belongs_to :account
+  belongs_to :target_account, class_name: 'Account'
+
+  validates :target_account, uniqueness: { scope: :account_id }
+
+  after_commit :invalidate_follow_recommendations_cache
+
+  private
+
+  def invalidate_follow_recommendations_cache
+    Rails.cache.delete("follow_recommendations/#{account_id}")
+  end
+end

app/models/follow_recommendation_suppression.rb

@@ -11,19 +11,5 @@
 #
 
 class FollowRecommendationSuppression < ApplicationRecord
-  include Redisable
-
   belongs_to :account
-
-  after_commit :remove_follow_recommendations, on: :create
-
-  private
-
-  def remove_follow_recommendations
-    redis.pipelined do |pipeline|
-      I18n.available_locales.each do |locale|
-        pipeline.zrem("follow_recommendations:#{locale}", account_id)
-      end
-    end
-  end
 end

app/models/follow_request.rb

@@ -45,10 +45,15 @@ class FollowRequest < ApplicationRecord
   end
 
   before_validation :set_uri, only: :create
+  after_commit :invalidate_follow_recommendations_cache
 
   private
 
   def set_uri
     self.uri = ActivityPub::TagManager.instance.generate_uri_for(self) if uri.nil?
   end
+
+  def invalidate_follow_recommendations_cache
+    Rails.cache.delete("follow_recommendations/#{account_id}")
+  end
 end

app/models/mute.rb

@@ -23,11 +23,16 @@ class Mute < ApplicationRecord
 
   validates :account_id, uniqueness: { scope: :target_account_id }
 
-  after_commit :remove_blocking_cache
+  after_commit :invalidate_blocking_cache
+  after_commit :invalidate_follow_recommendations_cache
 
   private
 
-  def remove_blocking_cache
+  def invalidate_blocking_cache
     Rails.cache.delete("exclude_account_ids_for:#{account_id}")
   end
+
+  def invalidate_follow_recommendations_cache
+    Rails.cache.delete("follow_recommendations/#{account_id}")
+  end
 end

app/models/preview_cards_status.rb

@@ -4,8 +4,8 @@
 #
 # Table name: preview_cards_statuses
 #
-#  preview_card_id :bigint(8)        not null
+#  preview_card_id :bigint(8)        not null, primary key
-#  status_id       :bigint(8)        not null
+#  status_id       :bigint(8)        not null, primary key
 #  url             :string
 #
 class PreviewCardsStatus < ApplicationRecord

app/services/account_search_service.rb

@@ -23,6 +23,7 @@ class AccountSearchService < BaseService
               query: {
                 bool: {
                   must: must_clauses,
+                  must_not: must_not_clauses,
                 },
               },
 
@@ -49,6 +50,10 @@ class AccountSearchService < BaseService
       end
     end
 
+    def must_not_clauses
+      []
+    end
+
     def should_clauses
       if @account && !@options[:following]
         [boost_following_query]

app/services/favourite_service.rb

@@ -20,7 +20,7 @@ class FavouriteService < BaseService
     Trends.statuses.register(status)
 
     create_notification(favourite)
-    bump_potential_friendship(account, status)
+    increment_statistics
 
     favourite
   end
@@ -37,11 +37,8 @@ class FavouriteService < BaseService
     end
   end
 
-  def bump_potential_friendship(account, status)
+  def increment_statistics
     ActivityTracker.increment('activity:interactions')
-    return if account.following?(status.account_id)
-
-    PotentialFriendshipTracker.record(account.id, status.account_id, :favourite)
   end
 
   def build_json(favourite)

app/services/post_status_service.rb

@@ -178,9 +178,6 @@ class PostStatusService < BaseService
     return if !@status.reply? || @account.id == @status.in_reply_to_account_id
 
     ActivityTracker.increment('activity:interactions')
-    return if @account.following?(@status.in_reply_to_account_id)
-
-    PotentialFriendshipTracker.record(@account.id, @status.in_reply_to_account_id, :reply)
   end
 
   def status_attributes

app/services/reblog_service.rb

@@ -33,7 +33,7 @@ class ReblogService < BaseService
     ActivityPub::DistributionWorker.perform_async(reblog.id)
 
     create_notification(reblog)
-    bump_potential_friendship(account, reblog)
+    increment_statistics
 
     reblog
   end
@@ -50,12 +50,8 @@ class ReblogService < BaseService
     end
   end
 
-  def bump_potential_friendship(account, reblog)
+  def increment_statistics
     ActivityTracker.increment('activity:interactions')
-
-    return if account.following?(reblog.reblog.account_id)
-
-    PotentialFriendshipTracker.record(account.id, reblog.reblog.account_id, :reblog)
   end
 
   def build_json(reblog)

app/views/admin/follow_recommendations/show.html.haml

@@ -38,3 +38,5 @@
         = nothing_here 'nothing-here--under-tabs'
       - else
         = render partial: 'account', collection: @accounts, locals: { f: f }
+
+= paginate @accounts

app/workers/scheduler/follow_recommendations_scheduler.rb

@@ -2,61 +2,11 @@
 
 class Scheduler::FollowRecommendationsScheduler
   include Sidekiq::Worker
-  include Redisable
 
   sidekiq_options retry: 0, lock: :until_executed, lock_ttl: 1.day.to_i
 
-  # The maximum number of accounts that can be requested in one page from the
-  # API is 80, and the suggestions API does not allow pagination. This number
-  # leaves some room for accounts being filtered during live access
-  SET_SIZE = 100
-
   def perform
-    # Maintaining a materialized view speeds-up subsequent queries significantly
     AccountSummary.refresh
     FollowRecommendation.refresh
-
-    fallback_recommendations = FollowRecommendation.order(rank: :desc).limit(SET_SIZE)
-
-    Trends.available_locales.each do |locale|
-      recommendations = if AccountSummary.safe.filtered.localized(locale).exists? # We can skip the work if no accounts with that language exist
-                          FollowRecommendation.localized(locale).order(rank: :desc).limit(SET_SIZE).map { |recommendation| [recommendation.rank, recommendation.account_id] }
-                        else
-                          []
-                        end
-
-      # Use language-agnostic results if there are not enough language-specific ones
-      missing = SET_SIZE - recommendations.size
-
-      if missing.positive? && fallback_recommendations.size.positive?
-        max_fallback_rank = fallback_recommendations.first.rank || 0
-
-        # Language-specific results should be above language-agnostic ones,
-        # otherwise language-agnostic ones will always overshadow them
-        recommendations.map! { |(rank, account_id)| [rank + max_fallback_rank, account_id] }
-
-        added = 0
-
-        fallback_recommendations.each do |recommendation|
-          next if recommendations.any? { |(_, account_id)| account_id == recommendation.account_id }
-
-          recommendations << [recommendation.rank, recommendation.account_id]
-          added += 1
-
-          break if added >= missing
-        end
-      end
-
-      redis.multi do |multi|
-        multi.del(key(locale))
-        multi.zadd(key(locale), recommendations)
-      end
-    end
-  end
-
-  private
-
-  def key(locale)
-    "follow_recommendations:#{locale}"
   end
 end

db/migrate/20231211234923_create_follow_recommendation_mutes.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class CreateFollowRecommendationMutes < ActiveRecord::Migration[7.1]
+  def change
+    create_table :follow_recommendation_mutes do |t|
+      t.references :account, null: false, foreign_key: { on_delete: :cascade }, index: false
+      t.references :target_account, null: false, foreign_key: { to_table: 'accounts', on_delete: :cascade }
+
+      t.timestamps
+    end
+
+    add_index :follow_recommendation_mutes, [:account_id, :target_account_id], unique: true
+  end
+end

db/migrate/20231212073317_add_languages_index_to_account_summaries.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AddLanguagesIndexToAccountSummaries < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def change
+    add_index :account_summaries, [:account_id, :language, :sensitive], algorithm: :concurrently
+  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_10_06_183200) do
+ActiveRecord::Schema[7.1].define(version: 2023_12_12_073317) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -474,6 +474,15 @@ ActiveRecord::Schema[7.0].define(version: 2023_10_06_183200) do
     t.index ["tag_id"], name: "index_featured_tags_on_tag_id"
   end
 
+  create_table "follow_recommendation_mutes", force: :cascade do |t|
+    t.bigint "account_id", null: false
+    t.bigint "target_account_id", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id", "target_account_id"], name: "idx_on_account_id_target_account_id_a8c8ddf44e", unique: true
+    t.index ["target_account_id"], name: "index_follow_recommendation_mutes_on_target_account_id"
+  end
+
   create_table "follow_recommendation_suppressions", force: :cascade do |t|
     t.bigint "account_id", null: false
     t.datetime "created_at", null: false
@@ -1209,6 +1218,8 @@ ActiveRecord::Schema[7.0].define(version: 2023_10_06_183200) do
   add_foreign_key "favourites", "statuses", name: "fk_b0e856845e", on_delete: :cascade
   add_foreign_key "featured_tags", "accounts", on_delete: :cascade
   add_foreign_key "featured_tags", "tags", on_delete: :cascade
+  add_foreign_key "follow_recommendation_mutes", "accounts", column: "target_account_id", on_delete: :cascade
+  add_foreign_key "follow_recommendation_mutes", "accounts", on_delete: :cascade
   add_foreign_key "follow_recommendation_suppressions", "accounts", on_delete: :cascade
   add_foreign_key "follow_requests", "accounts", column: "target_account_id", name: "fk_9291ec025d", on_delete: :cascade
   add_foreign_key "follow_requests", "accounts", name: "fk_76d644b0e7", on_delete: :cascade
@@ -1341,6 +1352,7 @@ ActiveRecord::Schema[7.0].define(version: 2023_10_06_183200) do
     WHERE ((accounts.suspended_at IS NULL) AND (accounts.silenced_at IS NULL) AND (accounts.moved_to_account_id IS NULL) AND (accounts.discoverable = true) AND (accounts.locked = false))
     GROUP BY accounts.id;
   SQL
+  add_index "account_summaries", ["account_id", "language", "sensitive"], name: "idx_on_account_id_language_sensitive_250461e1eb"
   add_index "account_summaries", ["account_id"], name: "index_account_summaries_on_account_id", unique: true
 
   create_view "global_follow_recommendations", materialized: true, sql_definition: <<-SQL

spec/requests/api/v1/suggestions_spec.rb

@@ -18,8 +18,7 @@ RSpec.describe 'Suggestions' do
     let(:params) { {} }
 
     before do
-      PotentialFriendshipTracker.record(user.account_id, bob.id, :reblog)
+      Setting.bootstrap_timeline_accounts = [bob, jeff].map(&:acct).join(',')
-      PotentialFriendshipTracker.record(user.account_id, jeff.id, :favourite)
     end
 
     it_behaves_like 'forbidden for wrong scope', 'write'
@@ -65,17 +64,15 @@ RSpec.describe 'Suggestions' do
       delete "/api/v1/suggestions/#{jeff.id}", headers: headers
     end
 
-    let(:suggestions_source) { instance_double(AccountSuggestions::PastInteractionsSource, remove: nil) }
     let(:bob) { Fabricate(:account) }
     let(:jeff) { Fabricate(:account) }
+    let(:scopes) { 'write' }
 
     before do
-      PotentialFriendshipTracker.record(user.account_id, bob.id, :reblog)
+      Setting.bootstrap_timeline_accounts = [bob, jeff].map(&:acct).join(',')
-      PotentialFriendshipTracker.record(user.account_id, jeff.id, :favourite)
-      allow(AccountSuggestions::PastInteractionsSource).to receive(:new).and_return(suggestions_source)
     end
 
-    it_behaves_like 'forbidden for wrong scope', 'write'
+    it_behaves_like 'forbidden for wrong scope', 'read'
 
     it 'returns http success' do
       subject
@@ -86,8 +83,7 @@ RSpec.describe 'Suggestions' do
     it 'removes the specified suggestion' do
       subject
 
-      expect(suggestions_source).to have_received(:remove).with(user.account, jeff.id.to_s).once
+      expect(FollowRecommendationMute.exists?(account: user.account, target_account: jeff)).to be true
-      expect(suggestions_source).to_not have_received(:remove).with(user.account, bob.id.to_s)
     end
 
     context 'without an authorization header' do

spec/workers/scheduler/follow_recommendations_scheduler_spec.rb

@@ -29,14 +29,12 @@ describe Scheduler::FollowRecommendationsScheduler do
 
       it 'creates recommendations' do
         expect { scheduled_run }.to change(FollowRecommendation, :count).from(0).to(target_accounts.size)
-        expect(redis.zrange('follow_recommendations:en', 0, -1)).to match_array(target_accounts.pluck(:id).map(&:to_s))
       end
     end
 
     context 'when there are no accounts to recommend' do
       it 'does not create follow recommendations' do
         expect { scheduled_run }.to_not change(FollowRecommendation, :count)
-        expect(redis.zrange('follow_recommendations:en', 0, -1)).to be_empty
       end
     end
   end