Add option to be notified when a followed user posts (#13546)

* Add bell button

Fix #4890

* Remove duplicate type from post-deployment migration

* Fix legacy class type mappings

* Improve query performance with better index

* Fix validation

* Remove redundant index from notifications

4 files changed, 47 insertions, 29 deletions

diff --git a/app/models/concerns/account_interactions.rb b/app/models/concerns/account_interactions.rb
index be7211f2c..427ebdae2 100644
--- a/app/models/concerns/account_interactions.rb
+++ b/app/models/concerns/account_interactions.rb
@@ -8,6 +8,7 @@ module AccountInteractions
       Follow.where(target_account_id: target_account_ids, account_id: account_id).each_with_object({}) do |follow, mapping|
         mapping[follow.target_account_id] = {
           reblogs: follow.show_reblogs?,
+          notify: follow.notify?,
         }
       end
     end
@@ -36,6 +37,7 @@ module AccountInteractions
       FollowRequest.where(target_account_id: target_account_ids, account_id: account_id).each_with_object({}) do |follow_request, mapping|
         mapping[follow_request.target_account_id] = {
           reblogs: follow_request.show_reblogs?,
+          notify: follow_request.notify?,
         }
       end
     end
@@ -95,25 +97,29 @@ module AccountInteractions
     has_many :announcement_mutes, dependent: :destroy
   end
 
-  def follow!(other_account, reblogs: nil, uri: nil, rate_limit: false)
-    reblogs = true if reblogs.nil?
-
-    rel = active_relationships.create_with(show_reblogs: reblogs, uri: uri, rate_limit: rate_limit)
+  def follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false)
+    rel = active_relationships.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit)
                               .find_or_create_by!(target_account: other_account)
 
-    rel.update!(show_reblogs: reblogs)
+    rel.show_reblogs = reblogs unless reblogs.nil?
+    rel.notify       = notify  unless notify.nil?
+
+    rel.save! if rel.changed?
+
     remove_potential_friendship(other_account)
 
     rel
   end
 
-  def request_follow!(other_account, reblogs: nil, uri: nil, rate_limit: false)
-    reblogs = true if reblogs.nil?
-
-    rel = follow_requests.create_with(show_reblogs: reblogs, uri: uri, rate_limit: rate_limit)
+  def request_follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false)
+    rel = follow_requests.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit)
                          .find_or_create_by!(target_account: other_account)
 
-    rel.update!(show_reblogs: reblogs)
+    rel.show_reblogs = reblogs unless reblogs.nil?
+    rel.notify       = notify  unless notify.nil?
+
+    rel.save! if rel.changed?
+
     remove_potential_friendship(other_account)
 
     rel
diff --git a/app/models/follow.rb b/app/models/follow.rb
index f3e48a2ed..0b4ddbf3f 100644
--- a/app/models/follow.rb
+++ b/app/models/follow.rb
@@ -10,6 +10,7 @@
 #  target_account_id :bigint(8)        not null
 #  show_reblogs      :boolean          default(TRUE), not null
 #  uri               :string
+#  notify            :boolean          default(FALSE), not null
 #
 
 class Follow < ApplicationRecord
@@ -34,7 +35,7 @@ class Follow < ApplicationRecord
   end
 
   def revoke_request!
-    FollowRequest.create!(account: account, target_account: target_account, show_reblogs: show_reblogs, uri: uri)
+    FollowRequest.create!(account: account, target_account: target_account, show_reblogs: show_reblogs, notify: notify, uri: uri)
     destroy!
   end
 
diff --git a/app/models/follow_request.rb b/app/models/follow_request.rb
index 3325e264c..c1f19149b 100644
--- a/app/models/follow_request.rb
+++ b/app/models/follow_request.rb
@@ -10,6 +10,7 @@
 #  target_account_id :bigint(8)        not null
 #  show_reblogs      :boolean          default(TRUE), not null
 #  uri               :string
+#  notify            :boolean          default(FALSE), not null
 #
 
 class FollowRequest < ApplicationRecord
@@ -28,7 +29,7 @@ class FollowRequest < ApplicationRecord
   validates_with FollowLimitValidator, on: :create
 
   def authorize!
-    account.follow!(target_account, reblogs: show_reblogs, uri: uri)
+    account.follow!(target_account, reblogs: show_reblogs, notify: notify, uri: uri)
     MergeWorker.perform_async(target_account.id, account.id) if account.local?
     destroy!
   end
diff --git a/app/models/notification.rb b/app/models/notification.rb
index 4d7a392b1..e83123c97 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -10,21 +10,34 @@
 #  updated_at      :datetime         not null
 #  account_id      :bigint(8)        not null
 #  from_account_id :bigint(8)        not null
+#  type            :string
 #
 
 class Notification < ApplicationRecord
+  self.inheritance_column = nil
+
   include Paginable
   include Cacheable
 
-  TYPE_CLASS_MAP = {
-    mention:        'Mention',
-    reblog:         'Status',
-    follow:         'Follow',
-    follow_request: 'FollowRequest',
-    favourite:      'Favourite',
-    poll:           'Poll',
+  LEGACY_TYPE_CLASS_MAP = {
+    'Mention'       => :mention,
+    'Status'        => :reblog,
+    'Follow'        => :follow,
+    'FollowRequest' => :follow_request,
+    'Favourite'     => :favourite,
+    'Poll'          => :poll,
   }.freeze
 
+  TYPES = %i(
+    mention
+    status
+    reblog
+    follow
+    follow_request
+    favourite
+    poll
+  ).freeze
+
   STATUS_INCLUDES = [:account, :application, :preloadable_poll, :media_attachments, :tags, active_mentions: :account, reblog: [:account, :application, :preloadable_poll, :media_attachments, :tags, active_mentions: :account]].freeze
 
   belongs_to :account, optional: true
@@ -38,29 +51,30 @@ class Notification < ApplicationRecord
   belongs_to :favourite,      foreign_type: 'Favourite',     foreign_key: 'activity_id', optional: true
   belongs_to :poll,           foreign_type: 'Poll',          foreign_key: 'activity_id', optional: true
 
-  validates :account_id, uniqueness: { scope: [:activity_type, :activity_id] }
-  validates :activity_type, inclusion: { in: TYPE_CLASS_MAP.values }
+  validates :type, inclusion: { in: TYPES }
 
   scope :without_suspended, -> { joins(:from_account).merge(Account.without_suspended) }
 
   scope :browserable, ->(exclude_types = [], account_id = nil) {
-    types = TYPE_CLASS_MAP.values - activity_types_from_types(exclude_types)
+    types = TYPES - exclude_types.map(&:to_sym)
 
     if account_id.nil?
-      where(activity_type: types)
+      where(type: types)
     else
-      where(activity_type: types, from_account_id: account_id)
+      where(type: types, from_account_id: account_id)
     end
   }
 
   cache_associated :from_account, status: STATUS_INCLUDES, mention: [status: STATUS_INCLUDES], favourite: [:account, status: STATUS_INCLUDES], follow: :account, follow_request: :account, poll: [status: STATUS_INCLUDES]
 
   def type
-    @type ||= TYPE_CLASS_MAP.invert[activity_type].to_sym
+    @type ||= (super || LEGACY_TYPE_CLASS_MAP[activity_type]).to_sym
   end
 
   def target_status
     case type
+    when :status
+      status
     when :reblog
       status&.reblog
     when :favourite
@@ -89,10 +103,6 @@ class Notification < ApplicationRecord
         item.target_status.account = accounts[item.target_status.account_id] if item.target_status
       end
     end
-
-    def activity_types_from_types(types)
-      types.map { |type| TYPE_CLASS_MAP[type.to_sym] }.compact
-    end
   end
 
   after_initialize :set_from_account