Adding unified streamable notifications

app/models/notification.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+class Notification < ApplicationRecord
+  include Paginable
+
+  belongs_to :account
+  belongs_to :activity, polymorphic: true
+
+  belongs_to :mention,   foreign_type: 'Mention',   foreign_key: 'activity_id'
+  belongs_to :status,    foreign_type: 'Status',    foreign_key: 'activity_id'
+  belongs_to :follow,    foreign_type: 'Follow',    foreign_key: 'activity_id'
+  belongs_to :favourite, foreign_type: 'Favourite', foreign_key: 'activity_id'
+
+  STATUS_INCLUDES = [:account, :media_attachments, mentions: :account, reblog: [:account, mentions: :account]].freeze
+
+  scope :with_includes, -> { includes(status: STATUS_INCLUDES, mention: [status: STATUS_INCLUDES], favourite: [:account, status: STATUS_INCLUDES], follow: :account) }
+
+  def type
+    case activity_type
+    when 'Status'
+      :reblog
+    else
+      activity_type.downcase.to_sym
+    end
+  end
+
+  def from_account
+    case type
+    when :mention
+      activity.status.account
+    when :follow, :favourite, :reblog
+      activity.account
+    end
+  end
+
+  def target_status
+    case type
+    when :reblog
+      activity.reblog
+    when :favourite, :mention
+      activity.status
+    end
+  end
+end