chore: Migrate PubSub Token to contact inbox (#3434)

At present, the websocket pubsub tokens are present at the contact objects in chatwoot. A better approach would be to have these tokens at the contact_inbox object instead. This helps chatwoot to deliver the websocket events targetted to the specific widget connection, stop contact events from leaking into other chat sessions from the same contact.

Fixes #1682
Fixes #1664

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/models/concerns/pubsubable.rb

@@ -7,4 +7,10 @@ module Pubsubable
     # Used by the actionCable/PubSub Service we use for real time communications
     has_secure_token :pubsub_token
   end
+
+  def pubsub_token
+    # backfills tokens for existing records
+    regenerate_pubsub_token if self[:pubsub_token].blank?
+    self[:pubsub_token]
+  end
 end

app/models/contact.rb

@@ -25,7 +25,7 @@
 #
 
 class Contact < ApplicationRecord
-  include Pubsubable
+  # TODO: remove the pubsub_token attribute from this model in future.
   include Avatarable
   include AvailabilityStatusable
   include Labelable

app/models/contact_inbox.rb

@@ -4,6 +4,7 @@
 #
 #  id            :bigint           not null, primary key
 #  hmac_verified :boolean          default(FALSE)
+#  pubsub_token  :string
 #  created_at    :datetime         not null
 #  updated_at    :datetime         not null
 #  contact_id    :bigint
@@ -15,6 +16,7 @@
 #  index_contact_inboxes_on_contact_id              (contact_id)
 #  index_contact_inboxes_on_inbox_id                (inbox_id)
 #  index_contact_inboxes_on_inbox_id_and_source_id  (inbox_id,source_id) UNIQUE
+#  index_contact_inboxes_on_pubsub_token            (pubsub_token) UNIQUE
 #  index_contact_inboxes_on_source_id               (source_id)
 #
 # Foreign Keys
@@ -24,6 +26,7 @@
 #
 
 class ContactInbox < ApplicationRecord
+  include Pubsubable
   validates :inbox_id, presence: true
   validates :contact_id, presence: true
   validates :source_id, presence: true