feat: Added the ability to create Instagram channel (#11182)

This PR is part of https://github.com/chatwoot/chatwoot/pull/11054 to
make the review cycle easier.

app/models/channel/instagram.rb

@@ -16,13 +16,47 @@
 #
 class Channel::Instagram < ApplicationRecord
   include Channelable
-
+  include Reauthorizable
   self.table_name = 'channel_instagram'
 
   validates :access_token, presence: true
   validates :instagram_id, uniqueness: true, presence: true
 
+  after_create_commit :subscribe
+  before_destroy :unsubscribe
+
   def name
     'Instagram'
   end
+
+  def subscribe
+    # ref https://developers.facebook.com/docs/instagram-platform/webhooks#enable-subscriptions
+    HTTParty.post(
+      "https://graph.instagram.com/v22.0/#{instagram_id}/subscribed_apps",
+      query: {
+        subscribed_fields: %w[messages message_reactions messaging_seen],
+        access_token: access_token
+      }
+    )
+  rescue StandardError => e
+    Rails.logger.debug { "Rescued: #{e.inspect}" }
+    true
+  end
+
+  def unsubscribe
+    HTTParty.delete(
+      "https://graph.instagram.com/v22.0/#{instagram_id}/subscribed_apps",
+      query: {
+        access_token: access_token
+      }
+    )
+    true
+  rescue StandardError => e
+    Rails.logger.debug { "Rescued: #{e.inspect}" }
+    true
+  end
+
+  def access_token
+    Instagram::RefreshOauthTokenService.new(channel: self).access_token
+  end
 end