feat: Add support for ascending and descending options in sort (#8542)

app/models/concerns/sort_handler.rb

@@ -1,41 +1,37 @@
 module SortHandler
   extend ActiveSupport::Concern
 
-  included do
-    def self.latest
-      order(last_activity_at: :desc)
+  class_methods do
+    def sort_on_last_activity_at(sort_direction = :desc)
+      order(last_activity_at: sort_direction)
     end
 
-    def self.sort_on_created_at
-      order(created_at: :asc)
+    def sort_on_created_at(sort_direction = :asc)
+      order(created_at: sort_direction)
     end
 
-    def self.last_messaged_conversations
+    def sort_on_priority(sort_direction = :desc)
+      order(generate_sql_query("priority #{sort_direction.to_s.upcase} NULLS LAST, last_activity_at DESC"))
+    end
+
+    def sort_on_waiting_since(sort_direction = :asc)
+      order(generate_sql_query("waiting_since #{sort_direction.to_s.upcase} NULLS LAST, created_at ASC"))
+    end
+
+    def last_messaged_conversations
       Message.except(:order).select(
         'DISTINCT ON (conversation_id) conversation_id, id, created_at, message_type'
       ).order('conversation_id, created_at DESC')
     end
 
-    def self.sort_on_last_user_message_at
-      order(
-        'grouped_conversations.message_type', 'grouped_conversations.created_at ASC'
-      )
+    def sort_on_last_user_message_at
+      order('grouped_conversations.message_type', 'grouped_conversations.created_at ASC')
     end
 
-    def self.sort_on_priority
-      order(
-        Arel::Nodes::SqlLiteral.new(
-          sanitize_sql_for_order('CASE WHEN priority IS NULL THEN 0 ELSE priority END DESC, last_activity_at DESC')
-        )
-      )
-    end
+    private
 
-    def self.sort_on_waiting_since
-      order(
-        Arel::Nodes::SqlLiteral.new(
-          sanitize_sql_for_order('CASE WHEN waiting_since IS NULL THEN now() ELSE waiting_since END ASC, created_at ASC')
-        )
-      )
+    def generate_sql_query(query)
+      Arel::Nodes::SqlLiteral.new(sanitize_sql_for_order(query))
     end
   end
 end