Generate code for client

app/models/p_customer.rb

@@ -65,6 +65,26 @@ class PCustomer < ApplicationRecord
   has_many :order_hists
 
   # before_validation :set_auth_token, on: [:create, :update]
+  before_validation do
+    if self.code.blank?
+      generate_code
+    end
+  end
+
+  def generate_code
+    if !self.code
+      last_used_code = self.class.all.order(code: :desc).limit(1)[0].code
+      last_number = last_used_code.match(/\d+/).to_s.to_i + 1
+
+      code = "CLI%04d" % [last_number]
+
+      while self.class.find_by(code: code)
+        last_number += 1
+        code = "CLI%04d" % [last_number]
+      end
+      self.code = code
+    end
+  end
 
 
   def self.qi_table_order