class Customer < ApplicationRecord
  self.primary_key = "customer_id"

  before_create :generate_custom_id
  has_many :orders
  has_many :sales

  validates_presence_of :name, :contact_no
  validates :contact_no, uniqueness: true

  def lastest_invoices
    sales.where(:customer_id => self.id).order("created_at desc").limit(5)
  end

  private
  def generate_custom_id
    self.customer_id = SeedGenerator.generate_id(self.class.name, "CUS")
  end
end