class PromotionCode < ApplicationRecord
  # Validations
  validates :code, presence: true, uniqueness: true
  validates :discount_amount_cents, numericality: { greater_than_or_equal_to: 0 }

  # Scopes
  scope :active, -> { where(active: true) }
  scope :expired, -> { where("expires_at < ? OR active = ?", Time.current, false) }
  scope :valid, -> { active.where("expires_at > ? OR expires_at IS NULL", Time.current) }

  # Callbacks
  before_create :increment_uses_count

  # Associations
  has_many :order_promotion_codes
  has_many :orders, through: :order_promotion_codes

  private

  def increment_uses_count
    self.uses_count ||= 0
  end
end