validations

module EmailNormalization
  extend ActiveSupport::Concern

  included do
    attr_accessor :soft_warnings

class SlugValidator < ActiveModel::Validator
  SLUG_REGEX = /\A[a-z0-9]+(?:-[a-z0-9]+)*\z/

  def validate(record)
    slug = record.send(options[:attribute] || :slug)

# app/validators/order_validator.rb
class OrderValidator < ActiveModel::Validator
  def validate(record)
    validate_order_total(record)
    validate_items_availability(record)
    validate_shipping_address(record)

class AtLeastOneOfValidator < ActiveModel::Validator
  def validate(record)
    fields = Array(options[:fields])
    raise ArgumentError, "provide :fields" if fields.empty?

    return if fields.any? { |field| filled?(record.public_send(field)) }

class Category < ApplicationRecord
  has_many :products, dependent: :restrict_with_error
  has_many :subcategories,
           class_name: "Category",
           foreign_key: :parent_id,
           dependent: :restrict_with_error

class Order < ApplicationRecord
  has_many :line_items, dependent: :destroy, inverse_of: :order

  accepts_nested_attributes_for :line_items,
    reject_if: :all_blank,
    allow_destroy: true

class Order < ApplicationRecord
  has_many :line_items, inverse_of: :order, dependent: :destroy

  accepts_nested_attributes_for :line_items,
    allow_destroy: true,
    reject_if: ->(attrs) { attrs["product_id"].blank? && attrs["quantity"].blank? }

class Order < ApplicationRecord
  class InvalidTransition < StandardError; end

  enum status: { pending: 0, paid: 1, shipped: 2, cancelled: 3 }

  has_many :order_transitions, -> { order(:created_at) }, dependent: :destroy