module Pay
  # Adds Pay methods to ActiveRecord models

  module Attributes
    extend ActiveSupport::Concern

    module CustomerExtension
      extend ActiveSupport::Concern

      included do
        has_many :pay_customers, class_name: "Pay::Customer", as: :owner, inverse_of: :owner
        has_many :charges, through: :pay_customers, class_name: "Pay::Charge"
        has_many :subscriptions, through: :pay_customers, class_name: "Pay::Subscription"
        has_one :payment_processor, -> { where(default: true, deleted_at: nil) }, class_name: "Pay::Customer", as: :owner, inverse_of: :owner

        after_commit :cancel_active_pay_subscriptions!, on: [:destroy]
      end

      # Changes a user's payment processor
      #
      # This has several effects:
      # - Finds or creates a Pay::Customer for the process and marks it as default
      # - Removes the default flag from all other Pay::Customers
      # - Removes the default flag from all Pay::PaymentMethods
      def set_payment_processor(processor_name, allow_fake: false, **attributes)
        raise Pay::Error, "Processor `#{processor_name}` is not allowed" if processor_name.to_s == "fake_processor" && !allow_fake

        ActiveRecord::Base.transaction do
          pay_customers.update_all(default: false)
          pay_customer = pay_customers.active.where(processor: processor_name).first_or_initialize
          pay_customer.update!(attributes.merge(default: true))
        end

        # Return new payment processor
        reload_payment_processor
      end

      def cancel_active_pay_subscriptions!
        subscriptions.active.each(&:cancel_now!)
      end
    end

    module MerchantExtension
      extend ActiveSupport::Concern

      included do
        has_many :pay_merchants, class_name: "Pay::Merchant", as: :owner, inverse_of: :owner
        has_one :merchant_processor, -> { where(default: true) }, class_name: "Pay::Merchant", as: :owner, inverse_of: :owner
      end

      def set_merchant_processor(processor_name, **attributes)
        ActiveRecord::Base.transaction do
          pay_merchants.update_all(default: false)
          pay_merchant = pay_merchants.where(processor: processor_name).first_or_initialize
          pay_merchant.update!(attributes.merge(default: true))
        end

        # Return new payment processor
        reload_merchant_processor
      end
    end

    class_methods do
      def pay_customer
        include Billable::SyncCustomer
        include CustomerExtension
      end

      def pay_merchant
        include MerchantExtension
      end
    end
  end
end