gem 'tbk'

class WebpayController < ApplicationController

  # ...

  # Start a payment
  def pay
    # Initialyze you commerce
    @commerce = TBK::Commerce.new({
      id: YOUR_COMMERCE_ID,
      key: YOUR_RSA_KEY
    })

    # Setup the payment
    @payment = TBK::Webpay::Payment.new({
      commerce: @commerce,
      amount: ORDER_AMOUNT,
      order_id: ORDER_ID,
      success_url: webpay_success_url,
      # Webpay can only access the HTTP protocol to a direct IP address (keep that in mind)
      confirmation_url: webpay_confirmation_url(host: SERVER_IP_ADDRESS, protocol: 'http'),

      # Optionaly supply:
      session_id: SOME_SESSION_VALUE,
      failure_url: webpay_failure_url # success_url is used by default
    })

    # Redirect the user to Webpay
    redirect_to @payment.redirect_url
  end

  # ...
end

class WebpayController < ApplicationController

  # ...

  # Confirmation callback executed from Webpay servers
  def confirmation
    # Initialyze you commerce
    @commerce = TBK::Commerce.new({
      id: YOUR_COMMERCE_ID,
      key: YOUR_RSA_KEY
    })

    # Read the confirmation data from the request
    @confirmation = TBK::Webpay::Confirmation.new({
      commerce: @commerce,
      post: request.raw_post
    })

    if # confirmation is invalid for some reason (wrong order_id or amount, double payment, etc...)
      render text: @confirmation.reject
      return # reject and stop execution
    end

    if @confirmation.success?
      # EXITO!
      # perform everything you have to do here.
    end

    # Acknowledge payment
    render text: @confirmation.acknowledge
  end

  # ...

end