Open-Source-Access-Control-Web-Interface/app/models/ipn.rb

require 'net/http'
class Ipn < ActiveRecord::Base
  attr_accessible :data
  belongs_to :payment

  after_create :create_payment

  def self.new_from_dynamic_params(params)
    ipn = Ipn.new()

    ipn.attributes.each do |c|
      unless params[c.first.to_sym].nil?
        ipn[c.first.to_sym] = params[c.first.to_sym]
      end
    end

    return ipn
  end

  # Post back to Paypal to make sure it's valid
  def validate!
    uri = URI.parse('https://www.paypal.com/cgi-bin/webscr?cmd=_notify-validate')

    http = Net::HTTP.new(uri.host, uri.port)
    http.open_timeout = 60
    http.read_timeout = 60
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE
    http.use_ssl = true
    response = http.post(uri.request_uri, self.data,
                         'Content-Length' => "#{self.data.size}",
                         'User-Agent' => "Ruby on Rails"
                       ).body

    unless ["VERIFIED", "INVALID"].include?(response)
      Rails.logger.error "Faulty paypal result: #{response}"
      return false
    end
    unless response == "VERIFIED"
      Rails.logger.error "Invalid IPN: #{response}" 
      return false
    end

    return true
  end

  def link_payment
    create_payment
  end

  private
  def create_payment
    # find user by email, then by payee
    user = User.find_by_email(self.payer_email)
    user = User.find_by_payee(self.payer_email) if user.nil? && self.payer_email.present?

    # Only create payments if the IPN matches a member
    if user.present?
      # And is a payment (not a cancellation, etc)
      payment_types = ["subscr_payment","send_money"]
      if payment_types.include?(self.txn_type)
        # And a member level
        if User.member_levels[self.payment_gross.to_i].present?
          payment = Payment.new
          payment.date = Date.strptime(self.payment_date, "%H:%M:%S %b %e, %Y %Z")
          payment.user_id = user.id
          payment.amount = self.payment_gross
          if payment.save
            self.payment_id = payment.id
            self.save!
          else
            return [false, "Unable to link payment. Payment error: #{payment.errors.full_messages.first}"]
          end
        else
          return [false, "Unable to link payment. Couldn't find membership level '#{self.payment_gross.to_i}'."]
        end
      else
        return [false, "Unable to link payment. Transaction is a '#{self.txn_type}' instead of '#{payment_types.inspect}'."]
      end
    else
      return [false, "Unable to link payment. Couldn't find user/payee '#{self.payer_email}'."]
    end

    return [true]
  end

end