#146 PayPal Express Checkout

script/generate migration add_express_token_to_orders express_token:string express_payer_id:string
rake db:migrate

config.after_initialize do
  ActiveMerchant::Billing::Base.mode = :test
  paypal_options = {
    :login => "seller_1229899173_biz_api1.railscasts.com",
    :password => "FXWU58S7KXFC6HBE",
    :signature => "AGjv6SW.mTiKxtkm6L9DcSUCUgePAUDQ3L-kTdszkPG8mRfjaRZDYtSu"
  }
  ::STANDARD_GATEWAY = ActiveMerchant::Billing::PaypalGateway.new(paypal_options)
  ::EXPRESS_GATEWAY = ActiveMerchant::Billing::PaypalExpressGateway.new(paypal_options)
end

config.after_initialize do
  ActiveMerchant::Billing::Base.mode = :test
  ::STANDARD_GATEWAY = ActiveMerchant::Billing::BogusGateway.new
  ::EXPRESS_GATEWAY = ActiveMerchant::Billing::BogusGateway.new
end

config.after_initialize do
  ActiveMerchant::Billing::Base.mode = :production
  paypal_options = {
    :login => "seller_1229899173_biz_api1.railscasts.com",
    :password => "FXWU58S7KXFC6HBE",
    :signature => "AGjv6SW.mTiKxtkm6L9DcSUCUgePAUDQ3L-kTdszkPG8mRfjaRZDYtSu"
  }
  ::STANDARD_GATEWAY = ActiveMerchant::Billing::PaypalGateway.new(paypal_options)
  ::EXPRESS_GATEWAY = ActiveMerchant::Billing::PaypalExpressGateway.new(paypal_options)
end

map.resources :orders, :new => { :express => :get }

def express
  response = EXPRESS_GATEWAY.setup_purchase(current_cart.build_order.price_in_cents,
    :ip                => request.remote_ip,
    :return_url        => new_order_url,
    :cancel_return_url => products_url
  )
  redirect_to EXPRESS_GATEWAY.redirect_url_for(response.token)
end

def new
  @order = Order.new(:express_token => params[:token])
end

def purchase
  response = process_purchase
  transactions.create!(:action => "purchase", :amount => price_in_cents, :response => response)
  cart.update_attribute(:purchased_at, Time.now) if response.success?
  response.success?
end

def express_token=(token)
  write_attribute(:express_token, token)
  if new_record? && !token.blank?
    details = EXPRESS_GATEWAY.details_for(token)
    self.express_payer_id = details.payer_id
    self.first_name = details.params["first_name"]
    self.last_name = details.params["last_name"]
  end
end

private

def process_purchase
  if express_token.blank?
    STANDARD_GATEWAY.purchase(price_in_cents, credit_card, standard_purchase_options)
  else
    EXPRESS_GATEWAY.purchase(price_in_cents, express_purchase_options)
  end
end

def standard_purchase_options
  {
    :ip => ip_address,
    :billing_address => {
      :name     => "Ryan Bates",
      :address1 => "123 Main St.",
      :city     => "New York",
      :state    => "NY",
      :country  => "US",
      :zip      => "10001"
    }
  }
end

def express_purchase_options
  {
    :ip => ip_address,
    :token => express_token,
    :payer_id => express_payer_id
  }
end

def validate_card
  if express_token.blank? && !credit_card.valid?
    credit_card.errors.full_messages.each do |message|
      errors.add_to_base message
    end
  end
end

<%= link_to image_tag("https://www.paypal.com/en_US/i/btn/btn_xpressCheckout.gif"), express_new_order_path %>

<% form_for @order do |f| %>
  <%= f.error_messages %>
  <% if @order.express_token.blank? %>
    ...
  <% else %>
    <%= f.hidden_field :express_token %>
    <p>Name: <%=h @order.first_name %> <%=h @order.last_name %></p>
    <p>TODO Display order confirmation details</p>
  <% end %>
  <p><%= f.submit "Complete Order" %></p>
<% end %>