require "xapo_sdk/version"
require "xapo_utils"

require "json"
require "uri"
require "yaml"

module XapoTools

  module_function 

  # Micro payment button configuration options.
  #
  # This function is intended to be a helper for creating empty micro
  # payments buttons configuration but also serves for documenting. A 
  # hash with the intended fields would give the same results.
  #
  # Attributes:
  #      sender_user_id (str): The id of the user sending the payment.
  #      sender_user_email (str, optional): The email of the user sending
  #          the payment.
  #      sender_user_cellphone (str, optional): The celphone number of the user
  #          sending the payment.
  #      receiver_user_id (str): The id of the user receiving the payment.
  #      receiver_user_email (str): The email of the user receiving the payment.
  #      pay_object_id (str): A payment identifier in the TPA context.
  #      amount_BIT (float, optional): The amount of bitcoins to be payed by the
  #          widget. If not specified here, it must be entered on payment basis.
  #      pay_type (str): The string representing the type of operation
  #          ("Tip", "Pay", "Deposit" or "Donate").
  def micro_payment_config
    return Hash[:sender_user_id => "", :sender_user_email => "", 
                :sender_user_cellphone => "", :receiver_user_id => "", 
                :receiver_user_email => "", :pay_object_id => "", 
                :amount_BIT => 0, :timestamp => XapoUtils.timestamp, 
                :pay_type => ""]
  end

  # Xapo's payment buttons snippet builder.
  #
  # This class allows the construction of 2 kind of widgets, *div* and
  # *iframe*. The result is a HTML snippet that could be embedded in a
  # web page for doing micro payments though a payment button.
  #
  # Attributes:
  #    service_url (str): The endpoint URL that returns the payment widget.
  #    app_id (str, optional): The id of the TPA for which the widget will be created.
  #    app_secret (str, optional): The TPA secret used to encrypt widget configuration.
  class MicroPayment    
    def initialize(service_url, app_id=nil, app_secret=nil)
      @service_url = service_url
      @app_id = app_id
      @app_secret = app_secret
    end

    def build_url(config)
      json_config = JSON.generate(config)
      
      if @app_secret == nil || @app_id == nil
        query_str = URI.encode_www_form(
          "payload" => json_config,
          "customization" => JSON.generate({"button_text" => config[:pay_type]})
        )
      else
        encrypted_config = XapoUtils.encrypt(json_config, @app_secret)

        query_str = URI.encode_www_form(
          "app_id" => @app_id, 
          "button_request" => encrypted_config,
          "customization" => JSON.generate({"button_text" => config[:pay_type]})
        )
      end

      widget_url = @service_url + "?" + query_str

      return widget_url
    end

    # Build an iframe HTML snippet in order to be embedded in apps.
    #
    # Args:
    #   config (MicroPaymentConfig): The button configuration options.
    #   See @MicroPaymentConfig.
    #
    # Returns:
    #   string: the iframe HTML snippet ot be embedded in a page.
    def build_iframe_widget(config)
      widget_url = build_url(config)

      snippet = YAML::load(<<-END)
      |
          <iframe id="tipButtonFrame" scrolling="no" frameborder="0"
              style="border:none; overflow:hidden; height:22px;"
              allowTransparency="true" src="#{widget_url}">
          </iframe>
      END

      return snippet
    end

    # Build div HTML snippet in order to be embedded in apps.
    #
    # Args:
    #   config (MicroPaymentConfig): The button configuration options.
    #   See @MicroPaymentConfig.
    #
    # Returns:
    #   string: the div HTML snippet ot be embedded in a page.
    def build_div_widget(config)
      widget_url = build_url(config)

      snippet = YAML::load(<<-END)
      |
          <div id="tipButtonDiv" class="tipButtonDiv"></div>
          <div id="tipButtonPopup" class="tipButtonPopup"></div>
          <script>
              $(document).ready(function() {{
                  $("#tipButtonDiv").load("#{widget_url}");
              }});
          </script>
      END

      return snippet
    end

    private :build_url
  end
end

module PayType
  TIP = "Tip"
  DONATE = "Donate"
  PAY = "Pay"
  DEPOSIT = "Deposit"
end