module ExactTargetRest
  class TriggeredSend
    # Execute TriggeredSends to one or several subscribers.
    #
    # @param authorization [Authorization]
    # @param external_key [String] The string that identifies the TriggeredSend
    # @param snake_to_camel [Boolean] Attributes should be converted to CamelCase? (default true)
    def initialize(authorization, external_key, snake_to_camel: true)
      @authorization = authorization
      @external_key = external_key
      @snake_to_camel = snake_to_camel
    end

    # TriggeredSend for just one subscriber.
    # @param to_address [String] Email to send.
    # @param subscriber_key [String] SubscriberKey (it uses Email if not set).
    # @param data_extension_attributes [{Symbol => Object}] List of attributes (in snake_case)
    #   that will be used in TriggeredSend and will be saved in related DataExtension
    #   (in CamelCase).
    def send_one(
      email_address:,
      subscriber_key: email_address,
      ** data_extension_attributes
      )
      with_options(
        email_address: email_address,
        subscriber_key: subscriber_key,
        subscriber_attributes: prepare_attributes(data_extension_attributes)
      ).deliver
    end

    # Load attributes and return "self". To send using async methods.
    # @param request_type [String] ASYNC or SYNC.
    # @param to_address [String] Email to send.
    # @param subscriber_key [String] SubscriberKey.
    # => it uses Email if not set
    # @param from_address [String] Sender email address.
    # @param from_name [String] Sender name.
    # @param subscriber_attributes [{String => String, ...}] List of attributes
    # => Keys as Strings (when your ExactTarget's fields doesn't have a pattern)
    def with_options(
      request_type: "ASYNC",
      email_address:,
      subscriber_key: email_address,
      from_address: "",
      from_name: "",
      subscriber_attributes: {}
      )
      @request_type = request_type
      @email_address = email_address
      @subscriber_key = subscriber_key
      @from_address = from_address
      @from_name = from_name
      @subscriber_attributes = subscriber_attributes

      self
    end

    # TriggeredSend with loaded attributes.
    def deliver
      tries ||= 1

      @authorization.with_authorization do |access_token|
        resp = endpoint.post do |p|
          p.url(format(TRIGGERED_SEND_PATH, URI.encode(@external_key)))
          p.headers['Authorization'] = "Bearer #{access_token}"
          p.body = {
            From: {
              Address: @from_address,
              Name: @from_name
            },
            To: {
              Address: @email_address,
              SubscriberKey: @subscriber_key,
              ContactAttributes: {
                  SubscriberAttributes: @subscriber_attributes
              }
            },
            OPTIONS: {
              RequestType: @request_type
            }
          }
        end
        raise NotAuthorizedError if resp.status == 401
        resp
      end
    rescue NotAuthorizedError
      tries -= 1
      retry if tries >= 0
      raise NotAuthorizedError
    end

    protected

    def endpoint
      Faraday.new(url: TRIGGERED_SEND_URL) do |f|
        f.request :json
        f.response :json, content_type: /\bjson$/
        f.adapter FARADAY_ADAPTER
      end
    end

    def prepare_attributes(attributes)
      @snake_to_camel ? attributes.snake_to_camel : attributes
    end
  end
end