require "uri"

module Backup
  module Notifier
    class Pushover < Base
      ##
      # The API User Token
      attr_accessor :user

      ##
      # The API Application Token
      attr_accessor :token

      ##
      # The user's device identifier to sent the message directly to,
      # rather than all of the user's devices
      attr_accessor :device

      ##
      # The message title
      attr_accessor :title

      ##
      # The priority of the notification
      attr_accessor :priority

      def initialize(model, &block)
        super
        instance_eval(&block) if block_given?
      end

      private

      ##
      # Notify the user of the backup operation results.
      #
      # `status` indicates one of the following:
      #
      # `:success`
      # : The backup completed successfully.
      # : Notification will be sent if `on_success` is `true`.
      #
      # `:warning`
      # : The backup completed successfully, but warnings were logged.
      # : Notification will be sent if `on_warning` or `on_success` is `true`.
      #
      # `:failure`
      # : The backup operation failed.
      # : Notification will be sent if `on_warning` or `on_success` is `true`.
      #
      def notify!(status)
        send_message(message.call(model, status: status_data_for(status)))
      end

      def send_message(message)
        uri = "https://api.pushover.net/1/messages.json"
        data = { user: user, token: token, message: message }
        [:device, :title, :priority].each do |param|
          val = send(param)
          data.merge!(param => val) if val
        end
        options = {
          headers: { "Content-Type" => "application/x-www-form-urlencoded" },
          body: URI.encode_www_form(data)
        }
        options[:expects] = 200 # raise error if unsuccessful
        Excon.post(uri, options)
      end
    end
  end
end