require 'httparty'
require 'builder'
require 'date'

module Trackerific
  module Services
    # Provides package tracking support for UPS.
    class UPS < Base
      self.register :ups

      include ::HTTParty
      format :xml

      base_uri case (ENV['RAILS_ENV'] || 'production')
      when 'production' then 'https://www.ups.com/ups.app/xml'
      else 'https://wwwcie.ups.com/ups.app/xml'
      end

      def initialize(options={})
        @options = options
      end

      # An Array of Regexp that matches valid UPS package IDs
      # @return [Array, Regexp] the regular expression
      # @api private
      def self.package_id_matchers
        [ /^.Z/, /^[HK].{10}$/ ]
      end

      # Tracks a UPS package
      # @param [String] package_id the package identifier
      # @return [Trackerific::Details] the tracking details
      # @raise [Trackerific::Error] raised when the server returns an error (invalid credentials, tracking package, etc.)
      # @example Track a package
      #   ups = Trackerific::UPS.new key: 'api key', user_id: 'user', password: 'secret'
      #   details = ups.track_package("1Z12345E0291980793")
      # @api public
      def track(id)
        @package_id = id
        # connect to UPS via HTTParty
        http_response = self.class.post('/Track', body: build_xml_request)
        # throw any HTTP errors
        http_response.error! unless http_response.code == 200
        # Check the response for errors, return a Trackerific::Error, or parse
        # the response from UPS and return a Trackerific::Details
        case http_response['TrackResponse']['Response']['ResponseStatusCode']
          when "0" then raise Trackerific::Error, parse_error_response(http_response)
          when "1" then return parse_success_response(http_response)
          else raise Trackerific::Error, "Invalid response code returned from server."
        end
      end

      protected

      # Parses the response from UPS
      # @return [Trackerific::Details]
      # @api private
      def parse_success_response(http_response)
        # get the activity from the UPS response
        activity = http_response['TrackResponse']['Shipment']['Package']['Activity']
        # if there's only one activity in the list, we need to put it in an array
        activity = [activity] if activity.is_a? Hash
        # UPS does not provide a summary, so we'll just use the last tracking status
        summary = activity.first['Status']['StatusType']['Description']
        events = []
        activity.each do |a|
          # the time format from UPS is HHMMSS, which cannot be directly converted
          # to a Ruby time.
          hours   = a['Time'][0..1]
          minutes = a['Time'][2..3]
          seconds = a['Time'][4..5]
          date    = Date.parse(a['Date'])
          date    = DateTime.parse("#{date} #{hours}:#{minutes}:#{seconds}")
          desc    = a['Status']['StatusType']['Description']
          loc     = a['ActivityLocation']['Address'].map {|k,v| v}.join(" ")
          events << Trackerific::Event.new(date, desc, loc)
        end

        Trackerific::Details.new(@package_id, summary, events)
      end

      # Parses a UPS tracking response, and returns any errors
      # @return [String] the UPS tracking error
      # @api private
      def parse_error_response(http_response)
        http_response['TrackResponse']['Response']['Error']['ErrorDescription']
      end

      # Builds the XML request to send to UPS for tracking a package
      # @return [String] the XML request
      # @api private
      def build_xml_request
        xml = ""
        builder = ::Builder::XmlMarkup.new(:target => xml)
        builder.AccessRequest do |ar|
          ar.AccessLicenseNumber @options[:key]
          ar.UserId @options[:user_id]
          ar.Password @options[:password]
        end
        builder.TrackRequest do |tr|
          tr.Request do |r|
            r.RequestAction 'Track'
            r.RequestOption 'activity'
          end
          tr.TrackingNumber @package_id
        end
        return xml
      end
    end
  end
end