require 'open-uri'
require 'rexml/document'

module Ym4r
  module GmPlugin
    module Geocoding

      GEO_SUCCESS = 200
      GEO_MISSING_ADDRESS = 601
      GEO_UNKNOWN_ADDRESS = 602
      GEO_UNAVAILABLE_ADDRESS = 603
      GEO_BAD_KEY = 610
      GEO_TOO_MANY_QUERIES = 620
      GEO_SERVER_ERROR = 500
      
      #Gets placemarks by querying the Google Maps Geocoding service with the +request+ string. Options can either an explicity GMaps API key (<tt>:key</tt>) or a host, (<tt>:host</tt>). 
      def self.get(request,options = {})
        api_key = ApiKey.get(options)
        sensor = options[:sensor] || false
        output =  options[:output] || "kml"
        output_encoding = options[:output_encoding] || "utf-8"
        url = "http://maps.google.com/maps/geo?q=#{URI.encode(request)}&key=#{api_key}&sensor=#{sensor}&output=#{output}&oe=#{output_encoding}"

        res = open(url).read

        case output.to_sym
          when :json
          res = eval(res.gsub(":","=>")) #!!!EVAL EVAL EVAL EVAL!!! hopefully we can trust google...
          placemarks = Placemarks.new(res['name'],res['Status']['code'])
          if res['Placemark']
            placemark = res['Placemark']
   
            placemark.each do |data|
              
              data_country = data['Country']['CountryNameCode'] rescue ""
              data_administrative = data['Country']['AdministrativeArea']['AdministrativeAreaName'] rescue ""
              data_sub_administrative = data['Country']['AdministrativeArea']['SubAdministrativeArea']['SubAdministrativeAreaName'] rescue ""
              data_locality = data['Country']['AdministrativeArea']['SubAdministrativeArea']['Locality']['LocalityName'] rescue ""
              data_dependent_locality = data['Country']['AdministrativeArea']['SubAdministrativeArea']['Locality']['DependentLocality']['DependentLocalityName'] rescue ""
              data_thoroughfare = data['Country']['AdministrativeArea']['SubAdministrativeArea']['Locality']['DependentLocality']['Thoroughfare']['ThoroughfareName'] rescue ""
              data_postal_code = data['Country']['AdministrativeArea']['SubAdministrativeArea']['Locality']['DependentLocality']['Thoroughfare']['PostalCode']['PostalCodeNumber'] rescue ""
              lon, lat = data['Point']['coordinates'][0,2]
              data_accuracy = data['Accuracy']
              unless data_accuracy.nil?
                data_accuracy = data_accuracy.to_i
              end
        
              placemarks << Geocoding::Placemark.new(data['address'],
                                                     data_country,
                                                     data_administrative,
                                                     data_sub_administrative,
                                                     data_locality,
                                                     data_dependent_locality,
                                                     data_thoroughfare,
                                                     data_postal_code,
                                                     lon, lat, data_accuracy)
                                                     
            end
          end
          when :kml, :xml
          
          doc = REXML::Document.new(res) 

          response = doc.elements['//Response']
          placemarks = Placemarks.new(response.elements['name'].text,response.elements['Status/code'].text.to_i)
          response.elements.each(".//Placemark") do |placemark|
            data = placemark.elements
            data_country = data['.//CountryNameCode']
            data_administrative = data['.//AdministrativeAreaName']
            data_sub_administrative = data['.//SubAdministrativeAreaName']
            data_locality = data['.//LocalityName']
            data_dependent_locality = data['.//DependentLocalityName']
            data_thoroughfare = data['.//ThoroughfareName']
            data_postal_code = data['.//PostalCodeNumber']
            lon, lat = data['.//coordinates'].text.split(",")[0..1].collect {|l| l.to_f }
            data_accuracy = data['.//*[local-name()="AddressDetails"]'].attributes['Accuracy']
            unless data_accuracy.nil?
               data_accuracy = data_accuracy.to_i
             end
            placemarks << Geocoding::Placemark.new(data['address'].text,
                                                   data_country.nil? ? "" : data_country.text,
                                                   data_administrative.nil? ? "" : data_administrative.text,
                                                   data_sub_administrative.nil? ? "" : data_sub_administrative.text,
                                                   data_locality.nil? ? "" : data_locality.text,
                                                   data_dependent_locality.nil? ? "" : data_dependent_locality.text,
                                                   data_thoroughfare.nil? ? "" : data_thoroughfare.text,
                                                   data_postal_code.nil? ? "" : data_postal_code.text,
                                                   lon, lat, data_accuracy )
          end
        end
                
        placemarks
      end

      #Group of placemarks returned by the Geocoding service. If the result is valid the +status+ attribute should be equal to <tt>Geocoding::GE0_SUCCESS</tt>
      class Placemarks < Array
        attr_accessor :name,:status

        def initialize(name,status)
          super(0)
          @name = name
          @status = status
        end
      end

      #A result from the Geocoding service.
      class Placemark < Struct.new(:address,:country_code,:administrative_area,:sub_administrative_area,:locality,:dependent_locality,:thoroughfare,:postal_code,:longitude,:latitude,:accuracy)
        def lonlat
          [longitude,latitude]
        end

        def latlon
          [latitude,longitude]
        end
      end
    end
  end
end