January Contest: Ride4Ruby

ride4ruby.rb

#!/usr/bin/env ruby
require 'net/http'
require 'rexml/document'

module Ride4Ruby
  GOOGLE_MAPS_API_KEY = "your google key"

  @states = ["Alabama", "Alaska", "Arizona", "Arkansas", "California", "Colorado", "Connecticut", "Delaware", "District of Columbia", "Florida", "Georgia", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts", "Michigan", "Minnesota", "Mississippi", "Missouri", "Montana", "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", "New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota", "Tennessee", "Texas", "Utah", "Vermont", "Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming"]

  class Location 
    attr_accessor :address, :lng

    def initialize(options = {})
      options.each do |name, value|
        send("#{name}=", value)
      end
    end

    def is_farther_east_than(location)
      self.lng > location.lng
    end

    def is_farther_west_than(location)
      self.lng < location.lng
    end  

    def distance_between(location)
      uri = "http://maps.google.com/maps/api/directions/xml?origin=#{URI.escape @address}&destination=#{URI.escape location.address}&sensor=false&key=#{GOOGLE_MAPS_API_KEY}"    
      get_document(uri).elements["/DirectionsResponse/route/leg/distance/text"].text.to_s
    end

    def self.find_all(state)
      uri = "http://maps.google.com/maps/geo?q=#{URI.escape state}%20Ruby%20Street&output=xml&key=#{GOOGLE_MAPS_API_KEY}"
      locations = []    
      get_document(uri).each_element("//Placemark") do |e|
        country = e.elements["./AddressDetails/Country/CountryName"].text.to_s
        locations << Location.new(
          { :address => e.elements["./address"].text.to_s, 
            :lng => e.elements[".//coordinates"].text.to_s.split(',').first.to_f }) if country == "USA"
      end
      locations
    end

    def get_document(uri)
      self.class.get_document(uri)
    end

    def self.get_document(uri)
      response = Net::HTTP.get(URI.parse(uri))
      doc = REXML::Document.new(response)
    end
  end

  def self.total_route_distance
    farthest_east, farthest_west = Location.new({:address => "", :lng => -180.0}), Location.new({:address => "", :lng => 0.0})

    @states.each do |state|
      hops = Location.find_all(state)
      hops.each do |hop|
        farthest_east = hop if(hop.is_farther_east_than(farthest_east))
        farthest_west = hop if(hop.is_farther_west_than(farthest_west))
      end
    end
    farthest_east.distance_between(farthest_west)
  end
  
end

puts "The total distance of the Ride4Ruby is #{Ride4Ruby.total_route_distance}"