require 'ostruct'

module Rack
  class GeoLocale
    def initialize(app)
      @app = app

      @geoip = GeoIP.new(ENV["GEOIP_DATABASE"])
    end

    def call(env)
      env["locale.country"] = parse_country(env)
      env["locale.languages"] = parse_languages(env)

      @app.call(env)
    end

    private
      def parse_country(env)
        remote_addr = env["REMOTE_ADDR"]

        return nil unless remote_addr

        result = @geoip.country(remote_addr).country_code2

        if result != "--"
          result
        else
          nil
        end
      end

      def parse_languages(env)
        env["HTTP_ACCEPT_LANGUAGE"] ||= ""
        language_ranges = env["HTTP_ACCEPT_LANGUAGE"].split(",")
        language_ranges.map do |language_range|
          language_range += ';q=1.0' unless language_range =~ /;q=\d+\.\d+$/

          locale, q = language_range.split(";q=")

          language = locale.strip.split("-").first

          {:language => language, :q => q}
        end.sort {|x, y| y[:q] <=> x[:q]}.map{|lr| lr[:language]}
      end
  end
end