module Geocoder
  module Store
    module Base

      ##
      # Is this object geocoded? (Does it have latitude and longitude?)
      #
      def geocoded?
        to_coordinates.compact.size > 0
      end

      ##
      # Coordinates [lat,lon] of the object.
      #
      def to_coordinates
        [:latitude, :longitude].map{ |i| send self.class.geocoder_options[i] }
      end

      ##
      # Calculate the distance from the object to an arbitrary point.
      # See Geocoder::Calculations.distance_between for ways of specifying
      # the point. Also takes a symbol specifying the units
      # (:mi or :km; can be specified in Geocoder configuration).
      #
      def distance_to(point, units = nil)
        units ||= self.class.geocoder_options[:units]
        return nil unless geocoded?
        Geocoder::Calculations.distance_between(
          to_coordinates, point, :units => units)
      end

      alias_method :distance_from, :distance_to

      ##
      # Calculate the bearing from the object to another point.
      # See Geocoder::Calculations.distance_between for
      # ways of specifying the point.
      #
      def bearing_to(point, options = {})
        options[:method] ||= self.class.geocoder_options[:method]
        return nil unless geocoded?
        Geocoder::Calculations.bearing_between(
          to_coordinates, point, options)
      end

      ##
      # Calculate the bearing from another point to the object.
      # See Geocoder::Calculations.distance_between for
      # ways of specifying the point.
      #
      def bearing_from(point, options = {})
        options[:method] ||= self.class.geocoder_options[:method]
        return nil unless geocoded?
        Geocoder::Calculations.bearing_between(
          point, to_coordinates, options)
      end

      ##
      # Get nearby geocoded objects.
      # Takes the same options hash as the near class method (scope).
      # Returns nil if the object is not geocoded.
      #
      def nearbys(radius = 20, options = {})
        return nil unless geocoded?
        options.merge!(:exclude => self) unless send(self.class.primary_key).nil?
        self.class.near(self, radius, options)
      end

      ##
      # Look up coordinates and assign to +latitude+ and +longitude+ attributes
      # (or other as specified in +geocoded_by+). Returns coordinates (array).
      #
      def geocode
        fail
      end

      ##
      # Look up address and assign to +address+ attribute (or other as specified
      # in +reverse_geocoded_by+). Returns address (string).
      #
      def reverse_geocode
        fail
      end

      private # --------------------------------------------------------------

      ##
      # Look up geographic data based on object attributes (configured in
      # geocoded_by or reverse_geocoded_by) and handle the results with the
      # block (given to geocoded_by or reverse_geocoded_by). The block is
      # given two-arguments: the object being geocoded and an array of
      # Geocoder::Result objects).
      #
      def do_lookup(reverse = false)
        options = self.class.geocoder_options
        if reverse and options[:reverse_geocode]
          query = to_coordinates
        elsif !reverse and options[:geocode]
          query = send(options[:user_address])
        else
          return
        end

        query_options = [:lookup, :ip_lookup, :language].inject({}) do |hash, key|
          if options.has_key?(key)
            val = options[key]
            hash[key] = val.respond_to?(:call) ? val.call(self) : val
          end
          hash
        end
        results = Geocoder.search(query, query_options)

        # execute custom block, if specified in configuration
        block_key = reverse ? :reverse_block : :geocode_block
        if custom_block = options[block_key]
          custom_block.call(self, results)

        # else execute block passed directly to this method,
        # which generally performs the "auto-assigns"
        elsif block_given?
          yield(self, results)
        end
      end
    end
  end
end