require_relative "../validator"

module GoogleMapsService::Apis
  # Performs requests to the Google Maps Directions API.
  module Directions
    # Get directions between an origin point and a destination point.
    #
    # @example Simple directions
    #   routes = client.directions('Sydney', 'Melbourne')
    #
    # @example Complex bicycling directions
    #   routes = client.directions('Sydney', 'Melbourne',
    #       mode: 'bicycling',
    #       avoid: ['highways', 'tolls', 'ferries'],
    #       units: 'metric',
    #       region: 'au')
    #
    # @example Public transportation directions
    #    an_hour_from_now = Time.now - (1.0/24)
    #    routes = client.directions('Sydney Town Hall', 'Parramatta, NSW',
    #        mode: 'transit',
    #        arrival_time: an_hour_from_now)
    #
    # @example Walking with alternative routes
    #    routes = client.directions('Sydney Town Hall', 'Parramatta, NSW',
    #       mode: 'walking',
    #       alternatives: true)
    #
    # @param [String, Hash, Array] origin The address or latitude/longitude value from which you wish
    #         to calculate directions.
    # @param [String, Hash, Array] destination The address or latitude/longitude value from which
    #     you wish to calculate directions.
    # @param [String] mode Specifies the mode of transport to use when calculating
    #     directions. One of `driving`, `walking`, `bicycling` or `transit`.
    # @param [Array<String>, Array<Hash>, Array<Array>] waypoints Specifies an array of waypoints. Waypoints alter a
    #     route by routing it through the specified location(s).
    # @param [Boolean] alternatives If True, more than one route may be returned in the
    #     response.
    # @param [Array, String] avoid Indicates that the calculated route(s) should avoid the
    #     indicated features.
    # @param [String] language The language in which to return results.
    # @param [String] units Specifies the unit system to use when displaying results.
    #     `metric` or `imperial`.
    # @param [String] region The region code, specified as a ccTLD (_top-level domain_)
    #     two-character value.
    # @param [Integer, DateTime] departure_time Specifies the desired time of departure.
    # @param [Integer, DateTime] arrival_time Specifies the desired time of arrival for transit
    #     directions. Note: you can not specify both `departure_time` and
    #     `arrival_time`.
    # @param [Boolean] optimize_waypoints Optimize the provided route by rearranging the
    #     waypoints in a more efficient order.
    # @param [String, Array<String>] transit_mode Specifies one or more preferred modes of transit.
    #     This parameter may only be specified for requests where the mode is
    #     transit. Valid values are `bus`, `subway`, `train`, `tram` or `rail`.
    #     `rail` is equivalent to `["train", "tram", "subway"]`.
    # @param [String] transit_routing_preference Specifies preferences for transit
    #     requests. Valid values are `less_walking` or `fewer_transfers`.
    #
    # @return [Array] Array of routes.
    def directions(origin, destination,
      mode: nil, waypoints: nil, alternatives: false, avoid: nil,
      language: nil, units: nil, region: nil, departure_time: nil,
      arrival_time: nil, optimize_waypoints: false, transit_mode: nil,
      transit_routing_preference: nil)

      params = {
        origin: GoogleMapsService::Convert.waypoint(origin),
        destination: GoogleMapsService::Convert.waypoint(destination)
      }

      params[:mode] = GoogleMapsService::Validator.travel_mode(mode) if mode

      if waypoints
        waypoints = GoogleMapsService::Convert.as_list(waypoints)
        waypoints = waypoints.map { |waypoint| GoogleMapsService::Convert.waypoint(waypoint) }
        waypoints = ["optimize:true"] + waypoints if optimize_waypoints

        params[:waypoints] = GoogleMapsService::Convert.join_list("|", waypoints)
      end

      params[:alternatives] = "true" if alternatives
      params[:avoid] = GoogleMapsService::Convert.join_list("|", avoid) if avoid
      params[:language] = language if language
      params[:units] = units if units
      params[:region] = region if region
      params[:departure_time] = GoogleMapsService::Convert.time(departure_time) if departure_time
      params[:arrival_time] = GoogleMapsService::Convert.time(arrival_time) if arrival_time

      if departure_time && arrival_time
        raise ArgumentError, "Should not specify both departure_time and arrival_time."
      end

      params[:transit_mode] = GoogleMapsService::Convert.join_list("|", transit_mode) if transit_mode
      params[:transit_routing_preference] = transit_routing_preference if transit_routing_preference

      get("/maps/api/directions/json", params)[:routes]
    end
  end
end