require "nasa_rovers/coord"

module NasaRovers
  class Position
    class CardinalError < StandardError; end

    def self.factory(data)
      new(*data.split(" "))
    end

    attr_reader :coord
    attr_accessor :cardinal

    def initialize(x, y, cardinal, coord_class=Coord)
      @coord = coord_class.new(x, y)
      @cardinal = check(cardinal)
    end

    def to_s
      "#{coord} #{cardinal}"
    end

    def ==(other)
      coord == other.coord && cardinal == other.cardinal
    end

    private def check(cardinal)
      return cardinal if CARDINALS.include?(cardinal)
      fail CardinalError.new("#{cardinal} is not a valid cardinal point")
    end
  end
end