module CartoJson
  class LineString
    include Shape
    type :linestring

    attr_accessor :points

    def initialize(input)
      super
      @points = []
      input[:points].each do |p|
        if p.is_a?(Point)
          @points << p
        else
          @points << Point.new(LAT => p[LAT], LNG => p[LNG])
        end
      end

      validate
    end

    def to_hash
      {:type   => self.class.type,
       :points => points.collect {|p| p.to_hash_for_array}}
    end

    def to_wkt
      "#{type.to_s.upcase} ((#{@points.dup.push(@points.first).collect {|p| "#{p.send(LNG)} #{p.send(LAT)}"}.join(', ')}))"
    end

    protected

    def validate
      if @points.length < 2
        raise InsufficientPointsError, "a minimum of 2 points is required to make a linestring, you provided #{@points.length}"
      end
    end
  end
end