require 'geo_ruby/simple_features/geometry_collection'

module GeoRuby

  module SimpleFeatures

    #Represents a group of polygons (see Polygon).
    class MultiPolygon < GeometryCollection

      def initialize(srid = DEFAULT_SRID,with_z=false,with_m=false)
        super(srid)
      end

      def binary_geometry_type #:nodoc:
        6
      end

      def points
        @points ||= geometries.inject([]) do |arr, r|
          arr.concat(r.rings.map(&:points).flatten)
        end
      end

      #Text representation of a MultiPolygon
      def text_representation(allow_z=true,allow_m=true) #:nodoc:
        @geometries.map {|polygon| "(" + polygon.text_representation(allow_z,allow_m) + ")"}.join(",")
      end

      #WKT geometry type
      def text_geometry_type #:nodoc:
        "MULTIPOLYGON"
      end

      def to_coordinates
        geometries.map{|polygon| polygon.to_coordinates}
      end

      def as_json(options = {})
        {:type => 'MultiPolygon',
         :coordinates => self.to_coordinates}
      end

      # simple geojson representation
      # TODO add CRS / SRID support?
      def to_json(options = {})
        as_json(options).to_json(options)
      end
      alias :as_geojson :to_json

      #Creates a multi polygon from an array of polygons
      def self.from_polygons(polygons,srid=DEFAULT_SRID,with_z=false,with_m=false)
        multi_polygon = new(srid,with_z,with_m)
        multi_polygon.concat(polygons)
        multi_polygon
      end

      #Creates a multi polygon from sequences of points : ((((x,y)...(x,y)),((x,y)...(x,y)),((x,y)...(x,y)))
      def self.from_coordinates(point_sequence_sequences,srid= DEFAULT_SRID,with_z=false,with_m=false)
        multi_polygon = new(srid,with_z,with_m)
        multi_polygon.concat( point_sequence_sequences.collect {|point_sequences| Polygon.from_coordinates(point_sequences,srid,with_z,with_m) } )
        multi_polygon
      end

    end

  end

end