module RGeoServer
  # A layer group is a grouping of layers and styles that can be accessed as a single layer in a WMS GetMap request. A Layer group is often referred to as a "base map".
  class LayerGroup < ResourceInfo

    OBJ_ATTRIBUTES = {:catalog => 'catalog', :name => 'name', :layers => 'layers', :styles => 'styles', :bounds => 'bounds', :metadata => 'metadata' }
    OBJ_DEFAULT_ATTRIBUTES = {:catalog => nil, :name => nil, :layers => [], :styles => [], :bounds => {'minx'=>'', 'miny' =>'', 'maxx'=>'', 'maxy'=>'', 'crs' =>''}, :metadata => {} }

    define_attribute_methods OBJ_ATTRIBUTES.keys
    update_attribute_accessors OBJ_ATTRIBUTES

    @@route = "layergroups" 
    @@resource_name = "layerGroup"

    def self.resource_name
      @@resource_name
    end

    def self.root_xpath
      "//#{@@route}/#{@@resource_name}"
    end

    def self.member_xpath
      "//#{resource_name}"
    end

    def route
      @@route  
    end

    def message
      builder = Nokogiri::XML::Builder.new do |xml|
        xml.layerGroup { 
          xml.name @name
          xml.layers {
            layers.each { |l| 
              xml.layer {
                xml.name l.name
              }
            }
          } unless layers.nil?
          xml.styles {
            styles.each { |s|
              xml.style {
                xml.name s.name
              }
            }
          } unless styles.nil?
          xml.bounds {
            xml.minx bounds['minx']
            xml.maxx bounds['maxx']
            xml.miny bounds['miny']
            xml.maxy bounds['maxy']
            xml.crs bounds['crs']
          } if @bounds
        }
      end
      return builder.doc.to_xml 
    end

    # @param [RGeoServer::Catalog] catalog
    # @param [Hash] options
    # @option options [String] :name
    def initialize catalog, options
      super({})
      _run_initialize_callbacks do
        @catalog = catalog
        @name = options[:name].strip
      end        
      @route = route
    end
    
    # @param [Array<RGeoServer::Style>] sl list of styles
    def styles= sl
      if sl.inject(true){|t,s| t && s.is_a?(RGeoServer::Style)}
        styles_will_change! unless sl == styles
        @styles = sl
      else
        raise 'Unknown list of styles'
      end
    end
    
    def styles
      @styles ||= begin
        unless profile['styles'].empty?
          return profile['styles'].each{ |s| RGeoServer::Style.new @catalog, :name => s.name }
        else
          nil
        end
      rescue Exception => e
        nil
      end
    end

    # @param [Array<RGeoServer::Layer>] ll list of layers
    def layers= ll
      if ll.inject(true){ |t,l| t && l.is_a?(RGeoServer::Layer) }
        layers_will_change! unless ll == layers
        @layers = ll
      else
        raise 'Unknown list of layers'
      end
    end
    
    def layers
      @layers ||= begin
        unless profile['layers'].empty?
          return profile['layers'].each{ |s| RGeoServer::Layer.new @catalog, :name => s.name }
        else
          nil
        end
      rescue Exception => e
        nil
      end
    end

    def profile_xml_to_hash profile_xml
      doc = profile_xml_to_ng profile_xml
      name = doc.at_xpath('//name/text()').to_s

      h = {
        "name" => name, 
        "layers" => doc.xpath('//layers/layer/name/text()').collect{|l| l.to_s},
        "styles" => doc.xpath('//styles/style/name/text()').collect{|s| s.to_s},
        "bounds" => { 
          "minx" => doc.at_xpath('//bounds/minx/text()').to_s,
          "maxx" => doc.at_xpath('//bounds/maxx/text()').to_s,
          "miny" => doc.at_xpath('//bounds/miny/text()').to_s,
          "maxy" => doc.at_xpath('//bounds/maxy/text()').to_s,
          "crs" => doc.at_xpath('//bounds/crs/text()')
        },
        "metadata" => doc.xpath('//metadata/entry').inject({}){ |h, e| h.merge(e['key']=> e.text.to_s) } 
      }.freeze
      h  
    end

  end
end