require "lvm/wrapper"
require "lvm/volume_group"

module LVM
  module Wrapper
    class VGS
      include Reporting

      attr_reader :attributes
      attr_reader :command

      def initialize(options)
        @attributes = Attributes.load(options[:version], ATTRIBUTES_FILE)
        @command = "#{options[:command]} #{Reporting.build_command(attributes, BASE_COMMAND, options[:additional_arguments])}"
      end

      BASE_COMMAND = "vgs #{Reporting::BASE_ARGUMENTS}"
      ATTRIBUTES_FILE = "vgs.yaml"

      # vg_attr attribute handling constants
      # roughly by order referenced in lib/report/report.c:360 (_vgstatus_disp)
      #
      PERMISSIONS = {
        "w" => :writeable,
        "r" => :readonly,
      }
      RESIZEABLE = {
        # code says its a boolean
        "z" => true,
      }
      EXPORTED = {
        # code says its a boolean
        "x" => true,
      }
      PARTIAL = {
        # code says its a boolean
        "p" => true,
      }
      ALLOCATION_POLICY = {
        "c" => :contiguous,
        "l" => :cling,
        "n" => :normal,
        "a" => :anywhere,
        "i" => :inherited,
        "C" => :contiguous_locked,
        "L" => :cling_locked,
        "N" => :normal_locked,
        "A" => :anywhere_locked,
        "I" => :inherited_locked,
      }
      CLUSTERED = {
        # code says its a boolean
        "c" => true,
      }

      def list
        output = External.cmd(@command)
        data = parse(output)
        if block_given?
          return data.each { |obj| yield obj }
        else
          return data
        end
      end

      private

      def parse_vg_attr(vg_attr) #:nodoc:
        translated = {}
        # translate them into nice symbols and a couple booleans
        translated[:permissions] = PERMISSIONS[vg_attr[0].chr]
        translated[:resizeable] = RESIZEABLE[vg_attr[1].chr] ? true : false
        translated[:exported] = EXPORTED[vg_attr[2].chr] ? true : false
        translated[:partial] = PARTIAL[vg_attr[3].chr] ? true : false
        translated[:allocation_policy] = ALLOCATION_POLICY[vg_attr[4].chr]
        translated[:clustered] = CLUSTERED[vg_attr[5].chr] ? true : false

        return translated
      end

        # Parses the output of self.command
      def parse(output) #:nodoc:
        volumes = []

        output.split("\n").each do |line|
          args = process_line(attributes, line)

          # now we force some types to ints since we've requested them as bytes
          # without a suffix
          args[:size] = args[:size].to_i

          # we resolve the attributes line to nicer symbols
          args.merge!(parse_vg_attr(args[:attr]))

          # finally build our object
          volume = VolumeGroup.new(args)

          if block_given?
            yield volume
          else
            volumes << volume
          end
        end

        return volumes
      end # parse
    end # class VGS
  end # module Wrapper
end # module LVM