Ohai.plugin(:Hardware) do
  provides "hardware"

  def read_sysctl_link(file)
    File.basename(File.readlink(file))
  rescue Errno::ENOENT
  end

  def read_sysctl_file(file)
    IO.read(file).strip
  rescue Errno::ENOENT, Errno::EINVAL
  end

  def pci_devices
    device = nil

    IO.popen(["lspci", "-Dkvmm"]).each_with_object(Mash.new) do |line, devices|
      if line =~ /^Slot:\s+((\h{4}):(\h{2}):(\h{2}).(\h))\s*$/
        device = {
          :slot => Regexp.last_match(1),
          :domain => Regexp.last_match(2),
          :bus => Regexp.last_match(3),
          :device => Regexp.last_match(4),
          :function => Regexp.last_match(5)
        }
      elsif device && line =~ /^([A-Z]+):\s+(.*)\s*$/i
        case Regexp.last_match(1)
        when "Class" then device[:class_name] = Regexp.last_match(2)
        when "Vendor" then device[:vendor_name] = Regexp.last_match(2)
        when "Device" then device[:device_name] = Regexp.last_match(2)
        when "SVendor" then device[:subsystem_vendor_name] = Regexp.last_match(2)
        when "SDevice" then device[:subsystem_device_name] = Regexp.last_match(2)
        when "PhySlot" then device[:physical_slot] = Regexp.last_match(2)
        when "Rev" then device[:revision] = Regexp.last_match(2)
        when "ProgIf" then device[:programming_interface] = Regexp.last_match(2)
        when "Driver" then device[:driver] = Regexp.last_match(2)
        when "Module" then device[:modules] = Array(device[:modules]) << Regexp.last_match(2)
        end
      elsif device && line =~ /^\s*$/
        devices[device[:slot]] = device
        device = nil
      end
    end
  end

  def network_devices
    Dir.glob("/sys/class/net/*").each_with_object(Mash.new) do |device, devices|
      name = File.basename(device)

      devices[name] = {
        :device => read_sysctl_link("#{device}/device"),
        :duplex => read_sysctl_file("#{device}/duplex"),
        :speed => read_sysctl_file("#{device}/speed")
      }.delete_if { |_, v| v.nil? }
    end
  end

  def memory_devices
    device = nil

    IO.popen(["dmidecode", "-t", "memory"]).each_with_object([]) do |line, devices|
      if line =~ /^Memory Device\s*$/
        device = {}
      elsif device && line =~ /^\s+([A-Z ]+):\s+(.*)\s*$/i
        device[Regexp.last_match(1).tr(" ", "_").downcase.to_sym] = Regexp.last_match(2).strip
      elsif device && line =~ /^\s*$/
        devices << device
        device = nil
      end
    end
  end

  collect_data(:default) do
    hardware Mash.new

    hardware[:pci] = pci_devices
    hardware[:network] = network_devices
    hardware[:memory] = memory_devices
  end
end