http__superhub

#!/usr/bin/env ruby

if $0 =~ /^(?:|.*\/)http_([^_]+)_/
  host = $1
end
abort "# Error: couldn't understand what I'm supposed to monitor." unless host

require 'net/http'
require 'nokogiri'

class SuperhubStats

  def initialize(host)
    @host = host
  end

  def downstream_channel_details
    cells = get_table_data(downstream_stats_page, 'Downstream')
    rows = cells.each_with_object({}) do |row, result|
      result[row[0]] = row[1..-1]
    end
    8.times.map do |n|
      {
        :lock_status => rows["Lock Status(QAM Lock/FEC Sync/MPEG Lock)"][n],
        :rx_power => rows["Power Level (dBmV)"][n],
        :snr => rows["RxMER (dB)"][n],
      }
    end
  end

  def upstream_channel_details
    cells = get_table_data(upstream_stats_page, 'Upstream')
    rows = cells.each_with_object({}) do |row, result|
      result[row[0]] = row[1..-1]
    end
    4.times.map do |n|
      {
        :lock_status => rows["Ranging Status"][n],
        :tx_power => rows["Power Level (dBmV)"][n],
      }
    end
  end

  private

  def downstream_stats_page
    @downstream_stats_page ||= Nokogiri::HTML(get_downstream_stats_page)
  end

  def upstream_stats_page
    @upstream_stats_page ||= Nokogiri::HTML(get_upstream_stats_page)
  end

  def get_table(doc, caption)
    doc.at_xpath("//table[.//caption[contains(., '#{caption}')]]")
  end

  def get_table_data(doc, caption)
    table = get_table(doc, caption)
    table.css('tr').map do |row|
      row.css('th, td').map do |cell|
        cell.text
      end
    end
  end

  def get_downstream_stats_page
    get_page('/VmRouterStatus_downstream.asp')
  end

  def get_upstream_stats_page
    get_page('/VmRouterStatus_upstream.asp')
  end

  def get_page(path)
    Net::HTTP.get(@host, path)
  end
end

if (ARGV[0] == 'config')
  puts "host_name #{host}" unless host == 'localhost'

  puts <<-EOT
multigraph locked_channels
graph_title Locked channels
graph_category network
graph_args -l 0
downstream.label Downstream
downstream.draw LINE1
upstream.label Upstream
upstream.draw LINE1
  EOT

  puts <<-EOT
multigraph downstream_snr
graph_title Downstream SNR
graph_category network
graph_vlabel dB
  EOT
  8.times do |i|
    i += 1
    puts "ch#{i}.label Channel #{i}"
    puts "ch#{i}.draw LINE1"
  end

  puts <<-EOT
multigraph power_levels
graph_title Power Levels
graph_category network
graph_vlabel dBmV
  EOT
  8.times do |i|
    i += 1
    puts "rx#{i}.label RX Ch #{i}"
    puts "rx#{i}.draw LINE1"
  end
  4.times do |i|
    i += 1
    puts "tx#{i}.label TX Ch #{i}"
    puts "tx#{i}.draw LINE1"
  end

  exit 0
end

def strip_units(value)
  value.gsub(/[^0-9.-]/, '')
end

stats = SuperhubStats.new(host)

downstream_details = stats.downstream_channel_details
upstream_details = stats.upstream_channel_details

puts "multigraph locked_channels"
puts "downstream.value #{downstream_details.select {|ch| ch[:lock_status] == "Locked"}.size}"
puts "upstream.value #{upstream_details.select {|ch| ch[:lock_status] == "Success"}.size}"

puts "multigraph downstream_snr"
downstream_details.each_with_index do |ch, i|
  i += 1
  if ch[:lock_status] == "Locked"
    puts "ch#{i}.value #{strip_units(ch[:snr])}"
  else
    puts "ch#{i}.value U"
  end
end

puts "multigraph power_levels"
downstream_details.each_with_index do |ch, i|
  i += 1
  if ch[:lock_status] == "Locked"
    puts "rx#{i}.value #{strip_units(ch[:rx_power])}"
  else
    puts "rx#{i}.value U"
  end
end
upstream_details.each_with_index do |ch, i|
  i += 1
  if ch[:lock_status] == "Success"
    puts "tx#{i}.value #{strip_units(ch[:tx_power])}"
  else
    puts "tx#{i}.value U"
  end
end