#!/usr/bin/ruby
require 'rubygems'
require 'optparse'
require 'json'

checks  = {}
options = {
  'basedir' => '/etc/nrpe.d',
  'conf_ext' => '.cfg',
}

OptionParser.new do |opts|
  opts.on("-a", "--all")                   { |v| options['all'] = v }
  opts.on("-c", "--command COMMAND")       { |command|  options['command'] = command }
  opts.on("-d", "--directory DIR")         { |dir| options['basedir'] = dir }
  opts.on("-j", "--json")                  { |v| options['json'] = v }
  opts.on("-n", "--name NAME")             { |name| options['name'] = name }
  opts.on("-o", "--output-file FILENAME")  { |filename| options['output'] = filename }
  opts.on("-r", "--return RETCODE")        { |retcode|  options['retcode'] = retcode }
  opts.on("-s", "--summary")               { |v| options['summary'] = v }
end.parse!

# build up the list of checks. Checks that appear more than once
# overwrite the older instance

Dir["#{options['basedir']}/*#{options['conf_ext']}"].each do |file|
  File.open( file, 'r' ).each_line do |line|
    line.chomp!

    next unless line.match(/^command\[(.+)\]=(.+)/)
    name, command = $1, $2

    checks[name] = command
  end
end

# filter out the checks we want to run
#########################

# just in case nothing is filtered.
wanted = checks

if options['name']
  wanted = checks.reject { |k,v| ! k.include? options['name'] }
end

if options['command']
  wanted = checks.reject { |k,v| ! v.include? options['command'] }
end

if options['name'] && options['command']
  wanted = checks.reject { |k,v| (! k.include? options['name']) || (! v.include? options['command']) }
end

details  = { }
statuses = { '0' => 0, '1' => 0, '2' => 0, '3' => 0 }

ran = 0

# run the checks and do some output wrangling
#########################
wanted.each_pair do |name,command|

  output = %x{ #{command} }.chomp!
  ret = $?.to_i / 256 # magic number


  if options['all']
    details[name] = { 'command' => command, 'output' => output, 'returncode' => ret }
  elsif options['retcode']
    if options['retcode'].to_i == ret
      details[name] = { 'command' => command, 'output' => output, 'returncode' => ret }
    end
  else # default to showing everything broken
    if ret != 0
      details[name] = { 'command' => command, 'output' => output, 'returncode' => ret }
    end
  end

  statuses[ret.to_s] += 1
  ran += 1
end

if options['json']
  puts details.to_json
  exit
end

details.keys.each do |name|
  puts "#{name} => #{details[name]['output']}"
end

if options['summary']
  puts "Ran #{ran} checks - OK #{statuses['0']}. WARN #{statuses['1']}, CRIT #{statuses['2']}, UNKNOWN #{statuses['3']}"
end