#!/usr/bin/env ruby

require 'redis'
require 'json'
require 'yaml'
require 'optparse'
require 'ostruct'
require 'flapjack/data/entity_check'

options = OpenStruct.new
options.config    = File.join('etc', 'flapjack_config.yaml')
options.daemonize = nil

OptionParser.new do |opts|
  opts.banner = "Usage: flapjack-nagios-receiver [options]"

  opts.on("-c", "--config [PATH]", String, "PATH to the config file to use") do |c|
    options.config = c
  end

  opts.on("-f", "--fifo FIFO", String, "Path to the nagios perfdata named pipe") do |f|
    options.fifo = f
  end

end.parse!(ARGV)

FLAPJACK_ENV = ENV['FLAPJACK_ENV'] || 'development'

# load the config hash for the current environment

if File.file?(options.config)
  config = YAML::load(File.open(options.config))
else
  puts "Could not find config file at '#{options.config}', you may want to specify one with the --config option"
  exit(false)
end

config_env = config[FLAPJACK_ENV]

if config_env.nil? || config_env.empty?
  puts "No config data for environment '#{FLAPJACK_ENV}' found in '#{options.config}'"
  exit(false)
end

if !options.fifo
  puts "You must specify a path to the nagios perfdata named pipe using the --fifo option"
  exit(false)
end

@fifo = File.new(options.fifo)

# nagios.cfg contains the following templates for host and service data (modified from the default
# to include hoststate / servicestate, and a fake service 'HOST' for hostperfdata, so that the
# fields match up
# host_perfdata_file_template=[HOSTPERFDATA]\t$TIMET$\t$HOSTNAME$\tHOST\t$HOSTSTATE$\t$HOSTEXECUTIONTIME$\t$HOSTLATENCY$\t$HOSTOUTPUT$\t$HOSTPERFDATA$
# service_perfdata_file_template=[SERVICEPERFDATA]\t$TIMET$\t$HOSTNAME$\t$SERVICEDESC$\t$SERVICESTATE$\t$SERVICEEXECUTIONTIME$\t$SERVICELATENCY$\t$SERVICEOUTPUT$\t$SERVICEPERFDATA$

@redis_host     = config_env['redis']['host'] || 'localhost'
@redis_port     = config_env['redis']['port'] || '6379'
@redis_path     = config_env['redis']['path'] || nil
@redis_db       = config_env['redis']['db']   || 0

if config_env.nil? || config_env.empty?
  puts "No config data for environment '#{FLAPJACK_ENV}'"
  exit(false)
end

def process_input

  if @redis_path
    redis = Redis.new(:db => @redis_db, :path => @redis_path)
  else
    redis = Redis.new(:db => @redis_db, :host => @redis_host, :port => @redis_port)
  end

  begin
    while line = @fifo.gets
      skip unless line
      object_type, timestamp, entity, check, state, check_time, check_latency, check_output, check_perfdata = line.split("\t")
      puts "#{object_type}, #{timestamp}, #{entity}, #{check}, #{state}, #{check_output}"
      next unless line.length == 9
      next unless timestamp =~ /^\d+$/
      next unless (object_type == '[HOSTPERFDATA]') or (object_type == '[SERVICEPERFDATA]')
      state = 'ok'       if state.downcase == 'up'
      state = 'critical' if state.downcase == 'down'
      event = {
        'entity'    => entity,
        'check'     => check,
        'type'      => 'service',
        'state'     => state,
        'summary'   => check_output,
        'timestamp' => timestamp,
      }.to_json
      redis.rpush 'events', event
    end
  rescue Redis::CannotConnectError
    puts "Error, unable to to connect to the redis server (#{$!})"
  rescue EOFError
    puts "Error - end of file reached when reading from the named pipe. Nagios down?"
    sleep 10
  end
end

def main
  while true
    process_input
    sleep 10
  end
end

main