#!/usr/bin/env ruby
require 'rubygems'
require 'active_support/core_ext/numeric/time'
require 'getoptlong'
require 'mysql2'
require 'yaml'
require 'time'

# The name of the plugin. Make it meaningfull
PLUGIN_NAME = 'hours_since_db_backup'
BACKUP_LOG_DATABASE_CONFIG = "/opt/sage/phpmyadmin/database.yml"

def usage
  puts("#{$0} -h <host_id> [-i <sampling_interval>]")
  exit
end

def main
  # Sync stdout so that it will flush to collectd properly
  $stdout.sync = true

  # parse command line options
  hostname = nil
  sampling_interval = 60 # Sec, default value
  opts = GetoptLong.new(
    [ '--hostid', '-h', GetoptLong::REQUIRED_ARGUMENT],
    [ '--sampling-interval', '-i', GetoptLong::OPTIONAL_ARGUMENT]
  )

  opts.each do |opt, arg|
    case opt
      when '--hostid'
        hostname = arg
      when '--sampling-interval'
        sampling_interval = arg.to_i
    end
  end
  usage if !hostname

  create_connection_to_local_database

  # Collection loop
  while true do
    begin
      start_run = Time.now.to_i
      next_run = start_run + sampling_interval

      result = nil
      hosts = []

      # get all hosts
      result = @database_backups.query("select host_dns_name from host_backup_schedule group by host_dns_name;")
      result.each do |row|
        hosts << "#{row["host_dns_name"]}"
      end

      # for each host
      hosts.each do |host|
        query = "SELECT host_dns_name, last_backup_time FROM host_backup_schedule WHERE host_dns_name = '#{host}' AND last_result = 'SUCCESS' ORDER BY last_backup_time Desc limit 1;"
        result = @database_backups.query(query)

        result.each do |row|
          # The sketchy data seems to reject graphnames (gauge-#{host_dns_name}) longer than ~ 60 characters
          host_dns_name = host.gsub('.','_')[0..55]
          last_backup_time = row["last_backup_time"]
          hours_since_last_backup = ((Time.now - last_backup_time) / 1.hour).round(2)
          puts "PUTVAL #{hostname}/#{PLUGIN_NAME}/gauge-#{host_dns_name} interval=#{sampling_interval} #{start_run}:#{hours_since_last_backup}"
        end
      end

      # sleep to make the interval
      while((time_left = (next_run - Time.now.to_i)) > 0) do
        sleep(time_left)
      end

    rescue Exception
      STDERR.puts "Failed to run health check: #{$!}"
      log("Failed to run health check: #{$!}")
      puts("PUTVAL #{hostname}/#{PLUGIN_NAME}/gauge-response_code #{start_run}:99999")

      # sleep to make the interval
      while((time_left = (next_run - Time.now.to_i)) > 0) do
        sleep(time_left)
      end
    end
  end
end

# Creates aconnection to access local database-backups database
def create_connection_to_local_database
  app_config = YAML.load_file(BACKUP_LOG_DATABASE_CONFIG)
  host = app_config["host"]
  username = app_config["username"]
  password = app_config["password"] || ""
  @database_backups = Mysql2::Client.new(:host => "#{host}",
                                         :username => "#{username}",
                                         :password => "#{password}",
                                         :database => "database_backups")
rescue => e
  puts e.message
end