#!/usr/bin/ruby
#
#  This script will pull tests to complete from the Beanstalk Queue,
# where they will be found in JSON form, and executes them.
#
#
#  TODO: Command line parsing:
#
#           1.  enable/disable logging to a file
#
#
#
# Steve
# --
#



require 'beanstalk-client'
require 'getoptlong'
require 'json'

require 'mauve/sender'
require 'mauve/proto'



#
# Implementation of our protocol tests.
#
require 'tests/ftp'
require 'tests/http'
require 'tests/https'
require 'tests/jabber'
require 'tests/ldap'
require 'tests/ping'
require 'tests/rsync'
require 'tests/smtp'
require 'tests/ssh'




#
#  This class encapsulates the raising and clearing of alerts via Mauve.
#
class Alert

  attr_reader :details

  def initialize( test_details )
    @details = test_details
  end


  #
  # Raise the alert.
  #
  def raise

    update = Mauve::Proto::AlertUpdate.new
    update.alert   = []
    update.source  = "custodian"
    update.replace = true

    alert            = Mauve::Proto::Alert.new
    alert.id         = @details['test_type']
    alert.subject    = "#{@details['test_host']} #{@details['test_alert']]"
    alert.detail     = "The test of type #{@details['test_type']} failed"
    alert.raise_time = Time.now.to_i
    update.alert << alert

    Mauve::Sender.new("alert.bytemark.co.uk").send(update)

  end

  #
  #  Clear the alert.
  #
  def clear
    update = Mauve::Proto::AlertUpdate.new
    update.alert   = []
    update.source  = "custodian"
    update.replace = true

    alert            = Mauve::Proto::Alert.new
    alert.id         = @details['test_type']
    alert.subject    = "#{@details['test_host']} #{@details['test_alert']]"
    alert.detail     = "The test of type #{@details['test_type']} failed"
    alert.clear_time = Time.now.to_i
    update.alert << alert

    Mauve::Sender.new("alert.bytemark.co.uk").send(update)
  end

end



#
# This class contains the code for connecting to a Beanstalk queue,
# fetching tests from it, and executing them
#
class Custodian

  #
  # The beanstalk queue.
  #
  attr_reader :queue

  #
  # How many times we re-test before we detect a failure
  #
  attr_reader :retry_count

  #
  # Constructor: Connect to the queue
  #
  def initialize( server )
    @queue = Beanstalk::Pool.new([server])

    if ( ENV['REPEAT'] )
       @retry_count=ENV['REPEAT'].to_i
    else
       @retry_count=5
    end

    puts "Retrying each test #{@retry_count} times before failures" if ( ENV['VERBOSE'] )
  end


  #
  #  Flush the queue.
  #
  def flush_queue!
    while( true )
      begin
        job = @queue.reserve(1)
        id  = job.id
        puts "\tDeleted job #{id}" if ( ENV['VERBOSE'] )
        job.delete
      rescue Beanstalk::TimedOut => ex
        return
      end
    end
  end

  #
  # Process jobs from the queue - never return.
  #
  def run!
    while( true )
      puts "\n\nWaiting for job.." if ( ENV['VERBOSE'] )
      process_single_job()
    end
  end


  #
  # Fetch a single job from the queue, and process it.
  #
  def process_single_job

    begin
      job = @queue.reserve()
      puts "Job acquired: #{Time.new.inspect}" if ( ENV['VERBOSE'] )


      #
      #  Parse the JSON of the job body.
      #
      json = job.body
      hash = JSON.parse( json )
      hash['verbose'] = 1 if ( ENV['VERBOSE'] )


      #
      #  Output the details.
      #
      if ( ENV['VERBOSE'] )
        puts "JOB: #{job.id}"
        puts "Type of test is #{hash['test_type']}"
        hash.keys.each do |key|
          puts "\t#{key} => #{hash[key]}"
        end
      end


      #
      #  Given the test-type of "YYY" we'll call the method "YYY_test", which
      # we assume comes from one of the files beneath ./tests/
      #
      test   = hash['test_type']
      method = "#{test}_test".to_sym

      #
      # Did the test succeed?  If not count the number of times it failed in
      # a row.  We'll repeat several times
      #
      success = false
      count   = 0

      #
      # As a result of this test we'll either raise/clear with mauve.
      #
      # This helper will do that job.
      #
      alert = Alert.new( hash )

      #
      #  We'll run no more than MAX times.
      #
      #  We stop the execution on a single success.
      #
      while ( ( count < @retry_count ) && ( success == false ) )
        if ( send( method, hash ) )
          alert.clear()
          success= true
        end
        count += 1
      end

      #
      #  If we didn't succeed on any of the attempts raise the alert.
      #
      if ( ! success )
        alert.raise()
      end
    rescue => ex
      puts "Exception raised processing job: #{ex}"
    ensure
      #
      #  Delete the job - either we received an error, in which case
      # we should remove it to avoid picking it up again, or we handled
      # it successfully so it should be removed.
      #
      job.delete
    end
  end
end







#
#  Entry-point to our code.
#
if __FILE__ == $0 then

  $SERVER = "127.0.0.1:11300";

  begin
    opts = GetoptLong.new(
                          [ "--verbose", "-v", GetoptLong::NO_ARGUMENT ],
                          [ "--flush",   "-f", GetoptLong::NO_ARGUMENT ],
                          [ "--server",  "-S", GetoptLong::REQUIRED_ARGUMENT ],
                          [ "--repeat",  "-r", GetoptLong::REQUIRED_ARGUMENT ],
                          [ "--single",  "-s", GetoptLong::NO_ARGUMENT ]
                          )
    opts.each do |opt, arg|
      case opt
      when "--verbose":
          ENV["VERBOSE"] = "1"
      when "--flush":
          ENV["FLUSH"] = "1"
      when "--repeat":
          ENV["REPEAT"] = arg
      when "--server":
          ENV["SERVER"] = arg
      when "--single":
          ENV["SINGLE"] = "1"
      end
    end
  rescue StandardError => ex
    puts "Option parsing failed: #{ex.to_s}"
    exit
  end

  #
  #  Create the object
  #
  worker = Custodian.new( $SERVER )

  #
  #  Are we flushing the queue?
  #
  if ( ENV['FLUSH'] )
    worker.flush_queue!
    exit(0)
  end

  #
  #  Single step?
  #
  if ( ENV['SINGLE'] )
    worker.process_single_job
    exit(0)
  end

  #
  #  Otherwise loop indefinitely
  #
  worker.run!
end