begin
  if RUBY_VERSION == '1.8.7' and !defined?(RUBY_ENGINE)
    require 'flay'
    require 'yaml'

    config      = YAML.load_file(File.expand_path('../../../config/flay.yml', __FILE__)).freeze
    threshold   = config.fetch('threshold').to_i
    total_score = config.fetch('total_score').to_f
    files       = Flay.expand_dirs_to_files(config.fetch('path', 'lib'))

    # original code by Marty Andrews:
    # http://blog.martyandrews.net/2009/05/enforcing-ruby-code-quality.html
    desc 'Analyze for code duplication'
    task :flay do
      # run flay once without a threshold to ensure the max mass matches the threshold
      flay = Flay.new(:fuzzy => false, :verbose => false, :mass => 0)
      flay.process(*files)

      max = flay.masses.map { |hash, mass| mass.to_f / flay.hashes[hash].size }.max
      unless max >= threshold
        raise "Adjust flay threshold down to #{max}"
      end

      total = flay.masses.reduce(0.0) { |total, (hash, mass)| total + (mass.to_f / flay.hashes[hash].size) }
      unless total == total_score
        raise "Flay total is now #{total}, but expected #{total_score}"
      end

      # run flay a second time with the threshold set
      flay = Flay.new(:fuzzy => false, :verbose => false, :mass => threshold.succ)
      flay.process(*files)

      if flay.masses.any?
        flay.report
        raise "#{flay.masses.size} chunks of code have a duplicate mass > #{threshold}"
      end
    end
  else
    task :flay do
      $stderr.puts 'Flay has inconsistend results accros ruby implementations. It is only enabled on 1.8.7, fix and remove guard'
    end
  end
rescue LoadError
  task :flay do
    abort 'Flay is not available. In order to run flay, you must: gem install flay'
  end
end