require 'core_ext/module/monitor'
require 'facets/module/alias_method_chain' unless Module.methods.include?(:alias_method_chain)
require 'facets/string/snakecase'

module Fozzie
  module Sniff

    def _monitor(bucket_name = nil)
      @_monitor_flag = true
      @_bucket_name  = bucket_name
    end

    def _monitor_meth(target, &blk)
      return if @_monitor_flag.nil? || !@_monitor_flag

      @_monitor_flag = false
      bin            = @_bucket_name || [self.name.snakecase, target.to_s.snakecase]
      feature        = :monitor
      aliased_target = target.to_s.sub(/([?!=])$/, '')
      punctuation    = $1

      with    = "#{aliased_target}_with_#{feature}#{punctuation}"
      without = "#{aliased_target}_without_#{feature}#{punctuation}"

      blk.call(with, without, feature, bin)
    end

    def method_added(target)
      _monitor_meth(target) do |with, without, feature, bin|
        define_method(with) do |*args, &blk|
          S.time_for(bin) do
            args.empty? ? self.send(without, &blk) : self.send(without, *args, &blk)
          end
        end
        self.alias_method_chain(target, feature)
      end
    end

    def singleton_method_added(target)
      _monitor_meth(target) do |with, without, feature, bin|
        define_singleton_method(with) do |*args, &blk|
          S.time_for(bin) do
            args.empty? ? send(without, &blk) : send(without, *args, &blk)
          end
        end
        self.singleton_class.class_eval { alias_method_chain target, feature }
      end
    end

  end

end