require "method_watcher/version"

module MethodWatcher
  class << self
    def included mod
      mod.instance_variable_set "@_watch_methods", {}
      mod.singleton_class.class_eval do
        def watch_methods *methods
          methods.each do |method|
            watch_method method
          end
        end

        def watch_method method
          @_watch_methods[method.to_sym] = self
        end

        def method_added method
          super
          if @_watch_methods.has_key?(method.to_sym)
            @_watch_methods[method].method_overriding method
          end
        end

        def method_overriding method
          warn "method #{self}##{method} is overridden"
        end


        def inherited mod
          super
          super_watch_methods = (mod.respond_to?(:superclass) && mod.superclass && mod.superclass.instance_variable_get("@_watch_methods")) || {}
          mod.instance_variable_set "@_watch_methods", super_watch_methods.merge({})
        end
      end
    end
  end
end