module Tins::DateTimeDummy

def self.included(modul)
  class << modul
    alias really_now now
    remove_method :now rescue nil
    def dummy=(value)
      if value.respond_to?(:to_str)
        value = DateTime.parse(value.to_str)
      elsif value.respond_to?(:to_datetime)
        value = value.to_datetime
      end
      @dummy = value
    end
    def dummy(value = nil)
      if value.nil?
        @dummy
      else
        begin
          old_dummy = @dummy
          self.dummy = value
          yield
        ensure
          self.dummy = old_dummy
        end
      end
    end
    def now
      if dummy
        dummy.dup
      elsif caller.first =~ /`now`/
        really_now
      else
        really_now
      end
    end
  end
  super
end

def dummy(value = nil)
  if value.nil?
    @dummy
  else
    begin
      old_dummy = @dummy
      self.dummy = value
      yield
    ensure
      self.dummy = old_dummy
    end
  end
end

def dummy=(value)
  if value.respond_to?(:to_str)
    value = DateTime.parse(value.to_str)
  elsif value.respond_to?(:to_datetime)
    value = value.to_datetime
  end
  @dummy = value
end

def now
  if dummy
    dummy.dup
  elsif caller.first =~ /`now`/
    really_now
  else
    really_now
  end
end