class Rspec::Core::ExampleGroup

def self.after_ancestors
  @_after_ancestors ||= ancestors(true)
end

def self.alias_example_to(new_alias, extra_options={})
  new_alias = <<-END_RUBY
                def self.#{new_alias}(desc=nil, options={}, &block)
                  updated_options = options.update(:caller => caller[0])
                  updated_options.update(#{extra_options.inspect})
                  examples << Rspec::Core::Example.new(self, desc, updated_options, block)
                end
              END_RUBY
  module_eval(new_alias, __FILE__, __LINE__)
end

def self.ancestors(superclass_last=false)
  classes = []
  current_class = self
  while current_class < Rspec::Core::ExampleGroup
    superclass_last ? classes << current_class : classes.unshift(current_class)
    current_class = current_class.superclass
  end
  classes
end

def self.before_all_ivars
  @before_all_ivars ||= {}
end

def self.before_ancestors
  @_before_ancestors ||= ancestors 
end

def self.describe(*args, &behaviour_block)
  raise(ArgumentError, "No arguments given.  You must a least supply a type or description") if args.empty? 
  raise(ArgumentError, "You must supply a block when calling describe") if behaviour_block.nil?
  # TODO: Pull out the below into a metadata object, that we can defer the subclassing if necessary
  # describe 'foo', :shared => true will need this to be completed first
  subclass('NestedLevel') do
    args << {} unless args.last.is_a?(Hash)
    args.last.update(:behaviour_block => behaviour_block, :caller => caller(2))
    set_it_up(*args)
    module_eval(&behaviour_block)
  end
end

def self.described_class
  describes || description
end

def self.describes
  metadata[:behaviour][:describes]
end

def self.description
  metadata[:behaviour][:description]
end

def self.eval_after_alls(running_behaviour)
  after_alls.each { |blk| running_behaviour.instance_eval(&blk) }
  Rspec::Core.configuration.find_advice(:after, :all, self).each { |blk| running_behaviour.instance_eval(&blk) }
  before_all_ivars.keys.each { |ivar| before_all_ivars[ivar] = running_behaviour.instance_variable_get(ivar) }
end

def self.eval_after_eachs(running_behaviour)
  after_ancestors.each { |ancestor| ancestor.after_eachs.each { |blk| running_behaviour.instance_eval(&blk) } }
  Rspec::Core.configuration.find_advice(:after, :each, self).each { |blk| running_behaviour.instance_eval(&blk) }
end

def self.eval_before_alls(running_behaviour)
  superclass.before_all_ivars.each { |ivar, val| running_behaviour.instance_variable_set(ivar, val) }
  Rspec::Core.configuration.find_advice(:before, :all, self).each { |blk| running_behaviour.instance_eval(&blk) }
  before_alls.each { |blk| running_behaviour.instance_eval(&blk) }
  running_behaviour.instance_variables.each { |ivar| before_all_ivars[ivar] = running_behaviour.instance_variable_get(ivar) }
end

def self.eval_before_eachs(running_behaviour)
  Rspec::Core.configuration.find_advice(:before, :each, self).each { |blk| running_behaviour.instance_eval(&blk) }
  before_ancestors.each { |ancestor| ancestor.before_eachs.each { |blk| running_behaviour.instance_eval(&blk) } }
end

def self.example(desc=nil, options={}, &block)
  examples << Rspec::Core::Example.new(self, desc, options.update(:caller => caller[0]), block)
end

def self.examples
  @_examples ||= []
end

def self.examples_to_run
  @_examples_to_run ||= []
end

def self.extended_modules #:nodoc:
  ancestors = class << self; ancestors end
  ancestors.select { |mod| mod.class == Module } - [ Object, Kernel ]
end

def self.file_path
  metadata[:behaviour][:file_path]
end

def self.inherited(klass)
  super
  Rspec::Core.configuration.autorun!
  Rspec::Core.world.behaviours << klass
end

def self.it_should_behave_like(*names)
  Rspec::Core.world.shared_behaviours.each do |name, block|
    module_eval(&block) if names.include?(name)
  end
end

def self.let(name, &block)
  # Should we block defining method names already defined?
  define_method(name) do
    assignments[name] ||= instance_eval(&block)
  end
end

def self.metadata
  @metadata 
end

def self.name(friendly=true)
  friendly ? metadata[:behaviour][:name] : super
end

def self.run(reporter)
  example_world = new
  reporter.add_behaviour(self)
  eval_before_alls(example_world)
  success = run_examples(example_world, reporter)
  eval_after_alls(example_world)
  success
end

def self.run_examples(example_world, reporter)
  examples_to_run.map do |ex| 
    result = ex.run(example_world) 
    example_world.__reset__
    before_all_ivars.each { |k, v| example_world.instance_variable_set(k, v) } 
    result
  end.all?
end

def self.set_it_up(*args)
  @metadata = Rspec::Core::Metadata.process(self.superclass.metadata, *args)
  Rspec::Core.configuration.find_modules(self).each do |include_or_extend, mod, opts|
    if include_or_extend == :extend
      send(:extend, mod) unless extended_modules.include?(mod)
    else
      send(:include, mod) unless included_modules.include?(mod)
    end
  end
end

def self.subclass(base_name, &body) # :nodoc:
  @_subclass_count ||= 0
  @_subclass_count += 1
  klass = Class.new(self)
  class_name = "#{base_name}_#{@_subclass_count}"
  const_set(class_name, klass)
  klass.instance_eval(&body)
  klass
end

def self.to_s
  self == Rspec::Core::ExampleGroup ? 'Rspec::Core::ExampleGroup' : name
end

def __reset__
  instance_variables.each { |ivar| remove_instance_variable(ivar) }
  assignments.clear
end

def assignments
  @assignments ||= {}
end