require 'action_controller'

# allows to install a filter to the route set by calling: map.filter 'locale'
ActionController::Routing::RouteSet::Mapper.class_eval do
  def filter(*args)
    @set.add_filters(*args)
  end
end

# same here for the optimized url generation in named routes
ActionController::Routing::RouteSet::NamedRouteCollection.class_eval do
  # gosh. monkey engineering optimization code
  def generate_optimisation_block_with_filtering(*args)
    code = generate_optimisation_block_without_filtering(*args)
    if match = code.match(%r(^return (.*) if (.*)))
      # returned string must not contain newlines, or we'll spill out of inline code comments in
      # ActionController::Routing::RouteSet::NamedRouteCollection#define_url_helper
      (ActionPack::VERSION::MINOR >= 3 && ActionPack::VERSION::TINY >= 9 ? "#{match[1]}.tap { |result|" : "returning(#{match[1]}) { |result|") +
      "  ActionController::Routing::Routes.filters.run(:around_generate, *args, &lambda{ result }) " +
      "} if #{match[2]}"
    end
  end
  alias_method_chain :generate_optimisation_block, :filtering
end

ActionController::Routing::RouteSet.class_eval do
  attr_writer :filters

  def filters
    @filters ||= RoutingFilter::Chain.new
  end

  def add_filters(*names)
    options = names.extract_options!
    names.each { |name| filters.unshift(RoutingFilter.build(name, options)) }
  end

  def recognize_path_with_filtering(path, env = {})
    path = ::URI.unescape(path.dup) # string is frozen due to memoize
    filters.run(:around_recognize, path, env, &lambda{ recognize_path_without_filtering(path, env) })
  end
  alias_method_chain :recognize_path, :filtering

  def generate_with_filtering(*args)
    filters.run(:around_generate, args.first, &lambda{ generate_without_filtering(*args) })
  end
  alias_method_chain :generate, :filtering

  def clear_with_filtering!
    @filters.clear if @filters
    clear_without_filtering!
  end
  alias_method_chain :clear!, :filtering

  # add some useful information to the request environment
  # right, this is from jamis buck's excellent article about routes internals
  # http://weblog.jamisbuck.org/2006/10/26/monkey-patching-rails-extending-routes-2
  # TODO move this ... where?
  alias_method :extract_request_environment_without_host, :extract_request_environment unless method_defined? :extract_request_environment_without_host
  def extract_request_environment(request)
    extract_request_environment_without_host(request).tap do |env|
      env.merge! :host => request.host,
                 :port => request.port,
                 :host_with_port => request.host_with_port,
                 :domain => request.domain,
                 :subdomain => request.subdomains.first
    end
  end
end