require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/object/with_options'

module ActionDispatch
  module Routing
    class RouteSet
      attr_accessor :controller_namespaces

      CONTROLLER_REGEXP = /[_a-zA-Z0-9]+/

      def controller_constraints
        @controller_constraints ||= begin
          namespaces = controller_namespaces + in_memory_controller_namespaces
          source = namespaces.map { |ns| "#{Regexp.escape(ns)}/#{CONTROLLER_REGEXP.source}" }
          source << CONTROLLER_REGEXP.source
          Regexp.compile(source.sort.reverse.join('|'))
        end
      end

      def in_memory_controller_namespaces
        namespaces = Set.new
        ActionController::Base.subclasses.each do |klass|
          controller_name = klass.underscore
          namespaces << controller_name.split('/')[0...-1].join('/')
        end
        namespaces.delete('')
        namespaces
      end
    end

    # Mapper instances are used to build routes. The object passed to the draw
    # block in config/routes.rb is a Mapper instance.
    #
    # Mapper instances have relatively few instance methods, in order to avoid
    # clashes with named routes.
    #
    # == Overview
    #
    # ActionController::Resources are a way of defining RESTful \resources.  A RESTful \resource, in basic terms,
    # is something that can be pointed at and it will respond with a representation of the data requested.
    # In real terms this could mean a user with a browser requests an HTML page, or that a desktop application
    # requests XML data.
    #
    # RESTful design is based on the assumption that there are four generic verbs that a user of an
    # application can request from a \resource (the noun).
    #
    # \Resources can be requested using four basic HTTP verbs (GET, POST, PUT, DELETE), the method used
    # denotes the type of action that should take place.
    #
    # === The Different Methods and their Usage
    #
    # * GET    - Requests for a \resource, no saving or editing of a \resource should occur in a GET request.
    # * POST   - Creation of \resources.
    # * PUT    - Editing of attributes on a \resource.
    # * DELETE - Deletion of a \resource.
    #
    # === Examples
    #
    #   # A GET request on the Posts resource is asking for all Posts
    #   GET /posts
    #
    #   # A GET request on a single Post resource is asking for that particular Post
    #   GET /posts/1
    #
    #   # A POST request on the Posts resource is asking for a Post to be created with the supplied details
    #   POST /posts # with => { :post => { :title => "My Whizzy New Post", :body => "I've got a brand new combine harvester" } }
    #
    #   # A PUT request on a single Post resource is asking for a Post to be updated
    #   PUT /posts # with => { :id => 1, :post => { :title => "Changed Whizzy Title" } }
    #
    #   # A DELETE request on a single Post resource is asking for it to be deleted
    #   DELETE /posts # with => { :id => 1 }
    #
    # By using the REST convention, users of our application can assume certain things about how the data
    # is requested and how it is returned.  Rails simplifies the routing part of RESTful design by
    # supplying you with methods to create them in your routes.rb file.
    #
    # Read more about REST at http://en.wikipedia.org/wiki/Representational_State_Transfer
    class DeprecatedMapper #:nodoc:
      def initialize(set) #:nodoc:
        @set = set
      end

      # Create an unnamed route with the provided +path+ and +options+. See
      # ActionDispatch::Routing for an introduction to routes.
      def connect(path, options = {})
        options = options.dup

        if conditions = options.delete(:conditions)
          conditions = conditions.dup
          method = [conditions.delete(:method)].flatten.compact
          method.map! { |m|
            m = m.to_s.upcase

            if m == "HEAD"
              raise ArgumentError, "HTTP method HEAD is invalid in route conditions. Rails processes HEAD requests the same as GETs, returning just the response headers"
            end

            unless HTTP_METHODS.include?(m.downcase.to_sym)
              raise ArgumentError, "Invalid HTTP method specified in route conditions"
            end

            m
          }

          if method.length > 1
            method = Regexp.union(*method)
          elsif method.length == 1
            method = method.first
          else
            method = nil
          end
        end

        path_prefix = options.delete(:path_prefix)
        name_prefix = options.delete(:name_prefix)
        namespace  = options.delete(:namespace)

        name = options.delete(:_name)
        name = "#{name_prefix}#{name}" if name_prefix

        requirements = options.delete(:requirements) || {}
        defaults = options.delete(:defaults) || {}
        options.each do |k, v|
          if v.is_a?(Regexp)
            if value = options.delete(k)
              requirements[k.to_sym] = value
            end
          else
            value = options.delete(k)
            defaults[k.to_sym] = value.is_a?(Symbol) ? value : value.to_param
          end
        end

        requirements.each do |_, requirement|
          if requirement.source =~ %r{\A(\\A|\^)|(\\Z|\\z|\$)\Z}
            raise ArgumentError, "Regexp anchor characters are not allowed in routing requirements: #{requirement.inspect}"
          end
          if requirement.multiline?
            raise ArgumentError, "Regexp multiline option not allowed in routing requirements: #{requirement.inspect}"
          end
        end

        requirements[:controller] ||= @set.controller_constraints

        if defaults[:controller]
          defaults[:action] ||= 'index'
          defaults[:controller] = defaults[:controller].to_s
          defaults[:controller] = "#{namespace}#{defaults[:controller]}" if namespace
        end

        if defaults[:action]
          defaults[:action] = defaults[:action].to_s
        end

        if path.is_a?(String)
          path = "#{path_prefix}/#{path}" if path_prefix
          path = path.gsub('.:format', '(.:format)')
          path = optionalize_trailing_dynamic_segments(path, requirements, defaults)
          glob = $1.to_sym if path =~ /\/\*(\w+)$/
          path = ::Rack::Mount::Utils.normalize_path(path)

          if glob && !defaults[glob].blank?
            raise ActionController::RoutingError, "paths cannot have non-empty default values"
          end
        end

        app = Routing::RouteSet::Dispatcher.new(:defaults => defaults, :glob => glob)

        conditions = {}
        conditions[:request_method] = method if method
        conditions[:path_info] = path if path

        @set.add_route(app, conditions, requirements, defaults, name)
      end

      def optionalize_trailing_dynamic_segments(path, requirements, defaults) #:nodoc:
        path = (path =~ /^\//) ? path.dup : "/#{path}"
        optional, segments = true, []

        required_segments = requirements.keys
        required_segments -= defaults.keys.compact

        old_segments = path.split('/')
        old_segments.shift
        length = old_segments.length

        old_segments.reverse.each_with_index do |segment, index|
          required_segments.each do |required|
            if segment =~ /#{required}/
              optional = false
              break
            end
          end

          if optional
            if segment == ":id" && segments.include?(":action")
              optional = false
            elsif segment == ":controller" || segment == ":action" || segment == ":id"
              # Ignore
            elsif !(segment =~ /^:\w+$/) &&
                !(segment =~ /^:\w+\(\.:format\)$/)
              optional = false
            elsif segment =~ /^:(\w+)$/
              if defaults.has_key?($1.to_sym)
                defaults.delete($1.to_sym) if defaults[$1.to_sym].nil?
              else
                optional = false
              end
            end
          end

          if optional && index < length - 1
            segments.unshift('(/', segment)
            segments.push(')')
          elsif optional
            segments.unshift('/(', segment)
            segments.push(')')
          else
            segments.unshift('/', segment)
          end
        end

        segments.join
      end
      private :optionalize_trailing_dynamic_segments

      # Creates a named route called "root" for matching the root level request.
      def root(options = {})
        if options.is_a?(Symbol)
          if source_route = @set.named_routes.routes[options]
            options = source_route.defaults.merge({ :conditions => source_route.conditions })
          end
        end
        named_route("root", '', options)
      end

      def named_route(name, path, options = {}) #:nodoc:
        options[:_name] = name
        connect(path, options)
      end

      # Enables the use of resources in a module by setting the name_prefix, path_prefix, and namespace for the model.
      # Example:
      #
      #   map.namespace(:admin) do |admin|
      #     admin.resources :products,
      #       :has_many => [ :tags, :images, :variants ]
      #   end
      #
      # This will create +admin_products_url+ pointing to "admin/products", which will look for an Admin::ProductsController.
      # It'll also create +admin_product_tags_url+ pointing to "admin/products/#{product_id}/tags", which will look for
      # Admin::TagsController.
      def namespace(name, options = {}, &block)
        if options[:namespace]
          with_options({:path_prefix => "#{options.delete(:path_prefix)}/#{name}", :name_prefix => "#{options.delete(:name_prefix)}#{name}_", :namespace => "#{options.delete(:namespace)}#{name}/" }.merge(options), &block)
        else
          with_options({:path_prefix => name, :name_prefix => "#{name}_", :namespace => "#{name}/" }.merge(options), &block)
        end
      end

      def method_missing(route_name, *args, &proc) #:nodoc:
        super unless args.length >= 1 && proc.nil?
        named_route(route_name, *args)
      end

      INHERITABLE_OPTIONS = :namespace, :shallow

      class Resource #:nodoc:
        DEFAULT_ACTIONS = :index, :create, :new, :edit, :show, :update, :destroy

        attr_reader :collection_methods, :member_methods, :new_methods
        attr_reader :path_prefix, :name_prefix, :path_segment
        attr_reader :plural, :singular
        attr_reader :options, :defaults

        def initialize(entities, options, defaults)
          @plural   ||= entities
          @singular ||= options[:singular] || plural.to_s.singularize
          @path_segment = options.delete(:as) || @plural

          @options = options
          @defaults = defaults

          arrange_actions
          add_default_actions
          set_allowed_actions
          set_prefixes
        end

        def controller
          @controller ||= "#{options[:namespace]}#{(options[:controller] || plural).to_s}"
        end

        def requirements(with_id = false)
          @requirements   ||= @options[:requirements] || {}
          @id_requirement ||= { :id => @requirements.delete(:id) || /[^#{Routing::SEPARATORS.join}]+/ }

          with_id ? @requirements.merge(@id_requirement) : @requirements
        end

        def conditions
          @conditions ||= @options[:conditions] || {}
        end

        def path
          @path ||= "#{path_prefix}/#{path_segment}"
        end

        def new_path
          new_action   = self.options[:path_names][:new] if self.options[:path_names]
          new_action ||= self.defaults[:path_names][:new]
          @new_path  ||= "#{path}/#{new_action}"
        end

        def shallow_path_prefix
          @shallow_path_prefix ||= @options[:shallow] ? @options[:namespace].try(:sub, /\/$/, '') : path_prefix
        end

        def member_path
          @member_path ||= "#{shallow_path_prefix}/#{path_segment}/:id"
        end

        def nesting_path_prefix
          @nesting_path_prefix ||= "#{shallow_path_prefix}/#{path_segment}/:#{singular}_id"
        end

        def shallow_name_prefix
          @shallow_name_prefix ||= @options[:shallow] ? @options[:namespace].try(:gsub, /\//, '_') : name_prefix
        end

        def nesting_name_prefix
          "#{shallow_name_prefix}#{singular}_"
        end

        def action_separator
          @action_separator ||= ActionController::Base.resource_action_separator
        end

        def uncountable?
          @singular.to_s == @plural.to_s
        end

        def has_action?(action)
          !DEFAULT_ACTIONS.include?(action) || action_allowed?(action)
        end

        protected
          def arrange_actions
            @collection_methods = arrange_actions_by_methods(options.delete(:collection))
            @member_methods     = arrange_actions_by_methods(options.delete(:member))
            @new_methods        = arrange_actions_by_methods(options.delete(:new))
          end

          def add_default_actions
            add_default_action(member_methods, :get, :edit)
            add_default_action(new_methods, :get, :new)
          end

          def set_allowed_actions
            only, except = @options.values_at(:only, :except)
            @allowed_actions ||= {}

            if only == :all || except == :none
              only = nil
              except = []
            elsif only == :none || except == :all
              only = []
              except = nil
            end

            if only
              @allowed_actions[:only] = Array(only).map {|a| a.to_sym }
            elsif except
              @allowed_actions[:except] = Array(except).map {|a| a.to_sym }
            end
          end

          def action_allowed?(action)
            only, except = @allowed_actions.values_at(:only, :except)
            (!only || only.include?(action)) && (!except || !except.include?(action))
          end

          def set_prefixes
            @path_prefix = options.delete(:path_prefix)
            @name_prefix = options.delete(:name_prefix)
          end

          def arrange_actions_by_methods(actions)
            (actions || {}).inject({}) do |flipped_hash, (key, value)|
              (flipped_hash[value] ||= []) << key
              flipped_hash
            end
          end

          def add_default_action(collection, method, action)
            (collection[method] ||= []).unshift(action)
          end
      end

      class SingletonResource < Resource #:nodoc:
        def initialize(entity, options, defaults)
          @singular = @plural = entity
          options[:controller] ||= @singular.to_s.pluralize
          super
        end

        alias_method :shallow_path_prefix, :path_prefix
        alias_method :shallow_name_prefix, :name_prefix
        alias_method :member_path,         :path
        alias_method :nesting_path_prefix, :path
      end

      # Creates named routes for implementing verb-oriented controllers
      # for a collection \resource.
      #
      # For example:
      #
      #   map.resources :messages
      #
      # will map the following actions in the corresponding controller:
      #
      #   class MessagesController < ActionController::Base
      #     # GET messages_url
      #     def index
      #       # return all messages
      #     end
      #
      #     # GET new_message_url
      #     def new
      #       # return an HTML form for describing a new message
      #     end
      #
      #     # POST messages_url
      #     def create
      #       # create a new message
      #     end
      #
      #     # GET message_url(:id => 1)
      #     def show
      #       # find and return a specific message
      #     end
      #
      #     # GET edit_message_url(:id => 1)
      #     def edit
      #       # return an HTML form for editing a specific message
      #     end
      #
      #     # PUT message_url(:id => 1)
      #     def update
      #       # find and update a specific message
      #     end
      #
      #     # DELETE message_url(:id => 1)
      #     def destroy
      #       # delete a specific message
      #     end
      #   end
      #
      # Along with the routes themselves, +resources+ generates named routes for use in
      # controllers and views. <tt>map.resources :messages</tt> produces the following named routes and helpers:
      #
      #   Named Route   Helpers
      #   ============  =====================================================
      #   messages      messages_url, hash_for_messages_url,
      #                 messages_path, hash_for_messages_path
      #
      #   message       message_url(id), hash_for_message_url(id),
      #                 message_path(id), hash_for_message_path(id)
      #
      #   new_message   new_message_url, hash_for_new_message_url,
      #                 new_message_path, hash_for_new_message_path
      #
      #   edit_message  edit_message_url(id), hash_for_edit_message_url(id),
      #                 edit_message_path(id), hash_for_edit_message_path(id)
      #
      # You can use these helpers instead of +url_for+ or methods that take +url_for+ parameters. For example:
      #
      #   redirect_to :controller => 'messages', :action => 'index'
      #   # and
      #   <%= link_to "edit this message", :controller => 'messages', :action => 'edit', :id => @message.id %>
      #
      # now become:
      #
      #   redirect_to messages_url
      #   # and
      #   <%= link_to "edit this message", edit_message_url(@message) # calls @message.id automatically
      #
      # Since web browsers don't support the PUT and DELETE verbs, you will need to add a parameter '_method' to your
      # form tags. The form helpers make this a little easier. For an update form with a <tt>@message</tt> object:
      #
      #   <%= form_tag message_path(@message), :method => :put %>
      #
      # or
      #
      #   <% form_for :message, @message, :url => message_path(@message), :html => {:method => :put} do |f| %>
      #
      # or
      #
      #   <% form_for @message do |f| %>
      #
      # which takes into account whether <tt>@message</tt> is a new record or not and generates the
      # path and method accordingly.
      #
      # The +resources+ method accepts the following options to customize the resulting routes:
      # * <tt>:collection</tt> - Add named routes for other actions that operate on the collection.
      #   Takes a hash of <tt>#{action} => #{method}</tt>, where method is <tt>:get</tt>/<tt>:post</tt>/<tt>:put</tt>/<tt>:delete</tt>,
      #   an array of any of the previous, or <tt>:any</tt> if the method does not matter.
      #   These routes map to a URL like /messages/rss, with a route of +rss_messages_url+.
      # * <tt>:member</tt> - Same as <tt>:collection</tt>, but for actions that operate on a specific member.
      # * <tt>:new</tt> - Same as <tt>:collection</tt>, but for actions that operate on the new \resource action.
      # * <tt>:controller</tt> - Specify the controller name for the routes.
      # * <tt>:singular</tt> - Specify the singular name used in the member routes.
      # * <tt>:requirements</tt> - Set custom routing parameter requirements; this is a hash of either
      #     regular expressions (which must match for the route to match) or extra parameters. For example:
      #
      #       map.resource :profile, :path_prefix => ':name', :requirements => { :name => /[a-zA-Z]+/, :extra => 'value' }
      #
      #     will only match if the first part is alphabetic, and will pass the parameter :extra to the controller.
      # * <tt>:conditions</tt> - Specify custom routing recognition conditions.  \Resources sets the <tt>:method</tt> value for the method-specific routes.
      # * <tt>:as</tt> - Specify a different \resource name to use in the URL path. For example:
      #     # products_path == '/productos'
      #     map.resources :products, :as => 'productos' do |product|
      #       # product_reviews_path(product) == '/productos/1234/comentarios'
      #       product.resources :product_reviews, :as => 'comentarios'
      #     end
      #
      # * <tt>:has_one</tt> - Specify nested \resources, this is a shorthand for mapping singleton \resources beneath the current.
      # * <tt>:has_many</tt> - Same has <tt>:has_one</tt>, but for plural \resources.
      #
      #   You may directly specify the routing association with +has_one+ and +has_many+ like:
      #
      #     map.resources :notes, :has_one => :author, :has_many => [:comments, :attachments]
      #
      #   This is the same as:
      #
      #     map.resources :notes do |notes|
      #       notes.resource  :author
      #       notes.resources :comments
      #       notes.resources :attachments
      #     end
      #
      # * <tt>:path_names</tt> - Specify different path names for the actions. For example:
      #     # new_products_path == '/productos/nuevo'
      #     # bids_product_path(1) == '/productos/1/licitacoes'
      #     map.resources :products, :as => 'productos', :member => { :bids => :get }, :path_names => { :new => 'nuevo', :bids => 'licitacoes' }
      #
      #   You can also set default action names from an environment, like this:
      #     config.action_controller.resources_path_names = { :new => 'nuevo', :edit => 'editar' }
      #
      # * <tt>:path_prefix</tt> - Set a prefix to the routes with required route variables.
      #
      #   Weblog comments usually belong to a post, so you might use +resources+ like:
      #
      #     map.resources :articles
      #     map.resources :comments, :path_prefix => '/articles/:article_id'
      #
      #   You can nest +resources+ calls to set this automatically:
      #
      #     map.resources :articles do |article|
      #       article.resources :comments
      #     end
      #
      #   The comment \resources work the same, but must now include a value for <tt>:article_id</tt>.
      #
      #     article_comments_url(@article)
      #     article_comment_url(@article, @comment)
      #
      #     article_comments_url(:article_id => @article)
      #     article_comment_url(:article_id => @article, :id => @comment)
      #
      #   If you don't want to load all objects from the database you might want to use the <tt>article_id</tt> directly:
      #
      #     articles_comments_url(@comment.article_id, @comment)
      #
      # * <tt>:name_prefix</tt> - Define a prefix for all generated routes, usually ending in an underscore.
      #   Use this if you have named routes that may clash.
      #
      #     map.resources :tags, :path_prefix => '/books/:book_id', :name_prefix => 'book_'
      #     map.resources :tags, :path_prefix => '/toys/:toy_id',   :name_prefix => 'toy_'
      #
      # You may also use <tt>:name_prefix</tt> to override the generic named routes in a nested \resource:
      #
      #   map.resources :articles do |article|
      #     article.resources :comments, :name_prefix => nil
      #   end
      #
      # This will yield named \resources like so:
      #
      #   comments_url(@article)
      #   comment_url(@article, @comment)
      #
      # * <tt>:shallow</tt> - If true, paths for nested resources which reference a specific member
      #   (ie. those with an :id parameter) will not use the parent path prefix or name prefix.
      #
      # The <tt>:shallow</tt> option is inherited by any nested resource(s).
      #
      # For example, 'users', 'posts' and 'comments' all use shallow paths with the following nested resources:
      #
      #   map.resources :users, :shallow => true do |user|
      #     user.resources :posts do |post|
      #       post.resources :comments
      #     end
      #   end
      #   # --> GET /users/1/posts (maps to the PostsController#index action as usual)
      #   #     also adds the usual named route called "user_posts"
      #   # --> GET /posts/2 (maps to the PostsController#show action as if it were not nested)
      #   #     also adds the named route called "post"
      #   # --> GET /posts/2/comments (maps to the CommentsController#index action)
      #   #     also adds the named route called "post_comments"
      #   # --> GET /comments/2 (maps to the CommentsController#show action as if it were not nested)
      #   #     also adds the named route called "comment"
      #
      # You may also use <tt>:shallow</tt> in combination with the +has_one+ and +has_many+ shorthand notations like:
      #
      #   map.resources :users, :has_many => { :posts => :comments }, :shallow => true
      #
      # * <tt>:only</tt> and <tt>:except</tt> - Specify which of the seven default actions should be routed to.
      #
      # <tt>:only</tt> and <tt>:except</tt> may be set to <tt>:all</tt>, <tt>:none</tt>, an action name or a
      # list of action names. By default, routes are generated for all seven actions.
      #
      # For example:
      #
      #   map.resources :posts, :only => [:index, :show] do |post|
      #     post.resources :comments, :except => [:update, :destroy]
      #   end
      #   # --> GET /posts (maps to the PostsController#index action)
      #   # --> POST /posts (fails)
      #   # --> GET /posts/1 (maps to the PostsController#show action)
      #   # --> DELETE /posts/1 (fails)
      #   # --> POST /posts/1/comments (maps to the CommentsController#create action)
      #   # --> PUT /posts/1/comments/1 (fails)
      #
      # If <tt>map.resources</tt> is called with multiple resources, they all get the same options applied.
      #
      # Examples:
      #
      #   map.resources :messages, :path_prefix => "/thread/:thread_id"
      #   # --> GET /thread/7/messages/1
      #
      #   map.resources :messages, :collection => { :rss => :get }
      #   # --> GET /messages/rss (maps to the #rss action)
      #   #     also adds a named route called "rss_messages"
      #
      #   map.resources :messages, :member => { :mark => :post }
      #   # --> POST /messages/1/mark (maps to the #mark action)
      #   #     also adds a named route called "mark_message"
      #
      #   map.resources :messages, :new => { :preview => :post }
      #   # --> POST /messages/new/preview (maps to the #preview action)
      #   #     also adds a named route called "preview_new_message"
      #
      #   map.resources :messages, :new => { :new => :any, :preview => :post }
      #   # --> POST /messages/new/preview (maps to the #preview action)
      #   #     also adds a named route called "preview_new_message"
      #   # --> /messages/new can be invoked via any request method
      #
      #   map.resources :messages, :controller => "categories",
      #         :path_prefix => "/category/:category_id",
      #         :name_prefix => "category_"
      #   # --> GET /categories/7/messages/1
      #   #     has named route "category_message"
      #
      # The +resources+ method sets HTTP method restrictions on the routes it generates. For example, making an
      # HTTP POST on <tt>new_message_url</tt> will raise a RoutingError exception. The default route in
      # <tt>config/routes.rb</tt> overrides this and allows invalid HTTP methods for \resource routes.
      def resources(*entities, &block)
        options = entities.extract_options!
        entities.each { |entity| map_resource(entity, options.dup, &block) }
      end

      # Creates named routes for implementing verb-oriented controllers for a singleton \resource.
      # A singleton \resource is global to its current context.  For unnested singleton \resources,
      # the \resource is global to the current user visiting the application, such as a user's
      # <tt>/account</tt> profile.  For nested singleton \resources, the \resource is global to its parent
      # \resource, such as a <tt>projects</tt> \resource that <tt>has_one :project_manager</tt>.
      # The <tt>project_manager</tt> should be mapped as a singleton \resource under <tt>projects</tt>:
      #
      #   map.resources :projects do |project|
      #     project.resource :project_manager
      #   end
      #
      # See +resources+ for general conventions.  These are the main differences:
      # * A singular name is given to <tt>map.resource</tt>.  The default controller name is still taken from the plural name.
      # * To specify a custom plural name, use the <tt>:plural</tt> option.  There is no <tt>:singular</tt> option.
      # * No default index route is created for the singleton \resource controller.
      # * When nesting singleton \resources, only the singular name is used as the path prefix (example: 'account/messages/1')
      #
      # For example:
      #
      #   map.resource :account
      #
      # maps these actions in the Accounts controller:
      #
      #   class AccountsController < ActionController::Base
      #     # GET new_account_url
      #     def new
      #       # return an HTML form for describing the new account
      #     end
      #
      #     # POST account_url
      #     def create
      #       # create an account
      #     end
      #
      #     # GET account_url
      #     def show
      #       # find and return the account
      #     end
      #
      #     # GET edit_account_url
      #     def edit
      #       # return an HTML form for editing the account
      #     end
      #
      #     # PUT account_url
      #     def update
      #       # find and update the account
      #     end
      #
      #     # DELETE account_url
      #     def destroy
      #       # delete the account
      #     end
      #   end
      #
      # Along with the routes themselves, +resource+ generates named routes for
      # use in controllers and views. <tt>map.resource :account</tt> produces
      # these named routes and helpers:
      #
      #   Named Route   Helpers
      #   ============  =============================================
      #   account       account_url, hash_for_account_url,
      #                 account_path, hash_for_account_path
      #
      #   new_account   new_account_url, hash_for_new_account_url,
      #                 new_account_path, hash_for_new_account_path
      #
      #   edit_account  edit_account_url, hash_for_edit_account_url,
      #                 edit_account_path, hash_for_edit_account_path
      def resource(*entities, &block)
        options = entities.extract_options!
        entities.each { |entity| map_singleton_resource(entity, options.dup, &block) }
      end

      private
        def map_resource(entities, options = {}, &block)
          resource = Resource.new(entities, options, :path_names => @set.resources_path_names)

          with_options :controller => resource.controller do |map|
            map_associations(resource, options)

            if block_given?
              with_options(options.slice(*INHERITABLE_OPTIONS).merge(:path_prefix => resource.nesting_path_prefix, :name_prefix => resource.nesting_name_prefix), &block)
            end

            map_collection_actions(map, resource)
            map_default_collection_actions(map, resource)
            map_new_actions(map, resource)
            map_member_actions(map, resource)
          end
        end

        def map_singleton_resource(entities, options = {}, &block)
          resource = SingletonResource.new(entities, options, :path_names => @set.resources_path_names)

          with_options :controller => resource.controller do |map|
            map_associations(resource, options)

            if block_given?
              with_options(options.slice(*INHERITABLE_OPTIONS).merge(:path_prefix => resource.nesting_path_prefix, :name_prefix => resource.nesting_name_prefix), &block)
            end

            map_collection_actions(map, resource)
            map_new_actions(map, resource)
            map_member_actions(map, resource)
            map_default_singleton_actions(map, resource)
          end
        end

        def map_associations(resource, options)
          map_has_many_associations(resource, options.delete(:has_many), options) if options[:has_many]

          path_prefix = "#{options.delete(:path_prefix)}#{resource.nesting_path_prefix}"
          name_prefix = "#{options.delete(:name_prefix)}#{resource.nesting_name_prefix}"

          Array(options[:has_one]).each do |association|
            resource(association, options.slice(*INHERITABLE_OPTIONS).merge(:path_prefix => path_prefix, :name_prefix => name_prefix))
          end
        end

        def map_has_many_associations(resource, associations, options)
          case associations
          when Hash
            associations.each do |association,has_many|
              map_has_many_associations(resource, association, options.merge(:has_many => has_many))
            end
          when Array
            associations.each do |association|
              map_has_many_associations(resource, association, options)
            end
          when Symbol, String
            resources(associations, options.slice(*INHERITABLE_OPTIONS).merge(:path_prefix => resource.nesting_path_prefix, :name_prefix => resource.nesting_name_prefix, :has_many => options[:has_many]))
          else
          end
        end

        def map_collection_actions(map, resource)
          resource.collection_methods.each do |method, actions|
            actions.each do |action|
              [method].flatten.each do |m|
                action_path = resource.options[:path_names][action] if resource.options[:path_names].is_a?(Hash)
                action_path ||= action

                map_resource_routes(map, resource, action, "#{resource.path}#{resource.action_separator}#{action_path}", "#{action}_#{resource.name_prefix}#{resource.plural}", m)
              end
            end
          end
        end

        def map_default_collection_actions(map, resource)
          index_route_name = "#{resource.name_prefix}#{resource.plural}"

          if resource.uncountable?
            index_route_name << "_index"
          end

          map_resource_routes(map, resource, :index, resource.path, index_route_name)
          map_resource_routes(map, resource, :create, resource.path, index_route_name)
        end

        def map_default_singleton_actions(map, resource)
          map_resource_routes(map, resource, :create, resource.path, "#{resource.shallow_name_prefix}#{resource.singular}")
        end

        def map_new_actions(map, resource)
          resource.new_methods.each do |method, actions|
            actions.each do |action|
              route_path = resource.new_path
              route_name = "new_#{resource.name_prefix}#{resource.singular}"

              unless action == :new
                route_path = "#{route_path}#{resource.action_separator}#{action}"
                route_name = "#{action}_#{route_name}"
              end

              map_resource_routes(map, resource, action, route_path, route_name, method)
            end
          end
        end

        def map_member_actions(map, resource)
          resource.member_methods.each do |method, actions|
            actions.each do |action|
              [method].flatten.each do |m|
                action_path = resource.options[:path_names][action] if resource.options[:path_names].is_a?(Hash)
                action_path ||= @set.resources_path_names[action] || action

                map_resource_routes(map, resource, action, "#{resource.member_path}#{resource.action_separator}#{action_path}", "#{action}_#{resource.shallow_name_prefix}#{resource.singular}", m, { :force_id => true })
              end
            end
          end

          route_path = "#{resource.shallow_name_prefix}#{resource.singular}"
          map_resource_routes(map, resource, :show, resource.member_path, route_path)
          map_resource_routes(map, resource, :update, resource.member_path, route_path)
          map_resource_routes(map, resource, :destroy, resource.member_path, route_path)
        end

        def map_resource_routes(map, resource, action, route_path, route_name = nil, method = nil, resource_options = {} )
          if resource.has_action?(action)
            action_options = action_options_for(action, resource, method, resource_options)
            formatted_route_path = "#{route_path}.:format"

            if route_name && @set.named_routes[route_name.to_sym].nil?
              map.named_route(route_name, formatted_route_path, action_options)
            else
              map.connect(formatted_route_path, action_options)
            end
          end
        end

        def add_conditions_for(conditions, method)
          returning({:conditions => conditions.dup}) do |options|
            options[:conditions][:method] = method unless method == :any
          end
        end

        def action_options_for(action, resource, method = nil, resource_options = {})
          default_options = { :action => action.to_s }
          require_id = !resource.kind_of?(SingletonResource)
          force_id = resource_options[:force_id] && !resource.kind_of?(SingletonResource)

          case default_options[:action]
            when "index", "new"; default_options.merge(add_conditions_for(resource.conditions, method || :get)).merge(resource.requirements)
            when "create";       default_options.merge(add_conditions_for(resource.conditions, method || :post)).merge(resource.requirements)
            when "show", "edit"; default_options.merge(add_conditions_for(resource.conditions, method || :get)).merge(resource.requirements(require_id))
            when "update";       default_options.merge(add_conditions_for(resource.conditions, method || :put)).merge(resource.requirements(require_id))
            when "destroy";      default_options.merge(add_conditions_for(resource.conditions, method || :delete)).merge(resource.requirements(require_id))
            else                 default_options.merge(add_conditions_for(resource.conditions, method)).merge(resource.requirements(force_id))
          end
        end
    end
  end
end