require 'delegate'

module ActionDispatch
  module Routing
    class RouteWrapper < SimpleDelegator
      def endpoint
        rack_app ? rack_app.inspect : "#{controller}##{action}"
      end

      def constraints
        requirements.except(:controller, :action)
      end

      def rack_app(app = self.app)
        @rack_app ||= begin
          class_name = app.class.name.to_s
          if class_name == "ActionDispatch::Routing::Mapper::Constraints"
            rack_app(app.app)
          elsif ActionDispatch::Routing::Redirect === app || class_name !~ /^ActionDispatch::Routing/
            app
          end
        end
      end

      def verb
        super.source.gsub(/[$^]/, '')
      end

      def path
        super.spec.to_s
      end

      def name
        super.to_s
      end

      def reqs
        @reqs ||= begin
          reqs = endpoint
          reqs += " #{constraints.to_s}" unless constraints.empty?
          reqs
        end
      end

      def controller
        requirements[:controller] || ':controller'
      end

      def action
        requirements[:action] || ':action'
      end

      def internal?
        controller =~ %r{\Arails/(info|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}}
      end

      def engine?
        rack_app && rack_app.respond_to?(:routes)
      end
    end

    ##
    # This class is just used for displaying route information when someone
    # executes `rake routes` or looks at the RoutingError page.
    # People should not use this class.
    class RoutesInspector # :nodoc:
      def initialize(routes)
        @engines = {}
        @routes = routes
      end

      def format(formatter, filter = nil)
        routes_to_display = filter_routes(filter)

        routes = collect_routes(routes_to_display)
        formatter.section :application, 'Application routes', routes

        @engines.each do |name, engine_routes|
          formatter.section :engine, "Routes for #{name}", engine_routes
        end

        formatter.result
      end

      private

      def filter_routes(filter)
        if filter
          @routes.select { |route| route.defaults[:controller] == filter }
        else
          @routes
        end
      end

      def collect_routes(routes)
        routes.collect do |route|
          RouteWrapper.new(route)
        end.reject do |route|
          route.internal?
        end.collect do |route|
          collect_engine_routes(route)

          { name: route.name, verb: route.verb, path: route.path, reqs: route.reqs }
        end
      end

      def collect_engine_routes(route)
        name = route.endpoint
        return unless route.engine?
        return if @engines[name]

        routes = route.rack_app.routes
        if routes.is_a?(ActionDispatch::Routing::RouteSet)
          @engines[name] = collect_routes(routes.routes)
        end
      end
    end

    class ConsoleFormatter
      def initialize
        @buffer = []
      end

      def result
        @buffer.join("\n")
      end

      def section(type, title, routes)
        @buffer << "\n#{title}:" unless type == :application
        @buffer << draw_section(routes)
      end

      private
        def draw_section(routes)
          name_width = routes.map { |r| r[:name].length }.max
          verb_width = routes.map { |r| r[:verb].length }.max
          path_width = routes.map { |r| r[:path].length }.max

          routes.map do |r|
            "#{r[:name].rjust(name_width)} #{r[:verb].ljust(verb_width)} #{r[:path].ljust(path_width)} #{r[:reqs]}"
          end
        end
    end
  end
end