module RSpec
  module Rails
    module Swagger
      class RouteParser
        attr_reader :controller

        def initialize(controller)
          @controller = controller
        end

        def routes
          ::Rails.application.routes.routes.select do |route|
            route.defaults[:controller] == controller
          end.reduce({}) do |tree, route|
            path = path_from(route)
            verb = verb_from(route)
            tree[path] ||= { params: params_from(route), actions: {} }
            tree[path][:actions][verb] = { summary: summary_from(route) }
            tree
          end
        end

        private

        def path_from(route)
          route.path.spec.to_s
            .chomp('(.:format)') # Ignore any format suffix
            .gsub(/:([^\/.?]+)/, '{\1}') # Convert :id to {id}
        end

        def verb_from(route)
          verb = route.verb
          if verb.kind_of? String
            verb.downcase
          else
            verb.source.gsub(/[$^]/, '').downcase
          end
        end

        def summary_from(route)
          verb = route.requirements[:action]
          noun = route.requirements[:controller].split('/').last.singularize

          # Apply a few customizations to make things more readable
          case verb
          when 'index'
            verb = 'list'
            noun = noun.pluralize
          when 'destroy'
            verb = 'delete'
          end

          "#{verb} #{noun}"
        end

        def params_from(route)
          route.segments - ['format']
        end
      end
    end
  end
end