sanger/sequencescape

# frozen_string_literal: true
# {include:file:docs/api_v1.md}
module Api
  # Sinatra application which provides routing for the V1 API
  # Automatically generates routes from the files listed under `app/api/endpoints`
  # This particular class handles the actual root response, other endpoints are
  # handled by {Api::EndpointHandler}
  class RootService < ::Core::Service
    # @note This is partly a hack but it suffices to keep the dynamic ability to write endpoints.
    ALL_SERVICES_AVAILABLE =
      Dir
        .glob(File.join(Rails.root, %w[app api endpoints ** *.rb])) # rubocop:todo Rails/RootPathnameMethods
        .to_h do |file|
          handler = file.gsub(%r{^.+/(endpoints/.+).rb$}, '\1').camelize.constantize
          [handler.root.tr('/', '_'), handler]
        end

    use Api::EndpointHandler

    module RootResponse
      # rubocop:todo Metrics/MethodLength
      def services(services) # rubocop:todo Metrics/AbcSize
        self.object = services
        def @owner.each(&block)
          ::Core::Io::Buffer.new(block) do |buffer|
            ::Core::Io::Json::Stream
              .new(buffer)
              .open do |stream|
                stream.attribute('revision', 2)
                object.each do |model_in_json, endpoint|
                  stream.block(model_in_json) do |nested_stream|
                    nested_stream.block('actions') do |actions_stream|
                      endpoint
                        .model_handler
                        .send(:actions, endpoint.model_handler, response: self, endpoint: endpoint)
                        .map { |action, url| actions_stream.attribute(action, url) }
                    end
                  end
                end
              end
          end
        end
      end
      # rubocop:enable Metrics/MethodLength
    end

    # It appears that if you go through a service like nginx or mongrel cluster(?) that the trailing
    # slash gets stripped off any requests, so we have to account for that with the root actions.
    get(%r{/?}) do
      result =
        report('root') do
          ::Core::Service::Request
            .new(request.fullpath) do |request|
              request.service = self
              request.path = '/'
            end
            .response do |response|
              class << response
                include RootResponse
              end
              response.services(ALL_SERVICES_AVAILABLE)
            end
        end

      body(result)
    end

    %i[post put delete].each { |action| send(action, %r{/?}) { raise MethodNotAllowed, [:get] } }
  end
end