module NewRelic::Agent::Instrumentation
  class Grape < Grape::Middleware::Base
    include ControllerInstrumentation

    def call!(env)
      @env = env

      @newrelic_request = ::Rack::Request.new(env)
      trace_options = {
        :category => :rack,
        :path => "#{request_method} #{request_path}",
        :request => @newrelic_request
      }
      perform_action_with_newrelic_trace(trace_options) do
        @app_response = @app.call(@env)
      end
    end

    def request_path
      env['api.endpoint'].routes.first.route_path[1..-1].gsub("/", "-").sub(/\(\.:format\)\z/, "")
    end

    def request_method
      @newrelic_request.request_method
    end
  end
end

DependencyDetection.defer do
  @name = :grape

  depends_on do
    defined?(::Grape) and not ::NewRelic::Control.instance['disable_grape']
  end

  executes do
    NewRelic::Agent.logger.debug 'Installing Grape instrumentation'
  end

  executes do
    ::Grape::Endpoint.class_eval do
      alias_method :origin_build_middleware, :build_middleware

      def build_middleware
        builder = origin_build_middleware
        builder.use ::NewRelic::Agent::Instrumentation::Grape
        builder
      end
    end
  end
end