module Datadog::Tracing::Contrib::ActionPack::ActionController::Instrumentation

def finish_processing(payload)
  return unless Tracing.enabled?
  # retrieve the tracing context and the latest active span
  tracing_context = payload.fetch(:tracing_context)
  trace = tracing_context[:dd_request_trace]
  span = tracing_context[:dd_request_span]
  return unless span && !span.finished?
  begin
    # We repeat this in both start and at finish because the resource may have changed during the request
    trace.resource = span.resource unless payload[:headers][:request_exception]
    # Set analytics sample rate
    Utils.set_analytics_sample_rate(span)
    # Measure service stats
    Contrib::Analytics.set_measured(span)
    span.set_tag(Ext::TAG_ROUTE_ACTION, payload.fetch(:action))
    span.set_tag(Ext::TAG_ROUTE_CONTROLLER, payload.fetch(:controller))
    exception = payload[:exception_object]
    if exception.nil?
      # [christian] in some cases :status is not defined,
      # rather than firing an error, simply acknowledge we don't know it.
      status = payload.fetch(:status, '?').to_s
      span.status = 1 if status.start_with?('5')
    elsif Utils.exception_is_error?(exception)
      span.set_error(exception)
    end
  ensure
    span.finish
  end
rescue StandardError => e
  Datadog.logger.error(e.message)
end

def start_processing(payload)
  return unless Tracing.enabled?
  # trace the execution
  service = Datadog.configuration.tracing[:action_pack][:service_name]
  type = Tracing::Metadata::Ext::HTTP::TYPE_INBOUND
  span = Tracing.trace(
    Ext::SPAN_ACTION_CONTROLLER,
    service: service,
    span_type: type,
    resource: "#{payload.fetch(:controller)}##{payload.fetch(:action)}",
  )
  trace = Tracing.active_trace
  # attach the current span to the tracing context
  tracing_context = payload.fetch(:tracing_context)
  tracing_context[:dd_request_trace] = trace
  tracing_context[:dd_request_span] = span
  # We want the route to show up as the trace's resource
  trace.resource = span.resource unless payload[:headers][:request_exception]
  span.set_tag(Tracing::Metadata::Ext::TAG_COMPONENT, Ext::TAG_COMPONENT)
  span.set_tag(Tracing::Metadata::Ext::TAG_OPERATION, Ext::TAG_OPERATION_CONTROLLER)
rescue StandardError => e
  Datadog.logger.error(e.message)
end