require 'delayed/plugin'

require_relative '../../metadata/ext'
require_relative '../analytics'
require_relative 'ext'

module Datadog
  module Tracing
    module Contrib
      module DelayedJob
        # DelayedJob plugin that instruments invoke_job hook
        class Plugin < Delayed::Plugin
          def self.instrument_invoke(job, &block)
            return yield(job) unless Tracing.enabled?

            Tracing.trace(
              Ext::SPAN_JOB,
              service: configuration[:service_name],
              resource: job_name(job),
              on_error: configuration[:error_handler]
            ) do |span|
              set_sample_rate(span)

              # Measure service stats
              Contrib::Analytics.set_measured(span)

              span.set_tag(Ext::TAG_ID, job.id)
              span.set_tag(Ext::TAG_QUEUE, job.queue) if job.queue
              span.set_tag(Ext::TAG_PRIORITY, job.priority)
              span.set_tag(Ext::TAG_ATTEMPTS, job.attempts)
              span.span_type = Tracing::Metadata::Ext::AppTypes::TYPE_WORKER

              span.set_tag(Tracing::Metadata::Ext::TAG_COMPONENT, Ext::TAG_COMPONENT)
              span.set_tag(Tracing::Metadata::Ext::TAG_OPERATION, Ext::TAG_OPERATION_JOB)

              span.set_tag(Tracing::Metadata::Ext::TAG_KIND, Tracing::Metadata::Ext::SpanKind::TAG_CONSUMER)

              span.set_tag(Contrib::Ext::Messaging::TAG_SYSTEM, Ext::TAG_COMPONENT)

              yield job
            end
          end

          def self.instrument_enqueue(job, &block)
            return yield(job) unless Tracing.enabled?

            Tracing.trace(
              Ext::SPAN_ENQUEUE,
              service: configuration[:client_service_name],
              resource: job_name(job)
            ) do |span|
              set_sample_rate(span)

              # Measure service stats
              Contrib::Analytics.set_measured(span)

              span.set_tag(Ext::TAG_QUEUE, job.queue) if job.queue
              span.set_tag(Ext::TAG_PRIORITY, job.priority)
              span.span_type = Tracing::Metadata::Ext::AppTypes::TYPE_WORKER

              span.set_tag(Tracing::Metadata::Ext::TAG_COMPONENT, Ext::TAG_COMPONENT)
              span.set_tag(Tracing::Metadata::Ext::TAG_OPERATION, Ext::TAG_OPERATION_ENQUEUE)

              span.set_tag(Tracing::Metadata::Ext::TAG_KIND, Tracing::Metadata::Ext::SpanKind::TAG_PRODUCER)

              span.set_tag(Contrib::Ext::Messaging::TAG_SYSTEM, Ext::TAG_COMPONENT)

              yield job
            end
          end

          def self.flush(worker, &block)
            yield worker

            Tracing.shutdown! if Tracing.enabled?
          end

          def self.configuration
            Datadog.configuration.tracing[:delayed_job]
          end

          def self.job_name(job)
            # When DelayedJob is used through ActiveJob, we need to parse the payload differentely
            # to get the actual job name
            return job.payload_object.job_data['job_class'] if job.payload_object.respond_to?(:job_data)

            job.name
          end

          def self.set_sample_rate(span)
            # Set analytics sample rate
            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
            end
          end

          callbacks do |lifecycle|
            lifecycle.around(:invoke_job) { |job, &block| instrument_invoke(job, &block) }
            lifecycle.around(:enqueue) { |job, &block| instrument_enqueue(job, &block) }
            lifecycle.around(:execute) { |worker, &block| flush(worker, &block) }
          end
        end
      end
    end
  end
end