class Kafka::Statsd::ConsumerSubscriber

def join_group(event)
  client = event.payload.fetch(:client_id)
  group_id = event.payload.fetch(:group_id)
  timing("consumer.#{client}.#{group_id}.join_group", event.duration)
  if event.payload.key?(:exception)
    increment("consumer.#{client}.#{group_id}.join_group.errors")
  end
end

def leave_group(event)
  client = event.payload.fetch(:client_id)
  group_id = event.payload.fetch(:group_id)
  timing("consumer.#{client}.#{group_id}.leave_group", event.duration)
  if event.payload.key?(:exception)
    increment("consumer.#{client}.#{group_id}.leave_group.errors")
  end
end

def pause_status(event)
  client = event.payload.fetch(:client_id)
  group_id = event.payload.fetch(:group_id)
  topic = event.payload.fetch(:topic)
  partition = event.payload.fetch(:partition)
  duration = event.payload.fetch(:duration)
  gauge("consumer.#{client}.#{group_id}.#{topic}.#{partition}.pause.duration", duration)
end

def process_batch(event)
  lag = event.payload.fetch(:offset_lag)
  messages = event.payload.fetch(:message_count)
  client = event.payload.fetch(:client_id)
  group_id = event.payload.fetch(:group_id)
  topic = event.payload.fetch(:topic)
  partition = event.payload.fetch(:partition)
  if event.payload.key?(:exception)
    increment("consumer.#{client}.#{group_id}.#{topic}.#{partition}.process_batch.errors")
  else
    timing("consumer.#{client}.#{group_id}.#{topic}.#{partition}.process_batch.latency", event.duration)
    count("consumer.#{client}.#{group_id}.#{topic}.#{partition}.messages", messages)
  end
  gauge("consumer.#{client}.#{group_id}.#{topic}.#{partition}.lag", lag)
end

def process_message(event)
  offset_lag = event.payload.fetch(:offset_lag)
  create_time = event.payload.fetch(:create_time)
  client = event.payload.fetch(:client_id)
  group_id = event.payload.fetch(:group_id)
  topic = event.payload.fetch(:topic)
  partition = event.payload.fetch(:partition)
  time_lag = create_time && ((Time.now - create_time) * 1000).to_i
  if event.payload.key?(:exception)
    increment("consumer.#{client}.#{group_id}.#{topic}.#{partition}.process_message.errors")
  else
    timing("consumer.#{client}.#{group_id}.#{topic}.#{partition}.process_message.latency", event.duration)
    increment("consumer.#{client}.#{group_id}.#{topic}.#{partition}.messages")
  end
  gauge("consumer.#{client}.#{group_id}.#{topic}.#{partition}.lag", offset_lag)
  # Not all messages have timestamps.
  if time_lag
    gauge("consumer.#{client}.#{group_id}.#{topic}.#{partition}.time_lag", time_lag)
  end
end

def sync_group(event)
  client = event.payload.fetch(:client_id)
  group_id = event.payload.fetch(:group_id)
  timing("consumer.#{client}.#{group_id}.sync_group", event.duration)
  if event.payload.key?(:exception)
    increment("consumer.#{client}.#{group_id}.sync_group.errors")
  end
end