module Datadog::Tracing::Contrib::Propagation::SqlComment

def self.annotate!(span_op, mode)
  return unless mode.enabled?
  span_op.set_tag(Ext::TAG_DBM_TRACE_INJECTED, true) if mode.full?
end

def self.datadog_configuration
  Datadog.configuration
end

def self.prepend_comment(sql, span_op, trace_op, mode)
  return sql unless mode.enabled?
  tags = {
    Ext::KEY_DATABASE_SERVICE => span_op.get_tag(Tracing::Metadata::Ext::TAG_PEER_SERVICE) || span_op.service,
    Ext::KEY_ENVIRONMENT => datadog_configuration.env,
    Ext::KEY_PARENT_SERVICE => datadog_configuration.service,
    Ext::KEY_VERSION => datadog_configuration.version
  }
  if mode.full?
    # When tracing is disabled, trace_operation is a dummy object that does not contain data to build traceparent
    if datadog_configuration.tracing.enabled
      tags[Ext::KEY_TRACEPARENT] =
        Tracing::Distributed::TraceContext.new(fetcher: nil).send(:build_traceparent, trace_op.to_digest)
    else
      Datadog.logger.warn(
        'Sql comment propagation with `full` mode is aborted, because tracing is disabled. '\
        'Please set `Datadog.configuration.tracing.enabled = true` to continue.'
      )
    end
  end
  "#{Comment.new(tags)} #{sql}"
end