TraceLogging.scala

package unfilteredx.logging

import unfiltered.request._
import unfiltered.response._
import unfiltered.Cycle
import com.typesafe.scalalogging.Logger
import org.slf4j.LoggerFactory

object TraceLogging {
  def apply[A, B](intent: Cycle.Intent[A, B])(implicit tl: TraceLogger[A, B]) =
    Cycle.Intent[A, B] {
      case req =>
        Cycle.Intent.complete(intent)(req) ~> new ResponseFunction[Any]() {
          def apply[C <: Any](resp: HttpResponse[C]) = {
            tl.log(req, resp.asInstanceOf[HttpResponse[B]])
            resp
          }
        }
    }
}

trait TraceLogger[A, B] {
  def log(request: HttpRequest[A], response: HttpResponse[B]): Unit
}

object TraceLogger {
  import unfiltered.netty.ReceivedMessage
  import io.netty.handler.codec.http.{HttpResponse => NettyHttpResponse, DefaultFullHttpResponse, DefaultFullHttpRequest}
  import scala.collection.JavaConverters._
  import java.util.UUID
  import java.nio.charset.StandardCharsets.UTF_8

  implicit object NettyTraceLogger extends TraceLogger[ReceivedMessage, NettyHttpResponse] {
    private val logger = Logger(LoggerFactory.getLogger("request-response"))

    def log(request: HttpRequest[ReceivedMessage], response: HttpResponse[NettyHttpResponse]): Unit = {
      val uuid = UUID.randomUUID().toString
      val baseRequestString = s"$uuid ${request.method} ${request.uri}"
      val requestString = request.underlying.request match {
        case req: DefaultFullHttpRequest => s"$baseRequestString Content=[${req.content().toString(UTF_8)}]"
        case _ => baseRequestString
      }
      logger.debug(requestString)
      
      val baseResponseString = s"$uuid ${response.underlying.getStatus.code()} Headers=[${
        response.underlying.headers().entries().asScala.mkString
      }]"
      val logString = response.underlying match {
        case resp: DefaultFullHttpResponse => s"$baseResponseString Content=[${resp.content().toString(UTF_8)}]"
        case _ => baseResponseString
      }
      
      logger.debug(logString)
      ()
    }
  }
}