JsonAppendingMarker.scala

package io.airfocus.common.logging

import com.fasterxml.jackson.core.JsonGenerator
import net.logstash.logback.argument.StructuredArgument
import net.logstash.logback.marker.LogstashMarker
import spray.json._

case class JsonAppendingMarker(members: (String, JsValue)*) extends LogstashMarker("JSON_MARKER") with StructuredArgument {
  override def writeTo(generator: JsonGenerator): Unit = {
    def recursion(current: JsValue): Unit = current match {
      case JsObject(fields) =>
        generator.writeStartObject()
        fields.foreach { field =>
          generator.writeFieldName(field._1)
          recursion(field._2)
        }
        generator.writeEndObject()
      case JsArray(items) =>
        generator.writeStartArray()
        items.foreach { item =>
          recursion(item)
        }
        generator.writeEndArray()
      case JsNumber(number) if number.isValidLong =>
        generator.writeNumber(number.toLong)
      case JsNumber(number) =>
        generator.writeNumber(number.toDouble)
      case JsBoolean(boolean) =>
        generator.writeBoolean(boolean)
      case JsString(string) =>
        generator.writeString(string)
      case JsNull =>
        generator.writeNull()
    }

    members.foreach { field =>
      generator.writeFieldName(field._1)
      recursion(field._2)
    }
  }
}