SourceMap.scala

object SourceMap extends Controller {
  implicit val ec = ExecutionContext.global

  def at(prefix: String, path: String) = Action {
    val fileOpt = Play.getExistingFile(s"../$prefix/" + path)

    fileOpt.map {
      case _ if !Play.isDev => Forbidden
      case file if file.isDirectory => NotFound
      case file if !file.exists() => NotFound

      case file =>
        lazy val (length, resourceData) = {
          val stream = new FileInputStream(file)
          try {
            (stream.available, Enumerator.fromStream(stream))
          } catch {
            case NonFatal(_) => (-1, Enumerator[Array[Byte]]())
          }
        }

        if (length == -1) {
          NotFound
        } else {
          Result(
            ResponseHeader(OK, Map(
              CONTENT_LENGTH -> length.toString,
              CONTENT_TYPE -> MimeTypes.forFileName(path).getOrElse(BINARY))),
            resourceData)
        }
    }.getOrElse(NotFound)
  }
}