func fetch()

in Sources/apm-agent-ios/Configuration/CentralConfigFetcher.swift [128:178]
46 lines of code
11 McCabe index (conditional complexity)

  func fetch() {
    self.task?.cancel()

    if let request = buildCentralConfigRequest() {

      task = URLSession.shared.dataTask(with: request, completionHandler: { data, response, error in
        if let error = error {
          self.logger.error("\(error.localizedDescription)")
          return
        }

        if let response = response as? HTTPURLResponse {
          switch CentralConfigResponse(rawValue: response.statusCode) {
          case .okay:
            if let data = data {

              self.callback(data)

              self.etag = response.allHeaderFields["ETag"] as? String
              if let cacheControl = response.allHeaderFields["Cache-Control"] as? String {
                self.maxAge = Self.parseMaxAge(cacheControl: cacheControl)
              }
            }
          case .forbidden:
            self.logger.debug(
                          """
                          Central configuration is disabled. \
                          Set kibana.enabled: true in your APM Server configuration.
                          """)
          case .notFound:
            self.logger.debug(
                          """
                          This APM Server does not support central configuration. \
                          Update to APM Server 7.3+.
                          """)
          case .notModified:
            self.logger.debug("Central config did not change.")
          case .unavailable:
            self.logger.error(
                          """
                          Remote configuration is not available. \
                          Check the connection between APM Server and Kibana.
                          """)
          default:
            self.logger.error("Unexpected status code (\(response.statusCode)) received.")
          }
        }
      })
      task?.resume()
    }
  }