import AVKit
import React

@available(iOS 11.0, *)
@objc(RAExternalPlaybackAvailabilityContext)
class RAExternalPlaybackAvailabilityContext: RAEventEmitter {
  private let avRouteDetector = AVRouteDetector()

  override func startObserving() {
    super.startObserving()
    avRouteDetector.isRouteDetectionEnabled = true

    NotificationCenter
      .default
      .addObserver(
        self,
        selector: #selector(handleMultipleRoutesDetectedDidChange),
        name: NSNotification.Name.AVRouteDetectorMultipleRoutesDetectedDidChange,
        object: nil)
  }

  override func stopObserving() {
    super.stopObserving()
    avRouteDetector.isRouteDetectionEnabled = false
    NotificationCenter.default.removeObserver(self)
  }

  override func supportedEvents() -> [String]! {
    return [RAEvent.externalPlaybackAvailabilityChanged.rawValue]
  }

  @objc override class func requiresMainQueueSetup() -> Bool {
    return false
  }

  @objc(fetchExternalPlaybackAvailabilityWithResolver:rejecter:)
  func fetchExternalPlaybackAvailability(
    resolver resolve: RCTPromiseResolveBlock,
    rejecter reject: RCTPromiseRejectBlock
  ) {
    resolve(getExternalPlaybackAvailability())
  }

  private func getExternalPlaybackAvailability() -> Bool {
    return avRouteDetector.multipleRoutesDetected
  }

  @objc private func handleMultipleRoutesDetectedDidChange() {
    sendEvent(
      withName: RAEvent.externalPlaybackAvailabilityChanged.rawValue,
      body: avRouteDetector.multipleRoutesDetected)
  }
}