// If you want to use the multi-camera feature, please make sure stream.isMultiCamSessionEnabled = true. Before attachCamera or attachAudio.
stream.isMultiCamSessionEnabled = true

let back = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back)
stream.attachCamera(back, track: 0) { _, error in
  if let error {
    logger.warn(error)
  }
}

let front = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front)
stream.attachCamera(front, track: 1) { videoUnit, error in
  videoUnit?.isVideoMirrored = true
  if let error {
    logger.error(error)
  }
}

import AVFoundation
let session = AVAudioSession.sharedInstance()
do {
    try session.setCategory(.playAndRecord, mode: .default, options: [.defaultToSpeaker, .allowBluetooth])
    try session.setActive(true)
} catch {
    print(error)
}

let connection = RTMPConnection()
let stream = RTMPStream(connection: connection)

stream.attachAudio(AVCaptureDevice.default(for: .audio)) { _, error in
  if let error {
    logger.warn(error)
  }
}

stream.attachCamera(AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back), track: 0) { _, error in
  if let error {
    logger.warn(error)
  }
}

let hkView = MTHKView(frame: view.bounds)
hkView.videoGravity = AVLayerVideoGravity.resizeAspectFill
hkView.attachStream(stream)

// add ViewController#view
view.addSubview(hkView)

connection.connect("rtmp:https://localhost/appName/instanceName")
stream.publish("streamName")

let connection = RTMPConnection()
let stream = RTMPStream(connection: connection)

let hkView = MTHKView(frame: view.bounds)
hkView.videoGravity = AVLayerVideoGravity.resizeAspectFill
hkView.attachStream(stream)

// add ViewController#view
view.addSubview(hkView)

connection.connect("rtmp:https://localhost/appName/instanceName")
stream.play("streamName")

var connection = RTMPConnection()
connection.connect("rtmp:https://username:password@localhost/appName/instanceName")

let connection = SRTConnection()
let stream = SRTStream(connection: connection)
stream.attachAudio(AVCaptureDevice.default(for: .audio)) { error in
    // print(error)
}
stream.attachCamera(AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back), track: 0) { _, error in
  if let error {
    logger.warn(error)
  }
}

let hkView = HKView(frame: view.bounds)
hkView.videoGravity = AVLayerVideoGravity.resizeAspectFill
hkView.attachStream(rtmpStream)

// add ViewController#view
view.addSubview(hkView)

connection.connect("srt:https://host:port?option=foo")
stream.publish()

let connection = SRTConnection()
let stream = SRTStream(connection: connection)

let hkView = MTHKView(frame: view.bounds)
hkView.videoGravity = AVLayerVideoGravity.resizeAspectFill
hkView.attachStream(rtmpStream)

// add ViewController#view
view.addSubview(hkView)

connection.connect("srt:https://host:port?option=foo")
stream.play()

stream.frameRate = 30
stream.sessionPreset = AVCaptureSession.Preset.medium

// Do not call beginConfiguration() and commitConfiguration() internally within the scope of the method, as they are called internally.
stream.configuration { session in
  session.automaticallyConfiguresApplicationAudioSession = true
}

let front = AVCaptureDevice.default(for: .audio)
stream.attachAudio(front, track: 0) { audioUnit, error in
}

FeatureUtil.setEnabled(for: .multiTrackAudioMixing, isEnabled: true)

// Setting the value to 0 will be the same as the value specified in mainTrack.
stream.audioMixerSettings = IOAudioMixerSettings(
  sampleRate: Float64 = 44100,
  channels: UInt32 = 0,
)

stream.audioMixerSettings.isMuted = false
stream.audioMixerSettings.mainTrack = 0
stream.audioMixerSettings.tracks = [
  0: .init(
    isMuted: Bool = false,
    downmix: Bool = true,
    channelMap: [Int]? = nil
  )
]

/// Specifies the bitRate of audio output.
stream.audioSettings.bitrate = 64 * 1000
/// Specifies the mixes the channels or not. Currently, it supports input sources with 4, 5, 6, and 8 channels.
stream.audioSettings.downmix = true
/// Specifies the map of the output to input channels.
 stream.audioSettings.channelMap: [Int]? = nil

let front = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front)
stream.attachCamera(front, track: 0) { videoUnit, error in
  videoUnit?.isVideoMirrored = true
  videoUnit?.preferredVideoStabilizationMode = .standard
  videoUnit?.colorFormat = kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange
}

stream.videoMixerSettings = IOVideoMixerSettings(
  mode: .pip,
  cornerRadius: 16.0,
  regionOfInterest: .init(
    origin: CGPoint(x: 16, y: 16),
    size: .init(width: 160, height: 160)
  ),
  direction: .east
)

stream.videoSettings = .init(
  videoSize: .init(width: 854, height: 480),
  profileLevel: kVTProfileLevel_H264_Baseline_3_1 as String,
  bitRate: 640 * 1000,
  maxKeyFrameIntervalDuration: 2,
  scalingMode: .trim,
  bitRateMode: .average,
  allowFrameReordering: nil,
  isHardwareEncoderEnabled: true
)

let channels = max(stream.audioInputFormats[0].channels ?? 1, 2)
stream.audioMixerSettings = .init(sampleRate: 0, channels: channels)

// Specifies the recording settings. 0" means the same of input.
var recorder = IOStreamRecorder()
stream.addObserver(recorder)

recorder.settings = [
  AVMediaType.audio: [
    AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
    AVSampleRateKey: 0,
    AVNumberOfChannelsKey: 0,
    // AVEncoderBitRateKey: 128000,
  ],
  AVMediaType.video: [
    AVVideoCodecKey: AVVideoCodecH264,
    AVVideoHeightKey: 0,
    AVVideoWidthKey: 0,
    /*
    AVVideoCompressionPropertiesKey: [
      AVVideoMaxKeyFrameIntervalDurationKey: 2,
      AVVideoProfileLevelKey: AVVideoProfileLevelH264Baseline30,
      AVVideoAverageBitRateKey: 512000
    ]
    */
  ]
]

recorder.startRunning()
// recorder.stopRunning()