import UIKit
import ARKit
import AgoraRtcEngineKit


class ViewController: UIViewController {

    @IBOutlet weak var stackView: UIStackView!

    var agoraKit: AgoraRtcEngineKit!

    var tags: [Int] = (1...100).map { $0 }

    var sceneView: ARSCNView?

    let noseOptions = ["👃", "🐽", "💧", " "]

    var isARSupported: Bool {
        return ARFaceTrackingConfiguration.isSupported
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        initializeAgoraEngine()
        setupVideo()
        setChannelProfile()
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        showJoinAlert()
    }

    func showJoinAlert() {
        let alertController = UIAlertController(title: nil, message: "Ready to join channel.", preferredStyle: .alert)

        let action = UIAlertAction(title: "Join", style: .destructive) { (action:UIAlertAction) in
            self.joinChannel()
        }
        alertController.addAction(action)
        present(alertController, animated: true, completion: nil)
    }

    func initializeAgoraEngine() {
        agoraKit = AgoraRtcEngineKit.sharedEngine(withAppId: AppID, delegate: self)
    }

    func setChannelProfile() {
        agoraKit.setChannelProfile(.communication)
    }

    func setupVideo() {
        agoraKit.enableVideo()
        agoraKit.setVideoEncoderConfiguration(
            AgoraVideoEncoderConfiguration(size: AgoraVideoDimension640x360,
                                           frameRate: .fps15,
                                           bitrate: AgoraVideoBitrateStandard,
                                           orientationMode: .adaptative)
        )
    }

    func joinChannel() {
        agoraKit.setDefaultAudioRouteToSpeakerphone(true)

        guard let uid = tags.randomElement() else { return }

        agoraKit.joinChannel(byToken: nil,
                             channelId: "DemoChannel",
                             info: nil,
                             uid: UInt(uid)) { [weak self] (sid, uid, elapsed) -> Void in

            guard let _self = self else { return }
            DispatchQueue.main.async {
                _self.setupLocalVideo(uid: uid)
            }

        }
        UIApplication.shared.isIdleTimerDisabled = true
    }

    func setupLocalVideo(uid: UInt) {


        let videoView = ARSCNView()
        videoView.tag = Int(uid)
        videoView.backgroundColor = UIColor.orange

//        let videoCanvas = AgoraRtcVideoCanvas()
//        videoCanvas.uid = uid
//        videoCanvas.view = videoView
//        videoCanvas.renderMode = .hidden
//        agoraKit.setupLocalVideo(videoCanvas)

        self.sceneView = videoView
        self.sceneView?.delegate = self

        if isARSupported {
            let configuration = ARFaceTrackingConfiguration()
            sceneView?.session.run(configuration)
        }

        let tapGuesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(_:)))
        tapGuesture.numberOfTapsRequired = 1
        self.sceneView?.addGestureRecognizer(tapGuesture)

        stackView.addArrangedSubview(videoView)
    }

    @IBAction func didClickHangUpButton(_ sender: UIButton) {
        leaveChannel()
    }

    func leaveChannel() {
        agoraKit.leaveChannel(nil)
        UIApplication.shared.isIdleTimerDisabled = false
    }

    @IBAction func didClickMuteButton(_ sender: UIButton) {
        sender.isSelected = !sender.isSelected
        agoraKit.muteLocalAudioStream(sender.isSelected)
    }

    func updateFeatures(for node: SCNNode, using anchor: ARFaceAnchor) {

        let child = node.childNode(withName: "nose", recursively: false) as? EmojiNode

        let vertices = [anchor.geometry.vertices[9]]

        child?.updatePosition(for: vertices)
    }

    @IBAction func handleTap(_ sender: UITapGestureRecognizer) {
        let location = sender.location(in: sceneView)
        let results = sceneView?.hitTest(location, options: nil)
        if let result = results?.first,
            let node = result.node as? EmojiNode {
            node.next()
        }
    }
}

extension ViewController: AgoraRtcEngineDelegate {

    func rtcEngine(_ engine: AgoraRtcEngineKit, firstRemoteVideoDecodedOfUid uid:UInt, size:CGSize, elapsed:Int) {

        let videoView = UIView()
        videoView.tag = Int(uid)
        videoView.backgroundColor = UIColor.purple
        stackView.addArrangedSubview(videoView)

        let videoCanvas = AgoraRtcVideoCanvas()
        videoCanvas.uid = uid
        videoCanvas.view = videoView
        videoCanvas.renderMode = .hidden
        agoraKit.setupRemoteVideo(videoCanvas)
    }

    internal func rtcEngine(_ engine: AgoraRtcEngineKit, didOfflineOfUid uid:UInt, reason:AgoraUserOfflineReason) {

        guard let view = stackView.arrangedSubviews.first(where: { (view) -> Bool in
            return view.tag == Int(uid)
        }) else { return }

        stackView.removeArrangedSubview(view)
    }

    func rtcEngine(_ engine: AgoraRtcEngineKit, didVideoMuted muted:Bool, byUid:UInt) {
//        remoteVideoMutedIndicator.isHidden = !muted
    }
}

extension ViewController: ARSCNViewDelegate {

    func renderer(_ renderer: SCNSceneRenderer, nodeFor anchor: ARAnchor) -> SCNNode? {

        guard let faceAnchor = anchor as? ARFaceAnchor,
            let device = sceneView?.device else { return nil }

        let faceGeometry = ARSCNFaceGeometry(device: device)

        let node = SCNNode(geometry: faceGeometry)

        node.geometry?.firstMaterial?.fillMode = .lines

        node.geometry?.firstMaterial?.transparency = 0.0
        let noseNode = EmojiNode(with: noseOptions)
        noseNode.name = "nose"
        node.addChildNode(noseNode)

        updateFeatures(for: node, using: faceAnchor)
        return node
    }

    func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) {

        guard let faceAnchor = anchor as? ARFaceAnchor,
            let faceGeometry = node.geometry as? ARSCNFaceGeometry else {
                return
        }

        faceGeometry.update(from: faceAnchor.geometry)
    }
}