ViewController.swift

//
//  ViewController.swift
//  VideoQuickStart
//
//  Copyright © 2016-2017 Twilio, Inc. All rights reserved.
//

import UIKit

import TwilioVideo

class ViewController: UIViewController {

    // MARK: View Controller Members
    
    // Configure access token manually for testing, if desired! Create one manually in the console
    // at https://www.twilio.com/user/account/video/dev-tools/testing-tools
    var accessToken = "TWILIO_ACCESS_TOKEN"
  
    // Configure remote URL to fetch token from
    var tokenUrl = "http://localhost:8000/token.php"
    
    // Video SDK components
    var room: TVIRoom?
    var camera: TVICameraCapturer?
    var localVideoTrack: TVILocalVideoTrack?
    var localAudioTrack: TVILocalAudioTrack?
    var participant: TVIParticipant?
    var remoteView: TVIVideoView?
    
    // MARK: UI Element Outlets and handles
    
    // `TVIVideoView` created from a storyboard
    @IBOutlet weak var previewView: TVIVideoView!

    @IBOutlet weak var connectButton: UIButton!
    @IBOutlet weak var disconnectButton: UIButton!
    @IBOutlet weak var messageLabel: UILabel!
    @IBOutlet weak var roomTextField: UITextField!
    @IBOutlet weak var roomLine: UIView!
    @IBOutlet weak var roomLabel: UILabel!
    @IBOutlet weak var videoButton: UIButton!

    // MARK: UIViewController
    override func viewDidLoad() {
        super.viewDidLoad()

        if PlatformUtils.isSimulator {
            self.previewView.removeFromSuperview()
        } else {
            // Preview our local camera track in the local video preview view.
            self.startPreview()
        }
        
        // Disconnect and mic button will be displayed when the Client is connected to a Room.
        self.disconnectButton.isHidden = true
        self.videoButton.isHidden = true
        
        self.roomTextField.delegate = self
        
        let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.dismissKeyboard))
        self.view.addGestureRecognizer(tap)
    }
    
    func setupRemoteVideoView() {
        // Creating `TVIVideoView` programmatically
        self.remoteView = TVIVideoView.init(frame: CGRect.zero, delegate:self)
        
        self.view.insertSubview(self.remoteView!, at: 0)
        
        // `TVIVideoView` supports scaleToFill, scaleAspectFill and scaleAspectFit
        // scaleAspectFit is the default mode when you create `TVIVideoView` programmatically.
        self.remoteView!.contentMode = .scaleAspectFit;

        let centerX = NSLayoutConstraint(item: self.remoteView!,
                                         attribute: NSLayoutAttribute.centerX,
                                         relatedBy: NSLayoutRelation.equal,
                                         toItem: self.view,
                                         attribute: NSLayoutAttribute.centerX,
                                         multiplier: 1,
                                         constant: 0);
        self.view.addConstraint(centerX)
        let centerY = NSLayoutConstraint(item: self.remoteView!,
                                         attribute: NSLayoutAttribute.centerY,
                                         relatedBy: NSLayoutRelation.equal,
                                         toItem: self.view,
                                         attribute: NSLayoutAttribute.centerY,
                                         multiplier: 1,
                                         constant: 0);
        self.view.addConstraint(centerY)
        let width = NSLayoutConstraint(item: self.remoteView!,
                                       attribute: NSLayoutAttribute.width,
                                       relatedBy: NSLayoutRelation.equal,
                                       toItem: self.view,
                                       attribute: NSLayoutAttribute.width,
                                       multiplier: 1,
                                       constant: 0);
        self.view.addConstraint(width)
        let height = NSLayoutConstraint(item: self.remoteView!,
                                        attribute: NSLayoutAttribute.height,
                                        relatedBy: NSLayoutRelation.equal,
                                        toItem: self.view,
                                        attribute: NSLayoutAttribute.height,
                                        multiplier: 1,
                                        constant: 0);
        self.view.addConstraint(height)
    }

    // MARK: IBActions
    @IBAction func connect(sender: AnyObject) {
        // Configure access token either from server or manually.
        // If the default wasn't changed, try fetching from server.
        if (accessToken == "TWILIO_ACCESS_TOKEN") {
            do {
                accessToken = try TokenUtils.fetchToken(url: tokenUrl)
            } catch {
                let message = "Failed to fetch access token"
                logMessage(messageText: message)
                return
            }
        }
        
        // Prepare local media which we will share with Room Participants.
        self.prepareLocalMedia()
        
        // Preparing the connect options with the access token that we fetched (or hardcoded).
        let connectOptions = TVIConnectOptions.init(token: accessToken) { (builder) in
            
            // Use the local media that we prepared earlier.
            builder.audioTracks = self.localAudioTrack != nil ? [self.localAudioTrack!] : [TVILocalAudioTrack]()
            builder.videoTracks = self.localVideoTrack != nil ? [self.localVideoTrack!] : [TVILocalVideoTrack]()
            
            // The name of the Room where the Client will attempt to connect to. Please note that if you pass an empty
            // Room `name`, the Client will create one for you. You can get the name or sid from any connected Room.
            builder.roomName = self.roomTextField.text
        }
        
        // Connect to the Room using the options we provided.
        room = TwilioVideo.connect(with: connectOptions, delegate: self)
        
        logMessage(messageText: "Attempting to connect to room \(String(describing: self.roomTextField.text))")
        
        self.showRoomUI(inRoom: true)
        self.dismissKeyboard()
    }
    
    @IBAction func disconnect(sender: AnyObject) {
        self.room!.disconnect()
        logMessage(messageText: "Attempting to disconnect from room \(room!.name)")
    }
    
    @IBAction func toggleVideo(sender: AnyObject) {
        let localParticipator = room?.localParticipant;
        if (localParticipator?.videoTracks.count == 0) {
            self.camera = TVICameraCapturer()
            let constraints = TVIVideoConstraints(block: { (builder: TVIVideoConstraintsBuilder) in
                builder.aspectRatio = TVIAspectRatio16x9
            })
            localVideoTrack = TVILocalVideoTrack(capturer: camera!, enabled: true, constraints: constraints)
            if let unwrVideo = localVideoTrack {
                // localParticipator is obtained from room object
                localParticipator?.addVideoTrack(unwrVideo)
                unwrVideo.addRenderer(self.previewView)
                self.previewView.isHidden = false
                self.videoButton.setTitle("Remove Video", for: .normal)
            }
        } else {
            localParticipator?.removeVideoTrack(localVideoTrack!)
            localVideoTrack?.removeRenderer(self.previewView)
            localVideoTrack = nil
            self.previewView.isHidden = true
            self.videoButton.setTitle("Add Video", for: .normal)
        }
    }

    // MARK: Private
    func startPreview() {
        if PlatformUtils.isSimulator {
            return
        }

        // Preview our local camera track in the local video preview view.
        camera = TVICameraCapturer()
        let constraints = TVIVideoConstraints(block: { (builder: TVIVideoConstraintsBuilder) in
            builder.aspectRatio = TVIAspectRatio16x9
        })
        localVideoTrack = TVILocalVideoTrack(capturer: camera!, enabled: true, constraints: constraints)
        
        if (localVideoTrack == nil) {
            logMessage(messageText: "Failed to create video track")
        } else {
            // Add renderer to video track for local preview
            localVideoTrack!.addRenderer(self.previewView)

            logMessage(messageText: "Video track created")

            // We will flip camera on tap.
            let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.flipCamera))
            self.previewView.addGestureRecognizer(tap)
        }
    }

    func flipCamera() {
        if (self.camera?.source == .frontCamera) {
            self.camera?.selectSource(.backCameraWide)
        } else {
            self.camera?.selectSource(.frontCamera)
        }
    }

    func prepareLocalMedia() {

        // We will share local audio and video when we connect to the Room.

        // Create an audio track.
        if (localAudioTrack == nil) {
            localAudioTrack = TVILocalAudioTrack.init()

            if (localAudioTrack == nil) {
                logMessage(messageText: "Failed to create audio track")
            }
        }

        // Create a video track which captures from the camera.
        if (localVideoTrack == nil) {
            self.startPreview()
        }
    }

    // Update our UI based upon if we are in a Room or not
    func showRoomUI(inRoom: Bool) {
        self.connectButton.isHidden = inRoom
        self.roomTextField.isHidden = inRoom
        self.roomLine.isHidden = inRoom
        self.roomLabel.isHidden = inRoom
        self.videoButton.isHidden = !inRoom
        self.disconnectButton.isHidden = !inRoom
        UIApplication.shared.isIdleTimerDisabled = inRoom
    }
    
    func dismissKeyboard() {
        if (self.roomTextField.isFirstResponder) {
            self.roomTextField.resignFirstResponder()
        }
    }
    
    func cleanupRemoteParticipant() {
        if ((self.participant) != nil) {
            if ((self.participant?.videoTracks.count)! > 0) {
                self.participant?.videoTracks[0].removeRenderer(self.remoteView!)
                self.remoteView?.removeFromSuperview()
                self.remoteView = nil
            }
        }
        self.participant = nil
    }
    
    func logMessage(messageText: String) {
        messageLabel.text = messageText
    }
}

// MARK: UITextFieldDelegate
extension ViewController : UITextFieldDelegate {
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        self.connect(sender: textField)
        return true
    }
}

// MARK: TVIRoomDelegate
extension ViewController : TVIRoomDelegate {
    func didConnect(to room: TVIRoom) {
        
        // At the moment, this example only supports rendering one Participant at a time.
        
        logMessage(messageText: "Connected to room \(room.name) as \(String(describing: room.localParticipant?.identity))")
        
        if (room.participants.count > 0) {
            self.participant = room.participants[0]
            self.participant?.delegate = self
        }
    }
    
    func room(_ room: TVIRoom, didDisconnectWithError error: Error?) {
        logMessage(messageText: "Disconncted from room \(room.name), error = \(String(describing: error))")
        
        self.cleanupRemoteParticipant()
        self.room = nil
        
        self.showRoomUI(inRoom: false)
    }
    
    func room(_ room: TVIRoom, didFailToConnectWithError error: Error) {
        logMessage(messageText: "Failed to connect to room with error")
        self.room = nil
        
        self.showRoomUI(inRoom: false)
    }
    
    func room(_ room: TVIRoom, participantDidConnect participant: TVIParticipant) {
        if (self.participant == nil) {
            self.participant = participant
            self.participant?.delegate = self
        }
       logMessage(messageText: "Room \(room.name), Participant \(participant.identity) connected")
    }
    
    func room(_ room: TVIRoom, participantDidDisconnect participant: TVIParticipant) {
        if (self.participant == participant) {
            cleanupRemoteParticipant()
        }
        logMessage(messageText: "Room \(room.name), Participant \(participant.identity) disconnected")
    }
}

// MARK: TVIParticipantDelegate
extension ViewController : TVIParticipantDelegate {
    func participant(_ participant: TVIParticipant, addedVideoTrack videoTrack: TVIVideoTrack) {
        logMessage(messageText: "Participant \(participant.identity) added video track")

        if (self.participant == participant) {
            setupRemoteVideoView()
            videoTrack.addRenderer(self.remoteView!)
        }
    }
    
    func participant(_ participant: TVIParticipant, removedVideoTrack videoTrack: TVIVideoTrack) {
        logMessage(messageText: "Participant \(participant.identity) removed video track")

        if (self.participant == participant) {
            videoTrack.removeRenderer(self.remoteView!)
            self.remoteView?.removeFromSuperview()
            self.remoteView = nil
        }
    }
    
    func participant(_ participant: TVIParticipant, addedAudioTrack audioTrack: TVIAudioTrack) {
        logMessage(messageText: "Participant \(participant.identity) added audio track")

    }
    
    func participant(_ participant: TVIParticipant, removedAudioTrack audioTrack: TVIAudioTrack) {
        logMessage(messageText: "Participant \(participant.identity) removed audio track")
    }
    
    func participant(_ participant: TVIParticipant, enabledTrack track: TVITrack) {
        var type = ""
        if (track is TVIVideoTrack) {
            type = "video"
        } else {
            type = "audio"
        }
        logMessage(messageText: "Participant \(participant.identity) enabled \(type) track")
    }
    
    func participant(_ participant: TVIParticipant, disabledTrack track: TVITrack) {
        var type = ""
        if (track is TVIVideoTrack) {
            type = "video"
        } else {
            type = "audio"
        }
        logMessage(messageText: "Participant \(participant.identity) disabled \(type) track")
    }
}

// MARK: TVIVideoViewDelegate
extension ViewController : TVIVideoViewDelegate {
    func videoView(_ view: TVIVideoView, videoDimensionsDidChange dimensions: CMVideoDimensions) {
        self.view.setNeedsLayout()
    }
}

// MARK: TVICameraCapturerDelegate
extension ViewController : TVICameraCapturerDelegate {
    func cameraCapturer(_ capturer: TVICameraCapturer, didStartWith source: TVICameraCaptureSource) {
        self.previewView.shouldMirror = (source == .frontCamera)
    }
}