session-ios/SessionMessagingKit/Calls/WebRTCSession.swift
2022-03-25 13:26:26 +11:00

336 lines
14 KiB
Swift

import PromiseKit
import WebRTC
public protocol WebRTCSessionDelegate : AnyObject {
var videoCapturer: RTCVideoCapturer { get }
func webRTCIsConnected()
func isRemoteVideoDidChange(isEnabled: Bool)
func dataChannelDidOpen()
func didReceiveHangUpSignal()
func reconnectIfNeeded()
}
/// See https://webrtc.org/getting-started/overview for more information.
public final class WebRTCSession : NSObject, RTCPeerConnectionDelegate {
public weak var delegate: WebRTCSessionDelegate?
public let uuid: String
private let contactSessionID: String
private var queuedICECandidates: [RTCIceCandidate] = []
private var iceCandidateSendTimer: Timer?
private lazy var defaultICEServer: TurnServerInfo? = {
let url = Bundle.main.url(forResource: "Session-Turn-Server", withExtension: nil)!
let data = try! Data(contentsOf: url)
let json = try! JSONSerialization.jsonObject(with: data, options: [ .fragmentsAllowed ]) as! JSON
return TurnServerInfo(attributes: json, random: 2)
}()
internal lazy var factory: RTCPeerConnectionFactory = {
RTCInitializeSSL()
let videoEncoderFactory = RTCDefaultVideoEncoderFactory()
let videoDecoderFactory = RTCDefaultVideoDecoderFactory()
return RTCPeerConnectionFactory(encoderFactory: videoEncoderFactory, decoderFactory: videoDecoderFactory)
}()
/// Represents a WebRTC connection between the user and a remote peer. Provides methods to connect to a
/// remote peer, maintain and monitor the connection, and close the connection once it's no longer needed.
internal lazy var peerConnection: RTCPeerConnection = {
let configuration = RTCConfiguration()
if let defaultICEServer = defaultICEServer {
configuration.iceServers = [ RTCIceServer(urlStrings: defaultICEServer.urls, username: defaultICEServer.username, credential: defaultICEServer.password) ]
}
configuration.sdpSemantics = .unifiedPlan
let constraints = RTCMediaConstraints(mandatoryConstraints: [:], optionalConstraints: [:])
return factory.peerConnection(with: configuration, constraints: constraints, delegate: self)
}()
// Audio
internal lazy var audioSource: RTCAudioSource = {
let constraints = RTCMediaConstraints(mandatoryConstraints: [:], optionalConstraints: [:])
return factory.audioSource(with: constraints)
}()
internal lazy var audioTrack: RTCAudioTrack = {
return factory.audioTrack(with: audioSource, trackId: "ARDAMSa0")
}()
// Video
public lazy var localVideoSource: RTCVideoSource = {
let result = factory.videoSource()
result.adaptOutputFormat(toWidth: 360, height: 780, fps: 30)
return result
}()
internal lazy var localVideoTrack: RTCVideoTrack = {
return factory.videoTrack(with: localVideoSource, trackId: "ARDAMSv0")
}()
internal lazy var remoteVideoTrack: RTCVideoTrack? = {
return peerConnection.transceivers.first { $0.mediaType == .video }?.receiver.track as? RTCVideoTrack
}()
// Data Channel
internal var dataChannel: RTCDataChannel?
// MARK: Error
public enum Error : LocalizedError {
case noThread
public var errorDescription: String? {
switch self {
case .noThread: return "Couldn't find thread for contact."
}
}
}
// MARK: Initialization
public static var current: WebRTCSession?
public init(for contactSessionID: String, with uuid: String) {
RTCAudioSession.sharedInstance().useManualAudio = true
RTCAudioSession.sharedInstance().isAudioEnabled = false
self.contactSessionID = contactSessionID
self.uuid = uuid
super.init()
let mediaStreamTrackIDS = ["ARDAMS"]
peerConnection.add(audioTrack, streamIds: mediaStreamTrackIDS)
peerConnection.add(localVideoTrack, streamIds: mediaStreamTrackIDS)
// Configure audio session
configureAudioSession()
// Data channel
if let dataChannel = createDataChannel() {
dataChannel.delegate = self
self.dataChannel = dataChannel
}
}
// MARK: Signaling
public func sendPreOffer(_ message: CallMessage, in thread: TSThread, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
print("[Calls] Sending pre-offer message.")
let (promise, seal) = Promise<Void>.pending()
DispatchQueue.main.async {
MessageSender.sendNonDurably(message, in: thread, using: transaction).done2 {
print("[Calls] Pre-offer message has been sent.")
seal.fulfill(())
}.catch2 { error in
seal.reject(error)
}
}
return promise
}
public func sendOffer(to sessionID: String, using transaction: YapDatabaseReadWriteTransaction, isRestartingICEConnection: Bool = false) -> Promise<Void> {
print("[Calls] Sending offer message.")
guard let thread = TSContactThread.fetch(for: sessionID, using: transaction) else { return Promise(error: Error.noThread) }
let (promise, seal) = Promise<Void>.pending()
peerConnection.offer(for: mediaConstraints(isRestartingICEConnection)) { [weak self] sdp, error in
if let error = error {
seal.reject(error)
} else {
guard let self = self, let sdp = self.correctSessionDescription(sdp: sdp) else { preconditionFailure() }
self.peerConnection.setLocalDescription(sdp) { error in
if let error = error {
print("Couldn't initiate call due to error: \(error).")
return seal.reject(error)
}
}
DispatchQueue.main.async {
let message = CallMessage()
message.sentTimestamp = NSDate.millisecondTimestamp()
message.uuid = self.uuid
message.kind = .offer
message.sdps = [ sdp.sdp ]
MessageSender.sendNonDurably(message, in: thread, using: transaction).done2 {
seal.fulfill(())
}.catch2 { error in
seal.reject(error)
}
}
}
}
return promise
}
public func sendAnswer(to sessionID: String, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
print("[Calls] Sending answer message.")
guard let thread = TSContactThread.fetch(for: sessionID, using: transaction) else { return Promise(error: Error.noThread) }
let (promise, seal) = Promise<Void>.pending()
peerConnection.answer(for: mediaConstraints(false)) { [weak self] sdp, error in
if let error = error {
seal.reject(error)
} else {
guard let self = self, let sdp = self.correctSessionDescription(sdp: sdp) else { preconditionFailure() }
self.peerConnection.setLocalDescription(sdp) { error in
if let error = error {
print("Couldn't accept call due to error: \(error).")
return seal.reject(error)
}
}
DispatchQueue.main.async {
let message = CallMessage()
message.uuid = self.uuid
message.kind = .answer
message.sdps = [ sdp.sdp ]
MessageSender.sendNonDurably(message, in: thread, using: transaction).done2 {
seal.fulfill(())
}.catch2 { error in
seal.reject(error)
}
}
}
}
return promise
}
private func queueICECandidateForSending(_ candidate: RTCIceCandidate) {
queuedICECandidates.append(candidate)
DispatchQueue.main.async {
self.iceCandidateSendTimer?.invalidate()
self.iceCandidateSendTimer = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in
self.sendICECandidates()
}
}
}
private func sendICECandidates() {
Storage.write { transaction in
let candidates = self.queuedICECandidates
guard let thread = TSContactThread.fetch(for: self.contactSessionID, using: transaction) else { return }
print("[Calls] Batch sending \(candidates.count) ICE candidates.")
let message = CallMessage()
let sdps = candidates.map { $0.sdp }
let sdpMLineIndexes = candidates.map { UInt32($0.sdpMLineIndex) }
let sdpMids = candidates.map { $0.sdpMid! }
message.uuid = self.uuid
message.kind = .iceCandidates(sdpMLineIndexes: sdpMLineIndexes, sdpMids: sdpMids)
message.sdps = sdps
self.queuedICECandidates.removeAll()
MessageSender.sendNonDurably(message, in: thread, using: transaction).retainUntilComplete()
}
}
public func endCall(with sessionID: String, using transaction: YapDatabaseReadWriteTransaction) {
guard let thread = TSContactThread.fetch(for: sessionID, using: transaction) else { return }
let message = CallMessage()
message.uuid = self.uuid
message.kind = .endCall
print("[Calls] Sending end call message.")
MessageSender.sendNonDurably(message, in: thread, using: transaction).retainUntilComplete()
}
public func dropConnection() {
peerConnection.close()
}
private func mediaConstraints(_ isRestartingICEConnection: Bool) -> RTCMediaConstraints {
var mandatory: [String:String] = [
kRTCMediaConstraintsOfferToReceiveAudio : kRTCMediaConstraintsValueTrue,
kRTCMediaConstraintsOfferToReceiveVideo : kRTCMediaConstraintsValueTrue,
]
if isRestartingICEConnection { mandatory[kRTCMediaConstraintsIceRestart] = kRTCMediaConstraintsValueTrue }
let optional: [String:String] = [:]
return RTCMediaConstraints(mandatoryConstraints: mandatory, optionalConstraints: optional)
}
private func correctSessionDescription(sdp: RTCSessionDescription?) -> RTCSessionDescription? {
guard let sdp = sdp else { return nil }
let cbrSdp = sdp.sdp.description.replace(regex: "(a=fmtp:111 ((?!cbr=).)*)\r?\n", with: "$1;cbr=1\r\n")
let finalSdp = cbrSdp.replace(regex: ".+urn:ietf:params:rtp-hdrext:ssrc-audio-level.*\r?\n", with: "")
return RTCSessionDescription(type: sdp.type, sdp: finalSdp)
}
// MARK: Peer connection delegate
public func peerConnection(_ peerConnection: RTCPeerConnection, didChange state: RTCSignalingState) {
print("[Calls] Signaling state changed to: \(state).")
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didAdd stream: RTCMediaStream) {
print("[Calls] Peer connection did add stream.")
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didRemove stream: RTCMediaStream) {
print("[Calls] Peer connection did remove stream.")
}
public func peerConnectionShouldNegotiate(_ peerConnection: RTCPeerConnection) {
print("[Calls] Peer connection should negotiate.")
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didChange state: RTCIceConnectionState) {
print("[Calls] ICE connection state changed to: \(state).")
if state == .connected {
delegate?.webRTCIsConnected()
} else if state == .disconnected {
if self.peerConnection.signalingState == .stable {
delegate?.reconnectIfNeeded()
}
}
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didChange state: RTCIceGatheringState) {
print("[Calls] ICE gathering state changed to: \(state).")
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didGenerate candidate: RTCIceCandidate) {
queueICECandidateForSending(candidate)
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didRemove candidates: [RTCIceCandidate]) {
print("[Calls] \(candidates.count) ICE candidate(s) removed.")
}
public func peerConnection(_ peerConnection: RTCPeerConnection, didOpen dataChannel: RTCDataChannel) {
print("[Calls] Data channel opened.")
}
}
extension WebRTCSession {
public func configureAudioSession(outputAudioPort: AVAudioSession.PortOverride = .none) {
let audioSession = RTCAudioSession.sharedInstance()
audioSession.lockForConfiguration()
do {
try audioSession.setCategory(AVAudioSession.Category.playAndRecord.rawValue)
try audioSession.setMode(AVAudioSession.Mode.voiceChat.rawValue)
try audioSession.overrideOutputAudioPort(outputAudioPort)
try audioSession.setActive(true)
} catch let error {
SNLog("Couldn't set up WebRTC audio session due to error: \(error)")
}
audioSession.unlockForConfiguration()
}
public func audioSessionDidActivate(_ audioSession: AVAudioSession) {
RTCAudioSession.sharedInstance().audioSessionDidActivate(audioSession)
RTCAudioSession.sharedInstance().isAudioEnabled = true
configureAudioSession()
}
public func audioSessionDidDeactivate(_ audioSession: AVAudioSession) {
RTCAudioSession.sharedInstance().audioSessionDidDeactivate(audioSession)
RTCAudioSession.sharedInstance().isAudioEnabled = false
}
public func mute() {
audioTrack.isEnabled = false
}
public func unmute() {
audioTrack.isEnabled = true
}
public func turnOffVideo() {
localVideoTrack.isEnabled = false
sendJSON(["video": false])
}
public func turnOnVideo() {
localVideoTrack.isEnabled = true
sendJSON(["video": true])
}
public func hangUp() {
sendJSON(["hangup": true])
}
}