Files
letro-ios/ElementX/Sources/Screens/CallScreen/CallScreenViewModel.swift

263 lines
11 KiB
Swift

//
// Copyright 2022 New Vector Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
import AVKit
import CallKit
import Combine
import SwiftUI
typealias CallScreenViewModelType = StateStoreViewModel<CallScreenViewState, CallScreenViewAction>
class CallScreenViewModel: CallScreenViewModelType, CallScreenViewModelProtocol {
private let elementCallService: ElementCallServiceProtocol
private let configuration: ElementCallConfiguration
private let isPictureInPictureAllowed: Bool
private let widgetDriver: ElementCallWidgetDriverProtocol
private let actionsSubject: PassthroughSubject<CallScreenViewModelAction, Never> = .init()
var actions: AnyPublisher<CallScreenViewModelAction, Never> {
actionsSubject.eraseToAnyPublisher()
}
private var syncUpdateCancellable: AnyCancellable?
/// Designated initialiser
/// - Parameters:
/// - elementCallService: service responsible for setting up CallKit
/// - roomProxy: The room in which the call should be created
/// - callBaseURL: Which Element Call instance should be used
/// - clientID: Something to identify the current client on the Element Call side
init(elementCallService: ElementCallServiceProtocol,
configuration: ElementCallConfiguration,
allowPictureInPicture: Bool,
appHooks: AppHooks) {
self.elementCallService = elementCallService
self.configuration = configuration
isPictureInPictureAllowed = allowPictureInPicture
switch configuration.kind {
case .genericCallLink(let url):
widgetDriver = GenericCallLinkWidgetDriver(url: url)
case .roomCall(let roomProxy, let clientProxy, _, _, _, _):
guard let deviceID = clientProxy.deviceID else { fatalError("Missing device ID for the call.") }
widgetDriver = roomProxy.elementCallWidgetDriver(deviceID: deviceID)
}
super.init(initialViewState: CallScreenViewState(messageHandler: Self.eventHandlerName,
script: Self.eventHandlerInjectionScript,
certificateValidator: appHooks.certificateValidatorHook))
state.bindings.javaScriptMessageHandler = { [weak self] message in
guard let self, let message = message as? String else { return }
Task { await self.widgetDriver.handleMessage(message) }
}
elementCallService.actions
.receive(on: DispatchQueue.main)
.sink { [weak self] action in
guard let self else { return }
switch action {
case let .setAudioEnabled(enabled, roomID):
guard roomID == configuration.callRoomID else {
MXLog.error("Received mute request for a different room: \(roomID) != \(configuration.callRoomID)")
return
}
Task {
await self.setAudioEnabled(enabled)
}
default:
break
}
}
.store(in: &cancellables)
widgetDriver.messagePublisher
.receive(on: DispatchQueue.main)
.sink { [weak self] receivedMessage in
guard let self else { return }
Task {
await self.postJSONToWidget(receivedMessage)
}
}
.store(in: &cancellables)
widgetDriver.actions
.receive(on: DispatchQueue.main)
.sink { [weak self] action in
guard let self else { return }
switch action {
case .callEnded:
actionsSubject.send(.dismiss)
case .mediaStateChanged(let audioEnabled, _):
elementCallService.setAudioEnabled(audioEnabled, roomID: configuration.callRoomID)
}
}
.store(in: &cancellables)
setupCall()
}
override func process(viewAction: CallScreenViewAction) {
switch viewAction {
case .urlChanged(let url):
guard let url else { return }
MXLog.info("URL changed to: \(url)")
case .navigateBack:
Task { await handleBackwardsNavigation() }
case .pictureInPictureWillStop:
actionsSubject.send(.pictureInPictureStopped)
case .endCall:
actionsSubject.send(.dismiss)
}
}
func stop() {
Task {
await hangup()
}
elementCallService.tearDownCallSession()
}
// MARK: - Private
private func setupCall() {
switch configuration.kind {
case .genericCallLink(let url):
state.url = url
// We need widget messaging to work before enabling CallKit, otherwise mute, hangup etc do nothing.
case .roomCall(let roomProxy, let clientProxy, let clientID, let elementCallBaseURL, let elementCallBaseURLOverride, let colorScheme):
// Wait for room states to be up to date before starting the call and notifying others
syncUpdateCancellable = clientProxy.actionsPublisher
.filter(\.isSyncUpdate)
.timeout(.seconds(5), scheduler: DispatchQueue.main)
.first() // Timeout will make the publisher complete, use first to handle both branches in the same place
.sink(receiveCompletion: { [weak self] _ in
Task { [weak self] in
guard let self else { return }
let baseURL = if let elementCallBaseURLOverride {
elementCallBaseURLOverride
} else if case .success(let wellKnown) = await clientProxy.getElementWellKnown(), let wellKnownCall = wellKnown?.call {
wellKnownCall.widgetURL
} else {
elementCallBaseURL
}
switch await widgetDriver.start(baseURL: baseURL, clientID: clientID, colorScheme: colorScheme) {
case .success(let url):
state.url = url
case .failure(let error):
MXLog.error("Failed starting ElementCall Widget Driver with error: \(error)")
state.bindings.alertInfo = .init(id: UUID(),
title: L10n.errorUnknown,
primaryButton: .init(title: L10n.actionOk) {
self.actionsSubject.send(.dismiss)
})
return
}
await elementCallService.setupCallSession(roomID: roomProxy.id, roomDisplayName: roomProxy.roomTitle)
_ = await roomProxy.sendCallNotificationIfNeeded()
syncUpdateCancellable = nil
}
}, receiveValue: { _ in })
}
}
private func handleBackwardsNavigation() async {
guard state.url != nil,
isPictureInPictureAllowed,
let requestPictureInPictureHandler = state.bindings.requestPictureInPictureHandler else {
actionsSubject.send(.dismiss)
return
}
switch await requestPictureInPictureHandler() {
case .success(let controller):
actionsSubject.send(.pictureInPictureStarted(controller))
case .failure:
actionsSubject.send(.dismiss)
}
}
private func setAudioEnabled(_ enabled: Bool) async {
let message = ElementCallWidgetMessage(direction: .toWidget,
action: .mediaState,
data: .init(audioEnabled: enabled),
widgetId: widgetDriver.widgetID)
await postMessageToWidget(message)
}
func hangup() async {
let message = ElementCallWidgetMessage(direction: .fromWidget,
action: .hangup,
widgetId: widgetDriver.widgetID)
await postMessageToWidget(message)
}
private func postMessageToWidget(_ message: ElementCallWidgetMessage) async {
do {
let data = try JSONEncoder().encode(message)
let json = String(decoding: data, as: UTF8.self)
await postJSONToWidget(json)
} catch {
MXLog.error("Failed encoding widget message with error: \(error)")
}
}
private func postJSONToWidget(_ json: String) async {
do {
let message = "postMessage(\(json), '*')"
let result = try await state.bindings.javaScriptEvaluator?(message)
MXLog.debug("Evaluated javascript: \(json) with result: \(String(describing: result))")
} catch {
MXLog.error("Received javascript evaluation error: \(error)")
}
}
private static let eventHandlerName = "elementx"
private static var eventHandlerInjectionScript: String {
"""
window.addEventListener(
"message",
(event) => {
let message = {data: event.data, origin: event.origin}
if (message.data.response && message.data.api == "toWidget"
|| !message.data.response && message.data.api == "fromWidget") {
window.webkit.messageHandlers.\(eventHandlerName).postMessage(JSON.stringify(message.data));
}else{
console.log("-- skipped event handling by the client because it is send from the client itself.");
}
},
false,
);
"""
}
}