iOS setup

<key>UIBackgroundModes</key>
<array>
    <string>voip</string>
    <string>remote-notification</string>
    <string>processing</string> <!-- add this if needed -->
</array>

ios: IOSParams(
  iconName: 'CallKitLogo', // matches the name in Images.xcassets
),

import UIKit
import CallKit
import AVFAudio
import PushKit
import Flutter
import flutter_callkit_incoming

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate, PKPushRegistryDelegate, CallkitIncomingAppDelegate {

    override func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        GeneratedPluginRegistrant.register(with: self)

        // Setup VOIP
        let mainQueue = DispatchQueue.main
        let voipRegistry: PKPushRegistry = PKPushRegistry(queue: mainQueue)
        voipRegistry.delegate = self
        voipRegistry.desiredPushTypes = [PKPushType.voIP]

        // Use if using WebRTC
        // RTCAudioSession.sharedInstance().useManualAudio = true
        // RTCAudioSession.sharedInstance().isAudioEnabled = false

        // Add for Missed call notification
        if #available(iOS 10.0, *) {
            UNUserNotificationCenter.current().delegate = self as UNUserNotificationCenterDelegate
        }

        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }

    // Handle updated push credentials
    func pushRegistry(_ registry: PKPushRegistry, didUpdate credentials: PKPushCredentials, for type: PKPushType) {
        print(credentials.token)
        let deviceToken = credentials.token.map { String(format: "%02x", $0) }.joined()
        // Save deviceToken to your server
        SwiftFlutterCallkitIncomingPlugin.sharedInstance?.setDevicePushTokenVoIP(deviceToken)
    }

    func pushRegistry(_ registry: PKPushRegistry, didInvalidatePushTokenFor type: PKPushType) {
        print("didInvalidatePushTokenFor")
        SwiftFlutterCallkitIncomingPlugin.sharedInstance?.setDevicePushTokenVoIP("")
    }

    // Handle incoming VoIP pushes
    func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {
        print("didReceiveIncomingPushWith")
        guard type == .voIP else { return }

        let id = payload.dictionaryPayload["id"] as? String ?? ""
        let nameCaller = payload.dictionaryPayload["nameCaller"] as? String ?? ""
        let handle = payload.dictionaryPayload["handle"] as? String ?? ""
        let isVideo = payload.dictionaryPayload["isVideo"] as? Bool ?? false

        let data = flutter_callkit_incoming.Data(id: id, nameCaller: nameCaller, handle: handle, type: isVideo ? 1 : 0)
        // Set more data as needed
        // data.extra = ["user": "abc@123", "platform": "ios"]
        SwiftFlutterCallkitIncomingPlugin.sharedInstance?.showCallkitIncoming(data, fromPushKit: true) {
            completion()
        }
    }

    // Called when the user accepts a call
    func onAccept(_ call: Call, _ action: CXAnswerCallAction) {
        let json = ["action": "ACCEPT", "data": call.data.toJSON()] as [String: Any]
        print("LOG: onAccept")
        // Perform your API call here, then call action.fulfill() when done
        // (e.g., when WebRTC connection is established)
        action.fulfill()
    }

    // Called when the user declines a call
    func onDecline(_ call: Call, _ action: CXEndCallAction) {
        let json = ["action": "DECLINE", "data": call.data.toJSON()] as [String: Any]
        print("LOG: onDecline")
        // Perform your API call here, then call action.fulfill() when done
        action.fulfill()
    }

    // Called when the user ends a call
    func onEnd(_ call: Call, _ action: CXEndCallAction) {
        let json = ["action": "END", "data": call.data.toJSON()] as [String: Any]
        print("LOG: onEnd")
        // Perform your API call here, then call action.fulfill() when done
        action.fulfill()
    }

    // Called when the incoming call times out (missed)
    func onTimeOut(_ call: Call) {
        let json = ["action": "TIMEOUT", "data": call.data.toJSON()] as [String: Any]
        print("LOG: onTimeOut")
    }

    // Called when the audio session is activated (e.g., call accepted)
    func didActivateAudioSession(_ audioSession: AVAudioSession) {
        // Use if using WebRTC:
        // RTCAudioSession.sharedInstance().audioSessionDidActivate(audioSession)
        // RTCAudioSession.sharedInstance().isAudioEnabled = true
    }

    // Called when the audio session is deactivated (e.g., call ended)
    func didDeactivateAudioSession(_ audioSession: AVAudioSession) {
        // Use if using WebRTC:
        // RTCAudioSession.sharedInstance().audioSessionDidDeactivate(audioSession)
        // RTCAudioSession.sharedInstance().isAudioEnabled = false
    }
}

// Show notification when app is in the foreground
override func userNotificationCenter(_ center: UNUserNotificationCenter,
                                     willPresent notification: UNNotification,
                                     withCompletionHandler completionHandler:
                                     @escaping (UNNotificationPresentationOptions) -> Void) {

    CallkitNotificationManager.shared.userNotificationCenter(center, willPresent: notification, withCompletionHandler: completionHandler)
}

// Handle callback action tapped in a missed call notification
override func userNotificationCenter(_ center: UNUserNotificationCenter,
                                     didReceive response: UNNotificationResponse,
                                     withCompletionHandler completionHandler: @escaping () -> Void) {
    if response.actionIdentifier == CallkitNotificationManager.CALLBACK_ACTION {
        let data = response.notification.request.content.userInfo as? [String: Any]
        SwiftFlutterCallkitIncomingPlugin.sharedInstance?.sendCallbackEvent(data)
    }
    completionHandler()
}