import Combine
import SwiftUI
import UserNotifications
import WatchConnectivity

@main
struct APP: App {
#if os(iOS)
    @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate
#elseif os(watchOS)
    @WKApplicationDelegateAdaptor(AppDelegate.self) var delegate
#endif
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

struct ContentView: View {
    @EnvironmentObject var appDelegate: AppDelegate
    var body: some View {
        Button("Notify") {
            Task {
                let id = UUID().uuidString
                await self.appDelegate.callNotification(id: id)
                WCSession.default.sendMessage(["id" : id], replyHandler: nil)
            }
        }
    }
}

@MainActor
class AppDelegate: NSObject,
                   ObservableObject,
                   @preconcurrency UNUserNotificationCenterDelegate,
                   @preconcurrency WCSessionDelegate {
    
    func callNotification(id: String) async {
        try! await UNUserNotificationCenter.current()
            .add(
                .init(
                    identifier: id,
                    content: {
                        let value = UNMutableNotificationContent()
#if os(iOS)
                        value.title += "Hello for iOS"
#elseif os(watchOS)
                        value.title += "Hello for watchOS"
#endif
                        value.body = "id: " + id
                        value.sound = .default
                        return value
                    }(),
                    trigger: UNTimeIntervalNotificationTrigger(timeInterval: 0.1,
                                                               repeats: false)
                )
            )
    }
    
    func session(_ session: WCSession, didReceiveMessage message: [String : Any]) {
        Task { @MainActor in
            await self.callNotification(id: message["id"]! as! String)
        }
    }
    
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([.banner, .list, .sound])
    }
    
    override init() {
        super.init()
        let wcSession = WCSession.default
        wcSession.delegate = self
        wcSession.activate()
        let userNotificationCenter = UNUserNotificationCenter.current()
        userNotificationCenter.delegate = self
        Task {
            try! await userNotificationCenter.requestAuthorization(options: [.alert, .badge, .sound])
        }
    }
    
    func session(_ session: WCSession,
                 activationDidCompleteWith activationState: WCSessionActivationState,
                 error: (any Error)?) {}
#if os(iOS)
    func sessionDidBecomeInactive(_ session: WCSession) {}
    func sessionDidDeactivate(_ session: WCSession) {}
#endif
}

#if os(iOS)
extension AppDelegate: UIApplicationDelegate {}
#elseif os(watchOS)
extension AppDelegate: WKApplicationDelegate {}
#endif