[SwiftUI][watchOS] Timer アプリを AppleWatch 向けに作る(その２ Haptic 追加） 当面、凍結

func play(_ type: WKHapticType)

//
//  MultiTimerViewModel.swift
//
//  Created by : Tomoaki Yagishita on 2020/11/16
//  © 2020  SmallDeskSoftware
//

import Foundation
import Combine
import SwiftUI
import os
import WatchKit
import UserNotifications

class MultiTimerViewModel: NSObject, ObservableObject {
    @Published var multiTimerModel: MultiTimerModel = MultiTimerModel()
    @Published var remainSec:Int = 0
    
    let logger = Logger(subsystem: "com.smalldesksoftware.multitimer.TimerViewModel", category: "viewmodel")
    
    // haptic type
    let startHaptic: WKHapticType = .start
    let stopHaptic: WKHapticType = .stop

    var cancellable: Cancellable?

    var isIdle: Bool {
        return multiTimerModel.startDate == nil
    }

    func start() {
        logger.debug("timer start called")
        self.multiTimerModel.startDate = Date()
        cancellable?.cancel()
        self.cancellable = Timer.publish(every: 1, on: .main, in: .common)
            .autoconnect()
            .sink() { date in
                self.updateRemainSec(date)
            }
        // (1)
        WKInterfaceDevice.current().play(startHaptic)
    }
    
    func stop() {
        logger.debug("timer stop called")
        self.multiTimerModel.startDate = nil
        self.cancellable?.cancel()
        self.cancellable = nil
        self.remainSec = 0
        // (2)
        WKInterfaceDevice.current().play(stopHaptic)
    }

    func updateRemainSec(_ date:Date) {
        guard let sec = self.multiTimerModel.remainSec(date) else { return }
        logger.debug("remain sec: \(sec)")
        self.remainSec = sec
        
        if sec > 0 {
            return
        }
        
        self.remainSec = 0
        self.stop()
    }
    
    func remainSecAsString() -> String {
        if remainSec = 0 { return String(multiTimerModel.duration) }
        return String(remainSec)
    }
}

    func start() {
        logger.info("timer start called")
        self.timerModel.startDate = Date()
        cancellable?.cancel()
        self.cancellable = Timer.publish(every: 1, on: .main, in: .common)
            .autoconnect()
            .sink() { date in
                self.updateRemainSec(date)
            }
        WKInterfaceDevice.current().play(timerModel.startHaptic)
        scheduleBackgroundTask()
    }

    fileprivate func scheduleBackgroundTask() {
        self.logger.debug("schedule background task remain")
        let nextUpdateDate = Date(timeIntervalSinceNow: Double(self.multiTimerModel.duration))
        WKExtension.shared().scheduleBackgroundRefresh(withPreferredDate: nextUpdateDate, userInfo: nil) { (error) in
            if (error != nil) {
                self.logger.error("failed to schedule in scheduleBackgroundRefresh")
            }
        }
    }

extension MultiTimerViewModel: WKExtensionDelegate {
    func handle(_ backgroundTasks: Set) {
        logger.debug("# of task is \(backgroundTasks.count)")
        self.updateRemainSec(Date())
        for task in backgroundTasks {
            // task might be WKApplicationRefreshBackgroundTask,WKSnapshotRefreshBackgroundTask or  others, anyway need to handle.
            if task.isKind(of: WKSnapshotRefreshBackgroundTask.self) {
                task.setTaskCompletedWithSnapshot(true)
            } else {
                task.setTaskCompletedWithSnapshot(false)
            }
        }
    }
}

//
//  MultiTimerApp.swift
//
//  Created by : Tomoaki Yagishita on 2020/11/16
//  © 2020  SmallDeskSoftware
//

import SwiftUI
import os

@main
struct MultiTimerApp: App {
    // (NEW) specify WKExtensionDelegate
    @WKExtensionDelegateAdaptor(MultiTimerViewModel.self) var delegate 
    @StateObject var multiTimerViewModel: MultiTimerViewModel = MultiTimerViewModel()

    let logger = Logger(subsystem: "com.smalldesksoftware.multitimer.TimerApp", category: "app")

    @SceneBuilder var body: some Scene {
        WindowGroup {
            NavigationView {
                MultiTimerView(multiTimerViewModel: multiTimerViewModel)
            }
        }
        WKNotificationScene(controller: NotificationController.self, category: "myCategory")
    }
}