/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    The extension delegate.

*/

import WatchKit

import WatchConnectivity

class ExtensionDelegate: NSObject, WKExtensionDelegate {

    var wcBackgroundTasks: [WKWatchConnectivityRefreshBackgroundTask]

    override init() {

        wcBackgroundTasks = []

        super.init()

        let defaultSession = WCSession.default()

        defaultSession.delegate = WatchConnectivityManager.sharedConnectivityManager

        /*

         Here we add KVO on the session properties that this class is interested in before activating 

         the session to ensure that we do not miss any value change events

         */

        defaultSession.addObserver(self, forKeyPath: "activationState", options: [], context: nil)

        defaultSession.addObserver(self, forKeyPath: "hasContentPending", options: [], context: nil)

        defaultSession.activate()

    }

    override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        DispatchQueue.main.async {

            self.completeAllTasksIfReady()

        }

    }

    // MARK: Background

    func handle(_ backgroundTasks: Set<WKRefreshBackgroundTask>) {

        for backgroundTask in backgroundTasks {

            if let wcBackgroundTask = backgroundTask as? WKWatchConnectivityRefreshBackgroundTask {

                // store a reference to the task objects as we might have to wait to complete them

                self.wcBackgroundTasks.append(wcBackgroundTask)

            } else {

                // immediately complete all other task types as we have not added support for them

                backgroundTask.setTaskCompleted()

            }

        }

        completeAllTasksIfReady()

    }

    // MARK: Convenience

    func completeAllTasksIfReady() {

        let session = WCSession.default()

        // the session's properties only have valid values if the session is activated, so check that first

        if session.activationState == .activated && !session.hasContentPending {

            wcBackgroundTasks.forEach { $0.setTaskCompleted() }

            wcBackgroundTasks.removeAll()

        }

    }

}