space-ios/Notification Service Extension/NotificationService.swift

//
//  NotificationService.swift
//  Notification Service Extension
//
//  Created by Marino Faggiana on 27/07/18.
//  Copyright © 2018 Marino Faggiana. All rights reserved.
//
//  Author Marino Faggiana <m.faggiana@twsweb.it>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

import UserNotifications

class NotificationService: UNNotificationServiceExtension {

    let privateKey = CCUtility.getPushNotificationPrivateKey()
    var contentHandler: ((UNNotificationContent) -> Void)?
    var bestAttemptContent: UNMutableNotificationContent?

    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        
        if let bestAttemptContent = bestAttemptContent {

            bestAttemptContent.title = ""
            bestAttemptContent.body = "Nextcloud notification"
            
            let message = bestAttemptContent.userInfo["subject"] as! String
            
            guard let privateKey = CCUtility.getPushNotificationPrivateKey() else {
                contentHandler(bestAttemptContent)
                return
            }
            
            guard let decryptedMessage = NCPushNotificationEncryption.sharedInstance().decryptPushNotification(message, withDevicePrivateKey: privateKey) else {
                contentHandler(bestAttemptContent)
                return
            }
            
            guard let data = decryptedMessage.data(using: .utf8) else {
                contentHandler(bestAttemptContent)
                return
            }
            
            do {
                let json = try JSONSerialization.jsonObject(with: data) as! [String:AnyObject]
                if let app = json["app"] as? String {
                    if app == "spreed" {
                        bestAttemptContent.title = "Nextcloud Talk"
                    } else {
                        bestAttemptContent.title = app.capitalized
                    }
                }
                if let subject = json["subject"] as? String {
                    bestAttemptContent.body = subject
                }
            } catch let error as NSError {
                print("Failed : \(error.localizedDescription)")
            }
          
            contentHandler(bestAttemptContent)
        }
    }
    
    override func serviceExtensionTimeWillExpire() {

        if let contentHandler = contentHandler, let bestAttemptContent =  bestAttemptContent {
            
            bestAttemptContent.title = ""
            bestAttemptContent.body = "Nextcloud notification"
            
            contentHandler(bestAttemptContent)
        }
    }

}