Add initial support for per feed notifications

Shared/UserNotifications/UserNotificationManager.swift

@@ -0,0 +1,48 @@
+//
+//  NotificationManager.swift
+//  NetNewsWire
+//
+//  Created by Maurice Parker on 10/2/19.
+//  Copyright © 2019 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import Account
+import Articles
+import UserNotifications
+
+final class UserNotificationManager: NSObject {
+	
+	override init() {
+		super.init()
+		NotificationCenter.default.addObserver(self, selector: #selector(accountDidDownloadArticles(_:)), name: .AccountDidDownloadArticles, object: nil)
+	}
+	
+	@objc func accountDidDownloadArticles(_ note: Notification) {
+		guard let articles = note.userInfo?[Account.UserInfoKey.newArticles] as? Set<Article> else {
+			return
+		}
+		
+		for article in articles {
+			if let feed = article.feed, feed.isNotifyAboutNewArticles ?? false {
+				sendNotification(feed: feed, article: article)
+			}
+		}
+	}
+
+}
+
+private extension UserNotificationManager {
+	
+	private func sendNotification(feed: Feed, article: Article) {
+		let content = UNMutableNotificationContent()
+		
+		content.title = feed.nameForDisplay
+		content.body = article.title ?? article.summary ?? ""
+		content.sound = UNNotificationSound.default
+		
+		let request = UNNotificationRequest.init(identifier: "articleID:\(article.articleID)", content: content, trigger: nil)
+		UNUserNotificationCenter.current().add(request)
+	}
+	
+}