NetNewsWire/Evergreen/SmartFeeds/SmartFeed.swift

103 lines
2.0 KiB
Swift

//
// SmartFeed.swift
// Evergreen
//
// Created by Brent Simmons on 11/19/17.
// Copyright © 2017 Ranchero Software. All rights reserved.
//
import Foundation
import RSCore
import Data
import Account
protocol SmartFeedDelegate: DisplayNameProvider {
func fetchUnreadCount(for: Account, callback: @escaping (Int) -> Void)
}
final class SmartFeed: PseudoFeed {
var nameForDisplay: String {
get {
return delegate.nameForDisplay
}
}
var unreadCount = 0 {
didSet {
if unreadCount != oldValue {
postUnreadCountDidChangeNotification()
}
}
}
private let delegate: SmartFeedDelegate
private var timer: Timer?
private var unreadCounts = [Account: Int]()
init(delegate: SmartFeedDelegate) {
self.delegate = delegate
NotificationCenter.default.addObserver(self, selector: #selector(unreadCountDidChange(_:)), name: .UnreadCountDidChange, object: nil)
startTimer() // Fetch unread count at startup
}
@objc func unreadCountDidChange(_ note: Notification) {
if note.object is Account {
startTimer()
}
}
}
private extension SmartFeed {
// MARK: - Unread Counts
private func fetchUnreadCount(for account: Account) {
delegate.fetchUnreadCount(for: account) { (accountUnreadCount) in
self.unreadCounts[account] = accountUnreadCount
self.updateUnreadCount()
}
}
private func fetchUnreadCounts() {
AccountManager.shared.accounts.forEach { self.fetchUnreadCount(for: $0) }
}
private func updateUnreadCount() {
unreadCount = AccountManager.shared.accounts.reduce(0) { (result, account) -> Int in
if let oneUnreadCount = unreadCounts[account] {
return result + oneUnreadCount
}
return result
}
}
// MARK: - Timer
func stopTimer() {
if let timer = timer {
timer.rs_invalidateIfValid()
}
timer = nil
}
private static let fetchCoalescingDelay: TimeInterval = 0.1
func startTimer() {
stopTimer()
timer = Timer.scheduledTimer(withTimeInterval: SmartFeed.fetchCoalescingDelay, repeats: false, block: { (timer) in
self.fetchUnreadCounts()
self.stopTimer()
})
}
}