NetNewsWire/Shared/Extensions/CacheCleaner.swift

//
//  CacheCleaner.swift
//  NetNewsWire
//
//  Created by Maurice Parker on 11/8/19.
//  Copyright © 2019 Ranchero Software. All rights reserved.
//

import Foundation
import os.log
import Web

struct CacheCleaner {

	nonisolated(unsafe) static let log = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "CacheCleaner")

	@MainActor static func purgeIfNecessary() {

		guard let flushDate = AppDefaults.shared.lastImageCacheFlushDate else {
			AppDefaults.shared.lastImageCacheFlushDate = Date()
			return
		}

		// If the image disk cache hasn't been flushed for 3 days and the network is available, delete it
		if flushDate.addingTimeInterval(3600 * 24 * 3) < Date() {
			if Reachability.internetIsReachable {

				let tempDir = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first!
				let faviconsFolderURL = tempDir.appendingPathComponent("Favicons")
				let imagesFolderURL = tempDir.appendingPathComponent("Images")
				let feedURLToIconURL = tempDir.appendingPathComponent("FeedURLToIconURLCache.plist")
				let homePageToIconURL = tempDir.appendingPathComponent("HomePageToIconURLCache.plist")
				let homePagesWithNoIconURL = tempDir.appendingPathComponent("HomePagesWithNoIconURLCache.plist")

				for tempItem in [faviconsFolderURL, imagesFolderURL, feedURLToIconURL, homePageToIconURL, homePagesWithNoIconURL] {
					do {
						os_log(.info, log: self.log, "Removing cache file: %@", tempItem.absoluteString)
						try FileManager.default.removeItem(at: tempItem)
					} catch {
						os_log(.error, log: self.log, "Could not delete cache file: %@", error.localizedDescription)
					}
				}

				AppDefaults.shared.lastImageCacheFlushDate = Date()
			}
		}
	}
}