//

// CacheManager.swift

// iina

//

// Created by lhc on 28/9/2017.

// Copyright © 2017 lhc. All rights reserved.

//

import Cocoa

class CacheManager {

static var shared = CacheManager()

var isJobRunning = false

var needsRefresh = true

private var cachedContents: [URL]?

private func cacheFolderContents() -> [URL]? {

if needsRefresh {

cachedContents = try? FileManager.default.contentsOfDirectory(at: Utility.thumbnailCacheURL,

includingPropertiesForKeys: [.fileSizeKey, .contentAccessDateKey],

options: [.skipsHiddenFiles, .skipsSubdirectoryDescendants])

}

return cachedContents

}

func getCacheSize() -> Int {

return cacheFolderContents()?.reduce(0 as Int) { totalSize, url in

let size = (try? url.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? 0

return totalSize + size

} ?? 0

}

func clearOldCache() {

guard !isJobRunning else { return }

isJobRunning = true

let maxCacheSize = Preference.integer(for: .maxThumbnailPreviewCacheSize)

// if full, delete 50% of max cache

let cacheToDelete = maxCacheSize * FloatingPointByteCountFormatter.PrefixFactor.mi.rawValue / 2

// sort by access date

guard let contents = cacheFolderContents()?.sorted(by: { url1, url2 in

let date1 = (try? url1.resourceValues(forKeys: [.contentAccessDateKey]).contentAccessDate) ?? Date.distantPast

let date2 = (try? url2.resourceValues(forKeys: [.contentAccessDateKey]).contentAccessDate) ?? Date.distantPast

return date1.compare(date2) == .orderedAscending

}) else { return }

// delete old cache

var clearedCacheSize = 0

for url in contents {

let size = (try? url.resourceValues(forKeys: [.fileSizeKey]))?.fileSize ?? 0

if clearedCacheSize < cacheToDelete {

try? FileManager.default.removeItem(at: url)

clearedCacheSize += size

} else {

break

}

}

}

}