import UIKit

class CacheTool: NSObject {

    /// 計算緩存大小
    static var cacheSize: String{
        get{
            // 路徑
            let basePath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.cachesDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).first
            let fileManager = FileManager.default
            // 遍歷出所有緩存文件加起來的大小
            func caculateCache() -> Float{
                var total: Float = 0
                if fileManager.fileExists(atPath: basePath!){
                    let childrenPath = fileManager.subpaths(atPath: basePath!)
                    if childrenPath != nil{
                        for path in childrenPath!{
                            let childPath = basePath!.appending("/").appending(path)
                            do{
                                let attr:NSDictionary = try fileManager.attributesOfItem(atPath: childPath) as NSDictionary
                                let fileSize = attr["NSFileSize"] as! Float
                                total += fileSize
                                
                            }catch _{
                                
                            }
                        }
                    }
                }
                // 緩存文件大小
                return total
            }
            // 調用函數
            let totalCache = caculateCache()
            return NSString(format: "%.2f MB", totalCache / 1024.0 / 1024.0 ) as String
        }
    }
    
    /// 清除緩存
    ///
    /// - returns: 是否清理成功
    class func clearCache() -> Bool {
        var result = true
        // 取出cache文件夾目錄 緩存文件都在這個目錄下
        let cachePath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.cachesDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).first
        // 取出文件夾下所有文件數組
        let fileArr = FileManager.default.subpaths(atPath: cachePath!)
        // 遍歷刪除
        for file in fileArr! {
            // 拼接文件路徑
            let path = cachePath?.appending("/\(file)")
            if FileManager.default.fileExists(atPath: path!) {
                // 循環(huán)刪除
                do {
                    try FileManager.default.removeItem(atPath: path!)
                } catch {
                    // 刪除失敗
                    result = false
                }
            }
        }
        return result
    }
}