import Foundation

class FileDownloader: NSObject, URLSessionDownloadDelegate {
    private var completion: ((URL?, Error?) -> Void)?
    
    func downloadFile(from url: URL, completion: @escaping (URL?, Error?) -> Void) {
        self.completion = completion
        let session = URLSession(configuration: .default, delegate: self, delegateQueue: nil)
        let task = session.downloadTask(with: url)
        task.resume()
    }
    
    // MARK: - URLSessionDownloadDelegate
    
    func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
        let destinationURL = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
        do {
            try FileManager.default.moveItem(at: location, to: destinationURL)
            DispatchQueue.main.async {
                self.completion?(destinationURL, nil)
            }
        } catch {
            DispatchQueue.main.async {
                self.completion?(nil, error)
            }
        }
    }
    
    func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
        if let error = error {
            DispatchQueue.main.async {
                self.completion?(nil, error)
            }
        }
    }
}