在swift 5中将短URL转换为完整url

import Foundation

func expandShortURL(shortURL: String, completion: @escaping (URL?) -> Void) {
    guard let url = URL(string: shortURL) else {
        completion(nil)
        return
    }
    
    let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
        guard let data = data,
              let longURLString = String(data: data, encoding: .utf8),
              let longURL = URL(string: longURLString) else {
            completion(nil)
            return
        }
        
        completion(longURL)
    }
    
    task.resume()
}

// 使用示例
let shortURL = "https://t.cn/ABC123"
expandShortURL(shortURL: shortURL) { (longURL) in
    if let longURL = longURL {
        print("完整URL: \(longURL)")
    } else {
        print("无法获取完整URL")
    }
}