using System;
using UnityEngine.Networking;
using System.Threading.Tasks;
using Fort23.UTool;

namespace Fort23.Core
{
    public static class NetworkTime
    {
        // 百度服务器时间（通过 HTTP Date 头）
        private static readonly string BaiduUrl = "https://www.baidu.com";

        public static async Task<DateTime?> GetNetworkTimeAsync()
        {
            try
            {
                using var www = UnityWebRequest.Head(BaiduUrl); 
                www.timeout = 5;

                var operation = www.SendWebRequest();
                while (!operation.isDone)
                    await Task.Yield();

                if (www.result == UnityWebRequest.Result.Success)
                {
                    string dateHeader = www.GetResponseHeader("Date");
                    if (!string.IsNullOrEmpty(dateHeader))
                    {
                        // 解析 RFC 1123 格式的时间字符串
                        if (DateTime.TryParse(dateHeader, null, System.Globalization.DateTimeStyles.AssumeUniversal, out DateTime serverTime))
                        {
                            var utcTime = serverTime.ToUniversalTime();
                            LogTool.Log($"百度服务器时间: {utcTime:yyyy-MM-dd HH:mm:ss} UTC");
                            return utcTime;
                        }
                    }
                }
                else
                {
                    LogTool.Error($"请求百度失败: {www.error}");
                }
            }
            catch (Exception e)
            {
                LogTool.Error($"[NetworkTime]异常: {e.Message}");
            }

            LogTool.Error("[NetworkTime]获取百度时间失败");
            return null;
        }
    }
}