using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MvvmScaffoldFrame48.DLL.SystemTools
{
    public static class TimeStampTools
    {
        public static DateTime FromUnixTimestamp(long timestamp, bool isMilliseconds = false)
        {
            try
            {
                // 如果未指定单位，尝试自动检测
                if (!isMilliseconds)
                {
                    // 如果时间戳看起来像毫秒级（13位数字）
                    if (timestamp.ToString().Length > 10)
                    {
                        isMilliseconds = true;
                    }
                }

                if (isMilliseconds)
                {
                    // 验证毫秒级时间戳范围
                    const long minMilliTimestamp = -62135596800000; // 0001-01-01 00:00:00 UTC
                    const long maxMilliTimestamp = 253402300799999; // 9999-12-31 23:59:59 UTC

                    if (timestamp < minMilliTimestamp || timestamp > maxMilliTimestamp)
                    {
                        throw new ArgumentOutOfRangeException(nameof(timestamp),
                            "毫秒级时间戳超出有效范围");
                    }

                    DateTime origin = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).AddMilliseconds(timestamp);
                    return TimeZoneInfo.ConvertTimeFromUtc(origin, TimeZoneInfo.Local);
                }
                else
                {
                    // 验证秒级时间戳范围
                    const long minTimestamp = -62135596800;
                    const long maxTimestamp = 253402300799;

                    if (timestamp < minTimestamp || timestamp > maxTimestamp)
                    {
                        throw new ArgumentOutOfRangeException(nameof(timestamp),
                            "秒级时间戳超出有效范围");
                    }

                    DateTime origin = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).AddSeconds(timestamp);
                    return TimeZoneInfo.ConvertTimeFromUtc(origin, TimeZoneInfo.Local);
                }
            }
            catch (ArgumentOutOfRangeException)
            {
                throw;
            }
            catch (Exception ex)
            {
                throw new ArgumentException($"无法转换时间戳 {timestamp}: {ex.Message}", ex);
            }
        }
    }
}