using System;
using System.Globalization;

namespace GFGGame
{
    public class LauncherTimeUtil
    {
        private static DateTime dt = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

        private static readonly string[] Formats =
        {
            "HH:mm",
            "'['yyyy']['M']['dd']'",
            "'['yyyy']['MM']['d']'",
            "'['yyyy']['M']['d']'",
            "'['yyyy']['MM']['dd']'",
            "'['yyyy']['MM']['dd']['HH:mm']'",
            "'['yyyy']['MM']['dd']['H:mm']'",
            "'['yyyy']['M']['dd']['HH:mm']'",
            "'['yyyy']['M']['dd']['H:mm']'",
            "'['yyyy']['MM']['d']['HH:mm']'",
            "'['yyyy']['MM']['d']['H:mm']'",
            "'['yyyy']['M']['d']['HH:mm']'",
            "'['yyyy']['M']['d']['H:mm']'",
            "'['yyyy']['MM']['dd']['HH:mm:ss']'",
            "'['yyyy']['M']['dd']['HH:mm:ss']'",
            "'['yyyy']['MM']['d']['HH:mm:ss']'",
            "'['yyyy']['M']['d']['HH:mm:ss']'",
        };

        private static DateTime GetDateTime(string timeStr)
        {
            if (DateTime.TryParseExact(timeStr, Formats, null, DateTimeStyles.None, out var result))
            {
                return result;
            }

            throw new FormatException("Invalid date format");
        }

        //转换成时间戳，单位毫秒
        public static long GetTimestamp(string timeStr)
        {
            var dateTime = GetDateTime(timeStr);
            return Transition(dateTime);
        }

        // 获取当前时间的时间戳，单位毫秒
        public static long GetCurrentTimestamp()
        {
            DateTime now = DateTime.UtcNow;
            return Transition(now);
        }

        private static long Transition(DateTime d)
        {
            return (d.Ticks - dt.Ticks) / 10000;
        }
    }
}