using Dolphin.ExamPictureCut.Constants;
using System.Timers;
using Yitter.IdGenerator;
using Timer = System.Timers.Timer;

namespace Dolphin.ExamPictureCut.Extensions;

public class IdExt
{
    public static IdGeneratorOptions GetIdGeneratorOptions(string uniqueValue)
    {
        byte workerIdBitLength = 8;
        var maxWorkId = Math.Pow(2, workerIdBitLength) - 1; //63
        var workIdKey = $"{uniqueValue}idgen:workid";

        var workId = GetNextWorkId();

        while (!RedisHelper.SetNx($"{workIdKey}:{workId}", SysConsts.AppName))
        {
            // workId 已被占用，获取下一个workId
            workId = GetNextWorkId();
        };

        // 设置5分钟过期
        RedisHelper.Expire($"{workIdKey}:{workId}", 60 * 5);

        // 设置定时器，每4分钟更新一次过期时间
        SetTimer(4, (s, e) =>
        {
            RedisHelper.Expire($"{workIdKey}:{workId}", 60 * 5);
        });

        // WorkerIdBitLength + SeqBitLength 不超过 22 
        return new IdGeneratorOptions
        {
            WorkerIdBitLength = workerIdBitLength,
            //SeqBitLength = 6,  // 数值越高，性能越好，但是Id也越长
            WorkerId = (ushort)workId
        };

        long GetNextWorkId()
        {
            var workId = RedisHelper.IncrBy(workIdKey);
            if (workId > maxWorkId)
            {
                // 大于了最大可用WorkId,重置workId，并获取
                RedisHelper.Set(workIdKey, -1);
                workId = RedisHelper.IncrBy(workIdKey);
            }

            return workId;
        }
    }

    private static Timer _timer;
    private static void SetTimer(int mins, ElapsedEventHandler eh)
    {
        // 创建一个 Timer 实例，并设置其相关属性
        _timer = new Timer(TimeSpan.FromMinutes(mins).TotalMilliseconds); // 4 分钟
        _timer.Elapsed += eh;
        _timer.AutoReset = true; // 设置 Timer 实例能否多次触发
        _timer.Enabled = true; // 启动 Timer 实例
    }
}