using Yitter.IdGenerator;

namespace Easy.Snowflakes;
public class DriftingSnowflakeIdGenerator 
{
    private static bool _isSet = false;
    public static byte WorkerIdBitLength => 6;
    public static byte SeqBitLength => 6;
    public static short MaxWorkerId => (short)(Math.Pow(2.0, WorkerIdBitLength) - 1);
    public static short CurrentWorkerId { get; private set; } = -1;
    private static readonly object _locker = new();

    /// <summary>
    /// 生成新的Id
    /// </summary>
    /// <returns></returns>
    public static long Create()
    {
        if (!_isSet)
            throw new InvalidOperationException("please call SetIdGenerator first");

        return YitIdHelper.NextId();
    }

    /// <summary>
    /// 初始化Id生成器
    /// </summary>
    /// <param name="workerId"></param>
    public static void SetWorkerId(ushort workerId)
    {
        if (_isSet)
            throw new InvalidOperationException("allow only once");

        if (workerId > MaxWorkerId || workerId < 0)
            throw new ArgumentException($"worker Id can't be greater than {MaxWorkerId} or less than 0");

        lock (_locker)
        {
            if (_isSet)
                throw new InvalidOperationException("allow only once");

            YitIdHelper.SetIdGenerator(new IdGeneratorOptions(workerId)
            {
                WorkerIdBitLength = WorkerIdBitLength,
                SeqBitLength = SeqBitLength,
                BaseTime = DateTime.Parse("2022-01-01 00:00:00")
            });

            CurrentWorkerId = (short)workerId;
            _isSet = true;
        }

    }

}