export default class Snowflake {
  static current_increment = 0n;

  public static increment() {
    this.current_increment = BigInt.asUintN(12, this.current_increment + 1n);
    return this.current_increment;
  }

  state = 0n;
  public set_timestamp(value: number | bigint) {
    value = BigInt.asUintN(64 - 22, BigInt(value));
    const state = BigInt.asUintN(22, this.state);
    this.state = state + (value << 22n);
  }

  public set_machineid(value: number | bigint) {
    value = BigInt.asUintN(12 - 17, BigInt(value));
    const state = BigInt.asUintN(17, this.state) + (this.state >> 22n) << 22n;
    this.state = state + (value << 12n);
  }

  public set_processid(value: number | bigint) {
    value = BigInt.asUintN(17 - 12, BigInt(value));
    const state = BigInt.asUintN(12, this.state) + (this.state >> 17n) << 17n;
    this.state = state + (value << 12n);
  }

  public set_increment(value: number | bigint) {
    value = BigInt.asUintN(12 - 0, BigInt(value));
    const state = (this.state >> 12n) << 12n;
    this.state = state + (value << 0n);
  }

  constructor(value?: bigint) {
    if (value) {
      this.state = BigInt.asUintN(64, value);
      return;
    }
    this.set_timestamp(Date.now());
    this.set_processid(1);
    this.set_increment(Snowflake.increment());
  }

  public toString() {
    return this.state.toString();
  }

  public get timestamp() {
    return BigInt.asUintN(64 - 22, this.state >> 22n);
  }
}