import { MimcSponge, buildMimcSponge } from 'circomlibjs';
import type { Element, HashFunction } from '@tornado/fixed-merkle-tree';

export class Mimc {
  sponge?: MimcSponge;
  hash?: HashFunction<Element>;
  mimcPromise: Promise<void>;

  constructor() {
    this.mimcPromise = this.initMimc();
  }

  async initMimc() {
    this.sponge = await buildMimcSponge();
    this.hash = (left, right) => this.sponge?.F.toString(this.sponge?.multiHash([BigInt(left), BigInt(right)]));
  }

  async getHash() {
    await this.mimcPromise;

    return {
      sponge: this.sponge,
      hash: this.hash,
    };
  }
}

export const mimc = new Mimc();