cic-staff-client/src/app/_eth/accountIndex.ts

// @ts-ignore
import * as accountIndex from '@src/assets/js/block-sync/data/AccountRegistry.json';
import {environment} from '@src/environments/environment';
const Web3 = require('web3');

const web3 = new Web3(environment.web3Provider);
const abi = accountIndex.default;

export class AccountIndex {
  contractAddress: string;
  signerAddress: string;
  contract: any;

  constructor(contractAddress: string, signerAddress?: string) {
    this.contractAddress = contractAddress;
    this.contract = new web3.eth.Contract(abi, this.contractAddress);
    if (signerAddress) {
      this.signerAddress = signerAddress;
    } else {
      this.signerAddress = web3.eth.accounts[0];
    }
  }

  public async totalAccounts(): Promise<number> {
    return await this.contract.methods.count().call();
  }

  public async haveAccount(address: string): Promise<boolean> {
    return await this.contract.methods.accountIndex(address).call() !== 0;
  }

  public async last(numberOfAccounts: number): Promise<Array<string>> {
    const count = await this.totalAccounts();
    let lowest = count - numberOfAccounts - 1;
    if (lowest < 0) {
      lowest = 0;
    }
    let accounts = [];
    for (let i = count - 1; i > lowest; i--) {
      const account = await this.contract.methods.accounts(i).call();
      accounts.push(account);
    }
    return accounts;
  }

  public async addToAccountRegistry(address: string): Promise<boolean> {
    if (!await this.haveAccount(address)) {
      return await this.contract.methods.add(address).send({from: this.signerAddress});
    } else {
      return await this.haveAccount(address);
    }
  }
}