fusebox_service.ts

import { FuseSDK } from '@fuseio/fusebox-web-sdk';
import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { Signer, Wallet, utils } from 'ethers';
import { ISendUserOperationResponse } from 'userop';

@Injectable()
export class FuseboxService {
  private fuseSDK: FuseSDK | null = null;

  constructor(private readonly configService: ConfigService) {}

  async ensureInitialized(): Promise<void> {
    if (!this.fuseSDK) {
      await this.init();
    }
  }

  private async init() {
    const publicKey = this.configService.getOrThrow('CHARGE_PUBLIC_API_KEY');
    const privateKey = this.configService.get('PRIVATE_KEY');

    const wallet = new Wallet(privateKey) as Signer;

    try {
      this.fuseSDK = await FuseSDK.init(publicKey, wallet);
      console.log('FuseSDK initialized successfully:', this.fuseSDK);
    } catch (error) {
      console.error('Error initializing FuseSDK:', error);
      throw new Error('Failed to initialize FuseSDK.');
    }
  }

  async transferNativeToken(
    recipientAddress: string,
    amount: number,
    options?: TxOptions,
  ): Promise<ISendUserOperationResponse> {
    await this.ensureInitialized();

    return this.fuseSDK.callContract(
      recipientAddress,
      utils.parseEther(amount.toString()),
      new Uint8Array(0),
      options,
    );
  }
}

interface TxOptions {
  feePerGas: string;
  feeIncrementPercentage: number;
  withRetry: boolean;
}