actions.js

const { WsProvider, ApiPromise } = require('@polkadot/api')
const pdKeyring = require('@polkadot/keyring')
const fs = require('fs')

const SUBSTRATE_ENDPOINT =
  process.env.SUBSTRATE_ENDPOINT || 'wss://rpc-newrome.setheum.xyz/'
const DECIMALS = parseInt(process.env.DECIMALS) || 18
const TYPEDEFS_JSON = process.env.TYPEDEFS || ''

function loadJson(path) {
  const data = fs.readFileSync(path, { encoding: 'utf-8' })
  return JSON.parse(data)
}

class Actions {
  async create(
    mnemonic,
    url = SUBSTRATE_ENDPOINT,
    typedefPath = TYPEDEFS_JSON
  ) {
    const provider = new WsProvider(url)
    const types = typedefPath ? loadJson(typedefPath) : undefined
    this.api = await ApiPromise.create({ provider, types })
    const keyring = new pdKeyring.Keyring({ type: 'sr25519' })
    this.account = keyring.addFromMnemonic(mnemonic)
  }

  async sendDOTs(address, amount = 150) {
    amount = amount * 10 ** DECIMALS

    const transfer = this.api.tx.balances.transfer(address, amount)
    const hash = await transfer.signAndSend(this.account)

    return hash.toHex()
  }

  async checkBalance() {
    if (this.api.query.balances.freeBalance) {
      return this.api.query.balances.freeBalance(this.account.address)
    } else {
      const accountInfo = await this.api.query.system.account(
        this.account.address
      )
      return accountInfo.data.free
    }
  }
}

module.exports = Actions