joystream/storage-node/packages/runtime-api/balances.js

/*
 * This file is part of the storage node for the Joystream project.
 * Copyright (C) 2019 Joystream Contributors
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

'use strict'

const debug = require('debug')('joystream:runtime:balances')

const { IdentitiesApi } = require('@joystream/storage-runtime-api/identities')

/*
 * Bundle API calls related to account balances.
 */
class BalancesApi {
	static async create(base) {
		const ret = new BalancesApi()
		ret.base = base
		await ret.init()
		return ret
	}

	async init(account_file) {
		debug('Init')
	}

	/*
	 * Return true/false if the account has the minimum balance given.
	 */
	async hasMinimumBalanceOf(accountId, min) {
		const balance = await this.freeBalance(accountId)
		if (typeof min === 'number') {
			return balance.cmpn(min) >= 0
		}
		return balance.cmp(min) >= 0
	}

	/*
	 * Return the account's current free balance.
	 */
	async freeBalance(accountId) {
		const decoded = this.base.identities.keyring.decodeAddress(accountId, true)
		return this.base.api.query.balances.freeBalance(decoded)
	}

	/*
	 * Return the base transaction fee.
	 */
	baseTransactionFee() {
		return this.base.api.consts.transactionPayment.transactionBaseFee
	}

	/*
	 * Transfer amount currency from one address to another. The sending
	 * address must be an unlocked key pair!
	 */
	async transfer(from, to, amount) {
		const decode = require('@polkadot/keyring').decodeAddress
		const to_decoded = decode(to, true)

		const tx = this.base.api.tx.balances.transfer(to_decoded, amount)
		return this.base.signAndSend(from, tx)
	}
}

module.exports = {
	BalancesApi,
}