AccountsStakingInfoService.ts

// Copyright 2017-2022 Parity Technologies (UK) Ltd.
// This file is part of Substrate API Sidecar.
//
// Substrate API Sidecar 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 <http://www.gnu.org/licenses/>.

import { BlockHash } from '@polkadot/types/interfaces';
import { BadRequest, InternalServerError } from 'http-errors';
import { IAccountStakingInfo } from 'src/types/responses';

import { AbstractService } from '../AbstractService';

export class AccountsStakingInfoService extends AbstractService {
	/**
	 * Fetch staking information for a _Stash_ account at a given block.
	 *
	 * @param hash `BlockHash` to make call at
	 * @param stash address of the _Stash_  account to get the staking info of
	 */
	async fetchAccountStakingInfo(hash: BlockHash, stash: string): Promise<IAccountStakingInfo> {
		const { api } = this;
		const historicApi = await api.at(hash);

		const [header, controllerOption] = await Promise.all([
			api.rpc.chain.getHeader(hash),
			historicApi.query.staking.bonded(stash), // Option<AccountId> representing the controller
		]).catch((err: Error) => {
			throw this.createHttpErrorForAddr(stash, err);
		});

		const at = {
			hash,
			height: header.number.unwrap().toString(10),
		};

		if (controllerOption.isNone) {
			throw new BadRequest(`The address ${stash} is not a stash address.`);
		}

		const controller = controllerOption.unwrap();

		const [stakingLedgerOption, rewardDestination, slashingSpansOption] = await Promise.all([
			historicApi.query.staking.ledger(controller),
			historicApi.query.staking.payee(stash),
			historicApi.query.staking.slashingSpans(stash),
		]).catch((err: Error) => {
			throw this.createHttpErrorForAddr(stash, err);
		});

		const stakingLedger = stakingLedgerOption.unwrapOr(null);

		if (stakingLedger === null) {
			// should never throw because by time we get here we know we have a bonded pair
			throw new InternalServerError(
				`Staking ledger could not be found for controller address "${controller.toString()}"`,
			);
		}

		const numSlashingSpans = slashingSpansOption.isSome ? slashingSpansOption.unwrap().prior.length + 1 : 0;

		return {
			at,
			controller,
			rewardDestination,
			numSlashingSpans,
			staking: stakingLedger,
		};
	}
}