// Copyright 2017-2020 @polkadot/react-components authors & contributors
// This software may be modified and distributed under the terms
// of the Apache-2.0 license. See the LICENSE file for details.

import { DeriveStakingAccount } from '@polkadot/api-derive/types';
import { SlashingSpans } from '@polkadot/types/interfaces';

import React from 'react';
import { useAccounts, useApi, useCall } from '@polkadot/react-hooks';
import { FormatBalance } from '@polkadot/react-query';
import { Option } from '@polkadot/types';

import TxButton from './TxButton';
import { useTranslation } from './translate';

interface Props {
  className?: string;
  stakingInfo?: DeriveStakingAccount;
}

const transformSpan = {
  transform: (optSpans: Option<SlashingSpans>): number =>
    optSpans.isNone
      ? 0
      : optSpans.unwrap().prior.length + 1
};

function StakingRedeemable ({ className = '', stakingInfo }: Props): React.ReactElement<Props> | null {
  const { api } = useApi();
  const { allAccounts } = useAccounts();
  const { t } = useTranslation();
  const spanCount = useCall<number>(api.query.staking.slashingSpans, [stakingInfo?.stashId], transformSpan);

  if (!stakingInfo?.redeemable?.gtn(0)) {
    return null;
  }

  return (
    <div className={className}>
      <FormatBalance value={stakingInfo.redeemable}>
        {allAccounts.includes((stakingInfo.controllerId || '').toString()) && (
          <TxButton
            accountId={stakingInfo.controllerId}
            icon='lock'
            isIcon
            key='unlock'
            params={
              api.tx.staking.withdrawUnbonded.meta.args.length === 1
                ? [spanCount]
                : []
            }
            tooltip={t<string>('Withdraw these unbonded funds')}
            tx='staking.withdrawUnbonded'
          />
        )}
      </FormatBalance>
    </div>
  );
}

export default React.memo(StakingRedeemable);