packages/react-hooks/src/useAvailableSlashes.ts
// Copyright 2017-2024 @polkadot/react-hooks authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { DeriveSessionIndexes } from '@polkadot/api-derive/types';
import type { Option } from '@polkadot/types';
import type { EraIndex } from '@polkadot/types/interfaces';
import type { PalletStakingUnappliedSlash } from '@polkadot/types/lookup';
import { useEffect, useState } from 'react';
import { BN, BN_HUNDRED, BN_ONE, BN_ZERO } from '@polkadot/util';
import { createNamedHook } from './createNamedHook.js';
import { useApi } from './useApi.js';
import { useCall } from './useCall.js';
import { useIsMountedRef } from './useIsMountedRef.js';
type Unsub = () => void;
function useAvailableSlashesImpl (): [BN, PalletStakingUnappliedSlash[]][] {
const { api } = useApi();
const indexes = useCall<DeriveSessionIndexes>(api.derive.session?.indexes);
const earliestSlash = useCall<Option<EraIndex>>(api.query.staking?.earliestUnappliedSlash);
const mountedRef = useIsMountedRef();
const [slashes, setSlashes] = useState<[BN, PalletStakingUnappliedSlash[]][]>([]);
useEffect((): Unsub => {
let unsub: Unsub | undefined;
const [from, offset] = api.query.staking?.earliestUnappliedSlash
? [earliestSlash?.unwrapOr(null), BN_ZERO]
// future depth (one more than activeEra for delay)
: [indexes?.activeEra, BN_ONE.add(api.consts.staking?.slashDeferDuration || BN_HUNDRED)];
if (mountedRef.current && indexes && from) {
const range: BN[] = [];
const end = indexes.activeEra.add(offset);
let start = new BN(from);
while (start.lte(end)) {
range.push(start);
start = start.add(BN_ONE);
}
if (range.length) {
(async (): Promise<void> => {
unsub = await api.query.staking.unappliedSlashes.multi(range, (values): void => {
mountedRef.current && setSlashes(
values
.map((value, index): [BN, PalletStakingUnappliedSlash[]] => [from.addn(index), value])
.filter(([, slashes]) => slashes.length)
);
});
})().catch(console.error);
}
}
return (): void => {
unsub && unsub();
};
}, [api, earliestSlash, indexes, mountedRef]);
return slashes;
}
export const useAvailableSlashes = createNamedHook('useAvailableSlashes', useAvailableSlashesImpl);