import type { Amount } from './Amount';
/**
 * A UTXO that is tracked locally (either as spent or as a new unspent change output).
 */
export interface CachedUtxo {
    txid: string;
    n: number;
    amount: Amount;
    script: Uint8Array;
}
/**
 * Local cache that tracks spent and unspent UTXOs between broadcast and API indexing.
 *
 * When a transaction is broadcast, the API may still return the spent inputs
 * (stale) and may not yet know about the new change outputs. This cache bridges
 * that gap so that successive transactions can be built immediately.
 *
 * - **Spent**: UTXOs consumed by a local broadcast. Filtered out even if the
 *   API still returns them.
 * - **Unspent**: Change outputs created by a local broadcast. Included even if
 *   the API does not know about them yet.
 *
 * When a broadcasted transaction is confirmed, {@link confirmTransaction} should
 * be called to clean up the cache entries (the API has caught up).
 */
export declare class UtxoLocalCache {
    /** "txid:n" → broadcastTxId that consumed the UTXO. */
    private spent;
    /** address → locally created unspent UTXOs. */
    private unspent;
    /**
     * Marks a UTXO as spent by a broadcast transaction.
     *
     * If the UTXO was a locally cached unspent (e.g. a change output from a
     * previous broadcast), it is also removed from the unspent set.
     */
    markSpent(txid: string, n: number, broadcastTxId: string): void;
    /** Returns `true` if the UTXO has been marked as spent by a local broadcast. */
    isSpent(txid: string, n: number): boolean;
    /** Adds a new unspent UTXO (typically a change output from a local broadcast). */
    addUnspent(address: string, utxo: CachedUtxo): void;
    /** Returns a copy of locally cached unspent UTXOs for the given address. */
    getUnspent(address: string): CachedUtxo[];
    /**
     * Cleans up cache entries for a confirmed broadcast transaction.
     *
     * Once the API has indexed the transaction, the local overrides are no longer
     * needed:
     * - Spent entries consumed by this broadcast are removed.
     * - Unspent entries created by this broadcast are removed.
     */
    confirmTransaction(broadcastTxId: string): void;
}