import { BlockHash, StorageData, StorageKey } from '@dedot/codecs';
import type { Callback, Unsub } from '@dedot/types';
import { ISubstrateClient, ISubstrateClientAt } from '../types.js';
/**
 * @name BaseStorageQuery
 * @description
 * An abstract service that provides functionality for querying and subscribing to
 * multiple storage items. This service is designed to be extended by version-specific
 * implementations that handle the details of interacting with different JSON-RPC APIs.
 *
 * The service provides a simple interface for:
 * - Querying multiple storage keys in a single call
 * - Subscribing to changes in multiple storage keys
 *
 * This abstraction eliminates code duplication between different client implementations
 * and provides a consistent interface for storage operations.
 */
export declare abstract class BaseStorageQuery {
    protected client: ISubstrateClientAt<any> | ISubstrateClient<any, any>;
    /**
     * @param client - The substrate client instance
     */
    protected constructor(client: ISubstrateClientAt<any> | ISubstrateClient<any, any>);
    /**
     * Query multiple storage items in a single call
     *
     * @param keys - Array of storage keys to query
     * @param at - Optional block hash to query at
     * @returns Promise resolving to a record mapping storage keys to their values
     */
    abstract query(keys: StorageKey[], at?: BlockHash): Promise<Record<StorageKey, StorageData | undefined>>;
    /**
     * Subscribe to multiple storage items
     *
     * @param keys - Array of storage keys to subscribe to
     * @param callback - Function to call when storage values change
     * @returns Promise resolving to an unsubscribe function
     */
    abstract subscribe(keys: StorageKey[], callback: Callback<Record<StorageKey, StorageData | undefined>>): Promise<Unsub>;
}