import { AbstractPowerSyncDatabase } from '../../../client/AbstractPowerSyncDatabase.js';
import { MetaBaseObserver } from '../../../utils/MetaBaseObserver.js';
import { WatchedQuery, WatchedQueryListener, WatchedQueryOptions, WatchedQueryState } from '../WatchedQuery.js';
/**
 * @internal
 */
export interface AbstractQueryProcessorOptions<Data, Settings extends WatchedQueryOptions = WatchedQueryOptions> {
    db: AbstractPowerSyncDatabase;
    watchOptions: Settings;
    placeholderData: Data;
}
/**
 * @internal
 */
export interface LinkQueryOptions<Data, Settings extends WatchedQueryOptions = WatchedQueryOptions> {
    abortSignal: AbortSignal;
    settings: Settings;
}
type MutableDeep<T> = T extends ReadonlyArray<infer U> ? U[] : T;
/**
 * @internal Mutable version of {@link WatchedQueryState}.
 * This is used internally to allow updates to the state.
 */
export type MutableWatchedQueryState<Data> = {
    -readonly [P in keyof WatchedQueryState<Data>]: MutableDeep<WatchedQueryState<Data>[P]>;
};
type WatchedQueryProcessorListener<Data> = WatchedQueryListener<Data>;
/**
 * Performs underlying watching and yields a stream of results.
 * @internal
 */
export declare abstract class AbstractQueryProcessor<Data = unknown[], Settings extends WatchedQueryOptions = WatchedQueryOptions> extends MetaBaseObserver<WatchedQueryProcessorListener<Data>> implements WatchedQuery<Data, Settings> {
    protected options: AbstractQueryProcessorOptions<Data, Settings>;
    readonly state: WatchedQueryState<Data>;
    protected abortController: AbortController;
    protected initialized: Promise<void>;
    protected _closed: boolean;
    protected disposeListeners: (() => void) | null;
    get closed(): boolean;
    constructor(options: AbstractQueryProcessorOptions<Data, Settings>);
    protected constructInitialState(): WatchedQueryState<Data>;
    protected get reportFetching(): boolean;
    protected updateSettingsInternal(settings: Settings, signal: AbortSignal): Promise<void>;
    /**
     * Updates the underlying query.
     */
    updateSettings(settings: Settings): Promise<void>;
    /**
     * This method is used to link a query to the subscribers of this listener class.
     * This method should perform actual query watching and report results via {@link updateState} method.
     */
    protected abstract linkQuery(options: LinkQueryOptions<Data>): Promise<void>;
    protected updateState(update: Partial<MutableWatchedQueryState<Data>>): Promise<void>;
    /**
     * Configures base DB listeners and links the query to listeners.
     */
    protected init(signal: AbortSignal): Promise<void>;
    close(): Promise<void>;
    /**
     * Runs a callback and reports errors to the error listeners.
     */
    protected runWithReporting<T>(callback: () => Promise<T>): Promise<void>;
    /**
     * Iterate listeners and reports errors to onError handlers.
     */
    protected iterateAsyncListenersWithError(callback: (listener: Partial<WatchedQueryProcessorListener<Data>>) => Promise<void> | void): Promise<void>;
}
export {};