import { type CachedTable } from "@snort/shared";
import type { RequestBuilder, SystemInterface, TaggedNostrEvent } from ".";
/** Debounce intervals (ms) per priority tier */
declare const FlushIntervals: {
    readonly high: 50;
    readonly normal: 500;
    readonly low: 5000;
};
export type ProfilePriority = keyof typeof FlushIntervals;
export declare abstract class BackgroundLoader<T extends {
    loaded: number;
    created: number;
}> {
    #private;
    readonly cache: CachedTable<T>;
    /**
     * Custom loader function for fetching data from alternative sources
     */
    loaderFn?: (pubkeys: Array<string>) => Promise<Array<T>>;
    constructor(system: SystemInterface, cache: CachedTable<T>);
    /**
     * Stop all pending flush timers.
     * Call this when the loader is no longer needed to prevent timer leaks.
     */
    destroy(): void;
    /**
     * Name of this loader service
     */
    abstract name(): string;
    /**
     * Handle fetched data
     */
    abstract onEvent(e: Readonly<TaggedNostrEvent>): T | undefined;
    /**
     * Get expire time as unix milliseconds
     */
    abstract getExpireCutoff(): number;
    /**
     * Build subscription for a chunk of missing keys
     */
    protected abstract buildSub(missing: Array<string>): RequestBuilder;
    /**
     * Start requesting a set of keys to be loaded.
     * @param pk One or more hex pubkeys
     * @param priority Priority tier — higher tiers flush sooner (default: "normal")
     */
    TrackKeys(pk: string | Array<string>, priority?: ProfilePriority): void;
    /**
     * Stop requesting a set of keys to be loaded
     */
    UntrackKeys(pk: string | Array<string>): void;
    /**
     * Get object from cache or fetch if missing
     */
    fetch(key: string, timeoutMs?: number): Promise<T>;
}
export {};
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