/**
 * Node status client.
 *
 * `createNodeStatusClient(opts)` produces a small subscribe/current/stop client
 * that surfaces a {@link NodeStatusSetView} in one of two modes:
 *
 * - **remote**: connect to a node's `/ws/status` WebSocket feed, decode the
 *   size-prefixed `$NST` binary frames, and re-emit on every update.
 *   Auto-reconnects with capped exponential backoff + jitter.
 * - **helia**: given an SDN Helia node ({@link HeliaSDNNode} from
 *   `createHeliaSDNNode`), assemble the same view client-side from the local
 *   libp2p peer id, connection state to the two SDN bootstrap peers, EPM/vCard
 *   resolution, and opportunistic geo coordinates from any reachable remote
 *   `/ws/status` feed.
 *
 * Both modes are fail-open: transient errors never throw out of the client;
 * they are reported through `opts.onError` (when provided) and the client keeps
 * running.
 */
import type { HeliaSDNNode } from '../helia';
import { type NodeStatusSetView } from './view-model';
/** Minimal structural WebSocket used by the client (browser / `ws` / mocks). */
export interface WebSocketLike {
    binaryType: string;
    readonly readyState: number;
    send(data: string | ArrayBufferLike | ArrayBufferView): void;
    close(code?: number, reason?: string): void;
    onopen: ((event: unknown) => void) | null;
    onclose: ((event: unknown) => void) | null;
    onerror: ((event: unknown) => void) | null;
    onmessage: ((event: {
        data?: unknown;
    }) => void) | null;
}
/** Constructor shape for a {@link WebSocketLike}. */
export type WebSocketCtor = new (url: string) => WebSocketLike;
/** A subscriber for status set updates. */
export type NodeStatusListener = (view: NodeStatusSetView) => void;
/** The shared client interface exposed by both modes. */
export interface NodeStatusClient {
    /**
     * Subscribe to status updates. The current view (if any) is delivered
     * synchronously on subscribe. Returns an unsubscribe function.
     */
    subscribe(cb: NodeStatusListener): () => void;
    /** The most recently emitted view, or `null` before the first update. */
    current(): NodeStatusSetView | null;
    /** Stop the client, closing sockets/timers. Idempotent. */
    stop(): void;
}
/** Options for {@link createNodeStatusClient}. */
export interface NodeStatusClientOptions {
    /**
     * Remote mode: URL of the node's status feed. Accepts `wss://`, `ws://`,
     * `https://`, `http://`, or a bare host. When no explicit `/ws/...` path is
     * present, `/ws/status` is appended (https → wss, http → ws).
     */
    url?: string;
    /** Helia mode: an SDN Helia node from `createHeliaSDNNode`. */
    helia?: HeliaSDNNode;
    /** Helia mode: reassembly interval in ms (default 5000). */
    refreshIntervalMs?: number;
    /** Remote mode: reconnect backoff base in ms (default 500). */
    backoffBaseMs?: number;
    /** Remote mode: reconnect backoff cap in ms (default 30000). */
    backoffCapMs?: number;
    /**
     * WebSocket implementation. Defaults to `globalThis.WebSocket`. Provide for
     * Node without a global WebSocket, or a mock for tests.
     */
    WebSocket?: WebSocketCtor;
    /**
     * Helia mode: enable opportunistic geo enrichment (one short-lived fetch of a
     * reachable remote `/ws/status` per bootstrap node). Default `true`.
     */
    geo?: boolean;
    /** Called with non-fatal errors (fail-open). */
    onError?: (error: unknown) => void;
}
/** Backoff tuning for reconnect delay computation. */
export interface BackoffOptions {
    baseMs: number;
    capMs: number;
    /** Jitter as a fraction (0..1) of the delay, added randomly. Default 0.3. */
    jitter?: number;
}
/**
 * Compute a capped exponential backoff delay with jitter. Pure and
 * deterministic for a given `rng`, so reconnect timing is unit-testable.
 *
 * @param attempt zero-based reconnect attempt count
 */
export declare function computeBackoffDelay(attempt: number, options: BackoffOptions, rng?: () => number): number;
/**
 * Normalize a status feed URL to a `ws`/`wss` URL ending in a `/ws/...` path.
 *
 * - `wss://host` / `ws://host`  → adds `/ws/status` when no path is present
 * - `https://host`             → `wss://host/ws/status`
 * - `http://host`              → `ws://host/ws/status`
 * - `host`                     → `wss://host/ws/status`
 */
export declare function deriveStatusWsUrl(input: string): string;
/**
 * Open a status feed, resolve the first decoded frame, then close. Rejects on
 * timeout, socket error, or close-before-frame. Exported for reuse and testing.
 */
export declare function fetchNodeStatusOnce(url: string, webSocketCtor?: WebSocketCtor, timeoutMs?: number): Promise<NodeStatusSetView>;
/**
 * Create a node status client. Supply `url` for remote mode (a node's
 * `/ws/status` feed) or `helia` for local client-side assembly. When both are
 * given, remote mode wins.
 */
export declare function createNodeStatusClient(options: NodeStatusClientOptions): NodeStatusClient;
//# sourceMappingURL=client.d.ts.map