/**
 * Shared utility functions for @oxpulse/chat-sdk.
 *
 * Mirror: web/src/lib/api/sdkChat.ts contains equivalent implementations.
 * Keep in sync when modifying either file.
 */
import type { SDKChatErrorCode, TypingEvent, PresenceEvent, ReadReceiptEvent } from './types.js';
/** Callbacks accepted by dispatchTransient — subset of SubscribeArgs / SubscribeOpts. */
export interface TransientCallbacks {
    onTyping?: (event: TypingEvent) => void;
    onPresence?: (event: PresenceEvent) => void;
    onReadReceipt?: (event: ReadReceiptEvent) => void;
}
/**
 * Route a transient SSE event (typing / presence / read_receipt) to the
 * appropriate callback.
 *
 * Single source of truth — imported by both packages/chat-sdk/src/client.ts
 * and web/src/lib/api/sdkChat.ts. Keep in sync with the event shapes emitted
 * by sdk_presence.rs.
 */
export declare function dispatchTransient(evType: string, data: Record<string, unknown>, callbacks: TransientCallbacks): void;
/**
 * ArrayBuffer → standard base64 string (with `+`/`/`, with padding).
 *
 * B2 fix: server uses `base64::engine::general_purpose::STANDARD` which rejects
 * URL-safe characters (`-`, `_`). All sealed payload round-trips MUST use this
 * function so client-produced base64 survives server decode.
 *
 * @deprecated `arrayBufferToBase64url` (URL-safe, no padding) is kept for
 * backward-compat with any existing callers outside this package; new code
 * MUST use `arrayBufferToBase64`.
 */
export declare function arrayBufferToBase64(buf: ArrayBuffer): string;
/** base64 (standard or url-safe, with or without padding) → ArrayBuffer. */
export declare function base64ToArrayBuffer(b64: string): ArrayBuffer;
/** Map an HTTP status code to an SDKChatErrorCode. */
export declare function httpStatusToCode(status: number): SDKChatErrorCode;
/**
 * Reconnect backoff with ±20% jitter and a configurable schedule.
 *
 * `base = schedule[attempt] ?? fallback`, then `Math.round(base * (0.8 +
 * Math.random() * 0.4))` spreads concurrent client retries across a window so
 * a server restart with N peers doesn't trigger N synchronised retry waves at
 * T+1s, T+2s…
 *
 * Same shape as `web/src/lib/reconnect-backoff.ts` — mirrored here as the
 * canonical SDK implementation. `backoffMs` is a thin opt-out wrapper over
 * this function using the default exponential schedule + 30 s fallback.
 *
 * @param attempt   0-based reconnect attempt index.
 * @param schedule  readonly base delays indexed by attempt; defaults to the
 *                  exponential `[1000, 2000, 4000, 8000, 16000, 30000]`.
 * @param fallback  base delay used once `attempt` exceeds `schedule.length`;
 *                  defaults to `30000`.
 * @returns jittered delay in ms (±20% of the base).
 */
export declare function backoffWithJitter(attempt: number, schedule?: readonly number[], fallback?: number): number;
/**
 * Returns jittered backoff in ms. Caps at 30 s.
 *
 * Thin wrapper over `backoffWithJitter` using the default exponential schedule
 * + 30 s fallback. Signature unchanged (backward compatible) — existing
 * callers (`client.ts`) are unaffected.
 */
export declare function backoffMs(attempt: number): number;
/**
 * Generate a UUID v4 using a cryptographically-secure RNG.
 *
 * F13 (fail-closed CSPRNG): `crypto.randomUUID` is preferred; otherwise the 16 random bytes
 * come from `crypto.getRandomValues`. When NEITHER is available we THROW rather than fall back
 * to `Math.random()` — a non-CSPRNG would be a SILENT security downgrade for any caller that
 * treats the id as unpredictable, and this is a public export (index.ts) usable for nonces /
 * session ids, not only message ids. On every supported runtime — a browser secure origin, or
 * Node >= 18 with WebCrypto (`globalThis.crypto`) — `getRandomValues` is present, so the throw
 * is unreachable in practice; it converts an unsupported/insecure runtime into a loud error
 * instead of weak randomness.
 */
export declare function generateUUID(): string;
//# sourceMappingURL=utils.d.ts.map