/**
 * Structured errors for the shared font module, following the repo convention
 * (see root CLAUDE.md "Structured errors"): a plain `Error` with a
 * semver-stable `code` and JSON-serializable `details` (with `details.reason`
 * as the fine grain). Branch on `err.code`/`err.details.reason`, never on the
 * message. The factory lives in @polotno/core/errors.
 *
 * This module owns the font-domain classification. The reasons match the
 * canonical `FONT_FAILED` table so consumers (pdf-export, polotno-node) can
 * re-surface them unchanged:
 *   - 'not-found'    — the family isn't registered and isn't a Google font
 *                      (HTTP 4xx / empty Google response). The font does not
 *                      exist; retrying will not help.
 *   - 'fetch-failed' — a genuine transport failure (offline, DNS, TLS, or
 *                      5xx/429 that survived all retries). Distinct from
 *                      'not-found' so callers can say "network problem" vs
 *                      "unknown font".
 *   - 'decode-failed'— bytes were fetched but aren't a valid font.
 *   - 'timeout'      — the fetch didn't resolve within the timeout budget.
 */
import { type FontFailedReason, type PolotnoError as CorePolotnoError, type PolotnoErrorDetailsMap, type TypedPolotnoError } from '../errors.js';
export type { FontFailedReason };
export type PolotnoErrorCode = 'FONT_FAILED' | 'FETCH_FAILED';
export type PolotnoError = CorePolotnoError<PolotnoErrorCode>;
export declare const polotnoError: TypedPolotnoError<PolotnoErrorCode>;
/** The `FONT_FAILED` fields the caller supplies; `reason` is injected. */
type FontFailedDetails = Omit<PolotnoErrorDetailsMap['FONT_FAILED'], 'reason'>;
export declare function fontFailed(reason: FontFailedReason, message: string, details?: FontFailedDetails, cause?: unknown): PolotnoError;
/** True for our transport-level `FETCH_FAILED` (from `fetchFontResource`). */
export declare function isFetchFailed(err: unknown): err is PolotnoError;
export declare function isFontFailed(err: unknown): err is PolotnoError;