import { DotNetObjectReference } from "../blazor-ref/index";
/**
 * Supplies the request headers for a call made on the host's behalf. Returning a promise lets the
 * host refresh an access token before answering.
 */
export type RequestHeadersProvider = () => Promise<object | null | undefined> | object | null | undefined;
/**
 * What a component needs in order to build the headers for any request it makes itself — the
 * vehicle lookup, but also the follow-up calls that used to reuse a stale snapshot: the trace
 * fetches, the claim submission, the unauthorized campaign lookup.
 */
export interface RequestHeadersSource {
    /** Static headers the host set on the element. The floor every request starts from. */
    headers: object;
    /** The headers the host passed with the most recent fetchVin call. */
    lastRequestHeaders?: object;
    /** A host callback that answers with the current headers, asked on every request. */
    requestHeadersProvider?: RequestHeadersProvider;
    /** Name of a [JSInvokable] method on the Blazor reference that answers with the current headers. */
    blazorRequestHeadersProvider?: string;
    blazorRef?: DotNetObjectReference;
}
/**
 * The headers for a request the component is about to make.
 *
 * The token a Blazor host hands over with `fetchVin(vin, headers)` is a snapshot: it is refreshed
 * the moment the user searches, and not again. A trace opened twenty minutes later used to carry
 * that same expired bearer, because it read the `headers` prop instead of asking the host. Every
 * request now resolves its headers through here, freshest source first:
 *
 * 1. `explicit` — headers passed with this very call (a `fetchVin(vin, headers)`), which are also
 *    remembered as `lastRequestHeaders` for the follow-up calls;
 * 2. the host's provider — a JavaScript callback, or a `[JSInvokable]` Blazor method — which can
 *    refresh the token before answering;
 * 3. `lastRequestHeaders`, then the static `headers` prop.
 *
 * The identity props (`cityId`, `userId`, …) are mapped onto their header names last, exactly as
 * the vehicle lookup itself has always done, so a follow-up call carries the same context.
 */
export declare const resolveRequestHeaders: (context: RequestHeadersSource & Record<string, any>, explicit?: object) => Promise<Record<string, string>>;