/**
 * Upstream Diff Query
 *
 * The toolbar pill and the drawer it opens both read the same change summary.
 * Sharing the key and a stale window means one fetch answers both: the pill has
 * to know the count to decide whether to appear, and opening the drawer reuses
 * that read rather than making its own. Recording a resolution invalidates the
 * key, so the window never holds a summary past a change to it.
 *
 * They also have to agree on what an outcome means, so the read is classified
 * here rather than by each reader: a missing edge and an unreachable check both
 * leave no summary, and they call for opposite things.
 */
import { type ChangeSummary, type P1Client } from '@pantheon-systems/css-client';
export declare const UPSTREAM_DIFF_KEY = "p1-upstream-diff";
export type UpstreamRelationType = 'localization' | 'template';
export declare function upstreamDiffQueryKey(siteId: string, branchId: string, documentId: string, relationType: UpstreamRelationType): (string | undefined)[];
export declare function upstreamDiffQuery(client: P1Client, siteId: string, branchId: string, documentId: string, relationType: UpstreamRelationType): {
    queryKey: (string | undefined)[];
    queryFn: () => Promise<ChangeSummary>;
    retry: false;
    staleTime: number;
};
/** What a reader of the summary has to go on. */
export type UpstreamDiff = {
    state: 'checking';
}
/** The page derives from nothing: there is nothing to reconcile, and nothing to say. */
 | {
    state: 'noEdge';
}
/** The check could not be made, so how far the page has drifted is unknown. */
 | {
    state: 'unavailable';
    message: string;
    retry: () => void;
}
/** A summary to work from. `staleReason` is set when the last refresh failed. */
 | {
    state: 'ready';
    summary: ChangeSummary;
    staleReason: string | null;
};
export declare function useUpstreamDiff(client: P1Client, siteId: string, branchId: string, documentId: string, relationType: UpstreamRelationType): UpstreamDiff;