import type { FileSystemAdapter } from "../../../platform/adapters/base.js";
import type { HandlerContext, HandlerResult } from "../types.js";
interface SourceSnapshotFreshnessReasons {
    readonly ensure: string;
    readonly refreshFallback: string;
    /**
     * Oldest freshness check this caller accepts, in milliseconds. Omit to take
     * the adapter's default lease, which is what sub-resource requests inside one
     * page load want. A document render passes 0, because the snapshot it serves
     * is the one hydration compares against.
     */
    readonly maxAgeMs?: number;
}
export type PreviewDocumentSnapshotReclassifier = () => Promise<HandlerResult>;
export interface PreviewSourceSnapshotMarker {
    readonly identity?: string;
    readonly version?: number;
}
/** Capture a stable, reusable identity for the adapter snapshot. */
export declare function capturePreviewSourceSnapshotMarker(fs: FileSystemAdapter): Promise<PreviewSourceSnapshotMarker | undefined>;
export declare function captureRequiredPreviewSourceSnapshotMarker(fs: FileSystemAdapter, projectSlug: string): Promise<PreviewSourceSnapshotMarker>;
export declare function previewSourceSnapshotMarkersEqual(left: PreviewSourceSnapshotMarker, right: PreviewSourceSnapshotMarker): boolean;
/** Bind already-derived request configuration to its strict source snapshot. */
export declare function seedPreviewDocumentSourceSnapshot(ctx: HandlerContext, marker: PreviewSourceSnapshotMarker): void;
interface RetainedPreviewDocumentSourceSnapshotOptions<T> {
    /** Keep the validated marker available for a later request phase. */
    readonly retainAfterOperation?: (result: T) => boolean;
    /** Re-enter request context before deferred response-body work. */
    readonly runDeferredOperation?: <R>(operation: () => Promise<R>) => Promise<R>;
}
/**
 * Keep a config-bound marker alive across an upstream operation and validate
 * both sides of it. A downstream document handler may release its WeakMap
 * entry before returning through project middleware, so the retained value is
 * the authority for the final check.
 */
export declare function runWithRetainedPreviewDocumentSourceSnapshot<T>(ctx: HandlerContext, operation: () => Promise<T>, options?: RetainedPreviewDocumentSourceSnapshotOptions<T>): Promise<T>;
/** Establish strict freshness before API/page ownership is classified. */
export declare function preparePreviewDocumentSourceSnapshot(ctx: HandlerContext, reclassify?: PreviewDocumentSnapshotReclassifier): Promise<void>;
/**
 * Return the prepared classifier only when its page/API decision has become
 * stale. This probe never refreshes an unprepared direct SSR request, which
 * lets memory-pressure shedding stay cheap without hiding a newly API-owned
 * route behind an SSR 503.
 */
export declare function reclassifyPreviewDocumentSourceSnapshotIfChanged(ctx: HandlerContext): Promise<PreviewDocumentSnapshotReclassifier | undefined>;
/** Validate and release the marker retained across one document render. */
export declare function finishPreviewDocumentSourceSnapshot(ctx: HandlerContext): Promise<PreviewDocumentSnapshotReclassifier | undefined>;
/**
 * Reuse a strict snapshot prepared by the API/page classifier, or return the
 * continuation that can classify the current generation again.
 */
export declare function ensurePreviewDocumentSourceSnapshot(ctx: HandlerContext): Promise<PreviewDocumentSnapshotReclassifier | undefined>;
/**
 * Establish the current mutable source snapshot before request routing or
 * rendering reads project files.
 *
 * Throws when the source can go stale and the adapter offers no way to bring
 * it up to date. Treating that as success is what lets an older snapshot reach
 * hydration, so the request fails instead.
 */
export declare function ensurePreviewSourceSnapshotFresh(ctx: HandlerContext, reasons?: SourceSnapshotFreshnessReasons): Promise<void>;
/** Establish zero-age freshness before loading preview document configuration. */
export declare function ensurePreviewDocumentConfigSourceSnapshotFresh(fs: FileSystemAdapter, projectSlug: string): Promise<void>;
export declare function refreshPreviewSourceSnapshot(ctx: HandlerContext, reason?: string): Promise<void>;
export {};
//# sourceMappingURL=source-snapshot-freshness.d.ts.map