import type { NixTemplate } from "@deijose/nix-js";
export interface StreamBoundaryOptions<T> {
    /** Fallback content shown while the promise resolves. */
    fallback: NixTemplate;
    /** Promise that resolves to a NixTemplate. */
    promise: Promise<T>;
    /** Renders the resolved value to a NixTemplate. */
    children: (value: T) => NixTemplate;
}
/** Per-request boundary registry. */
interface BoundaryContext {
    boundaries: Map<string, {
        promise: Promise<unknown>;
        children: (value: unknown) => NixTemplate;
    }>;
}
/**
 * Gets the current per-request boundary context, if any.
 * Used by the streaming response to collect boundaries for later resolution.
 */
export declare function getCurrentBoundaryContext(): BoundaryContext | undefined;
/**
 * Runs a function within a per-request boundary context.
 * Used by the SSR streaming pipeline to collect boundaries.
 */
export declare function withBoundaryContext<T>(fn: () => T): T;
/**
 * Builds the fallback HTML wrapper for a boundary ID.
 * The fallback content is wrapped in a `<div>` with the boundary ID so the
 * browser can find it and replace it when the resolved content arrives.
 *
 * (v2.1 — Fix #4: real Suspense streaming with `<template>` replacement)
 */
export declare function buildFallbackHtml(boundaryId: string, fallbackHtml: string): string;
/**
 * Builds the resolved content chunk for a boundary ID.
 * Emits a `<template>` element with the resolved content, followed by a
 * `<script>` that replaces the fallback div with the template content
 * in-place. This is real Suspense streaming — the browser swaps the DOM
 * node without a full re-render.
 *
 * (v2.1 — Fix #4: real Suspense streaming with `<template>` replacement)
 */
export declare function buildResolvedChunk(boundaryId: string, resolvedHtml: string): string;
/**
 * Creates a stream boundary. During SSR, emits the fallback and registers the
 * promise for later resolution by the streaming pipeline. During SSG, the
 * build awaits all boundaries before writing HTML.
 *
 * The boundary ID is deterministic per-request via crypto.randomUUID().
 */
export declare function streamBoundary<T>(options: StreamBoundaryOptions<T>): NixTemplate;
export {};