/**
 * AI streaming response reader.
 *
 * Reads chunks from a `Response`'s body, batches store updates to one
 * per animation frame, strips trailing incomplete HTML tags so partial
 * flash, and parses widget blocks at completion.
 *
 * Pure with respect to the DOM — only writes into the store. The bubble
 * keeps the same id from frame one: the server pre-creates the row and
 * returns the persisted id via the `X-Vtilt-Message-Id` header, so the
 * later Ably echo / DB-update merges into the same row with no remount.
 * On older servers that don't send the header we fall back to the legacy
 * `temp-ai-*` id and upsertMessage's id-swap behaviour.
 */
import type { ChatStore } from "../store/chat-store";
/** Header the server uses to publish the persisted AI message id up-front. */
export declare const AI_MESSAGE_ID_HEADER = "X-Vtilt-Message-Id";
/** Header the server uses to publish the persisted AI message timestamp. */
export declare const AI_MESSAGE_CREATED_AT_HEADER = "X-Vtilt-Message-Created-At";
/** Widget block marker regex: `<!--vtilt:widget:{...}-->` */
export declare const WIDGET_BLOCK_RE: RegExp;
/** Parse `<!--vtilt:widget:{...}-->` markers out of streamed content. */
export declare function parseWidgetBlocks(text: string): Array<{
    type: string;
    params: Record<string, unknown>;
}>;
/**
 * Align the optimistic user row's `created_at` with the server timestamp from
 * stream response headers, then re-sort.
 *
 * The optimistic bubble is stamped with the *client* clock. The AI placeholder
 * uses the *server* clock from `X-Vtilt-Message-Created-At`. When the client
 * clock is ahead of the server, chronological insert places the AI bubble
 * *above* the user question until a full reload. Applying the user ack
 * timestamp before the AI insert keeps local order identical to Postgres.
 */
export declare function applyUserMessageCreatedAtFromHeaders(store: ChatStore, response: Response): void;
interface StreamArgs {
    store: ChatStore;
    response: Response;
    channelId: string;
    tempId?: string;
    /** When aborted, the reader stops and removes its partial bubble. */
    signal?: AbortSignal;
    /** Extra guard for superseded streams (new user send while still reading). */
    isActive?: () => boolean;
    onStreamStart?: (messageId: string) => void;
    onComplete?: (messageId: string) => void;
}
/**
 * Read an AI streaming response into the store. The bubble id is decided
 * once at frame one (persisted id from `X-Vtilt-Message-Id` if the server
 * provided it, otherwise a `temp-ai-*` fallback) and never changes, so
 * the same `MessageBubble` instance receives content updates without
 * re-keying.
 */
export declare function handleStreamingResponse({ store, response, channelId, tempId, signal, isActive, onStreamStart, onComplete, }: StreamArgs): Promise<void>;
/** Remove a single message by id (used to clean up failed temp messages). */
export declare function removeMessageById(store: ChatStore, id: string): void;
export {};