import { AuthStatus, ChatStatus, Message, MessageSource, SSEEvent } from '../models/types';
/**
 * Pure function — Functional Core.
 * Applies an SSE event to the current messages array, producing a new array.
 * Only the target assistant message is modified.
 *
 * Event types come from the Agent contract:
 *   delta         — append incremental text chunk (event.content)
 *   error         — stop streaming + surface error in bubble
 *   end           — stop streaming cleanly
 *   status        — observational, ignored
 *   metrics       — observational, ignored
 *   visual_result — not rendered by this widget, ignored
 */
export declare function applySSEEvent(messages: Message[], assistantId: string, event: SSEEvent): Message[];
/**
 * Pure function — Functional Core.
 * Normalizes a `sources` SSE event into the message model. The exact payload
 * shape is unconfirmed (spec §3.3), so this tolerates the plausible variants:
 * the list under `sources` or `content`, as an array or a JSON string; items
 * as `{ title?, url|link|href }` objects or plain strings. Anything it cannot
 * understand yields [] — absence of sources must never break the chat.
 *
 * Only http(s) URLs survive (a javascript: URL from a compromised stream must
 * not become a clickable link); URL-less items are kept as plain citations.
 */
export declare function extractSources(event: SSEEvent): MessageSource[];
/**
 * Pure function — Functional Core.
 * The input is locked while a message is in flight and on every auth state
 * where the chat is not usable ('consent' included — the opt-in screen gates
 * the chat). 'idle' keeps the input enabled so the empty state doesn't flash
 * disabled before auth starts.
 */
export declare function isInputDisabled(chatStatus: ChatStatus, authStatus: AuthStatus): boolean;
/**
 * Pure function — Functional Core.
 * "Nova conversa" is offered only while the chat is usable — never from
 * blocked/error/consent, which would be an escape hatch around those gates.
 */
export declare function canStartNewSession(authStatus: AuthStatus): boolean;