/**
 * Mapping between Core's server-side message versions and this transcript's indices.
 *
 * Core stores the alternatives created by editing a turn as archived branches, addressed by the
 * user turn they hang off (`forkUserOrdinal`) rather than by transcript position — position is not
 * stable across a fork, since everything after the anchor is archived and restored wholesale. Both
 * functions here translate between that addressing and the indices the widget renders, and both are
 * pure so the edge cases (a turn with no id of its own, a fork whose anchor is currently archived)
 * are testable without a server.
 *
 * Ported from Core's `shared/lib/branchPager.js` and `shared/lib/sessionEditing.js` so the widget's
 * ‹ n/m › control resolves to the same turn as the app's.
 */
import type { MessageType } from '@/widget/types';
import type { TorukSessionBranchGroup, TorukSessionMessage } from '@/sessions/sessions.types';
/** Pager state for one user turn: 1-based position among its versions. */
export type BranchPager = {
    current: number;
    total: number;
    /** The message the fork hangs off, as the switch call needs it. Null at the first turn. */
    forkAfterMessageId: string | null;
};
/**
 * Attach each version group to the transcript index of the user turn it belongs to.
 *
 * Groups are keyed by ordinal, so the walk counts user turns rather than trusting positions: a
 * transcript may open with a welcome turn the server never stored, which would put every index one
 * step out if they were compared directly.
 */
export declare function buildBranchPagerByIndex(groups: readonly TorukSessionBranchGroup[] | undefined, messages: readonly MessageType[] | undefined): Record<number, BranchPager>;
/**
 * Find the stored message id to fork at when editing the turn at `index`.
 *
 * A turn sent in this page's lifetime has no id of its own — the widget appends it locally and only
 * the *answer* comes back with one — so the id has to be recovered from the persisted rows. In
 * order of confidence:
 *
 *   1. the turn's own id, when it was loaded from Core rather than typed here;
 *   2. the row before this turn's answer, whose id the streaming response did return;
 *   3. the row at the same user-turn ordinal, when its text still matches;
 *   4. a content match, but only when exactly one row could be meant.
 *
 * Returning null means "do not fork": better to leave the conversation whole than to archive the
 * wrong half of it.
 */
export declare function resolveEditAnchorId(rows: readonly TorukSessionMessage[] | undefined, messages: readonly MessageType[] | undefined, index: number): string | null;