/**
 * Availability-first search mode resolution
 * (docs/hybrid-retrieval-design.md, Decision 4).
 *
 * No clever query router: with a hot local daemon, running both retrievers
 * costs one extra embedding query, while misrouting costs recall. `auto`
 * therefore means hybrid whenever the index is available, dropping to lexical
 * only on strong lexical signals. Requested semantic/hybrid degrade to
 * lexical (with a recorded reason) when the index is unavailable — never an
 * error, unlike the old semantic_search tool.
 */
import type { ResolvedSearchMode, SearchMode } from "./types.js";
export interface ModeResolution {
    mode: ResolvedSearchMode;
    /** Set when the resolved mode is a forced degradation of the request. */
    degradedReason?: string;
}
/**
 * Regex metacharacters *outside* any quoted segment — the only remaining
 * signal that the caller wants exact matching rather than ranked discovery.
 *
 * Being quoted is deliberately NOT such a signal any more. It used to route
 * every quoted query to lexical-only, which is where all ten error-fragment
 * queries in the gold set land, and lexical is the worst leg for them: R@1
 * 0.000 and MRR 0.483, against 0.600 and 0.800 for the same queries in
 * hybrid. Recall survived the routing but rank did not, and rank is what an
 * agent reads.
 *
 * Metacharacters inside a quoted segment carry no information either, because
 * `buildLexicalQueryPlan` searches a quoted segment verbatim — it escapes the
 * content, so `"initTheme() first."` is matched literally and its parentheses
 * say nothing about the caller's intent. Strip quoted spans before looking.
 *
 * Path-like queries also do NOT count: the eval gate showed them scoring 0%
 * lexically (content grep cannot find a file by its own name) and far better
 * in hybrid, where the embedding side and the reranker's path-affinity signal
 * carry them.
 */
export declare function hasStrongLexicalSignals(query: string): boolean;
export declare function resolveSearchMode(query: string, requested: SearchMode, embedAvailable: boolean, embedUnavailableReason?: string): ModeResolution;
//# sourceMappingURL=mode.d.ts.map