import type { IndexFiles } from "../indexer/index-files.js";
import type { IndexCode } from "../indexer/index-code.js";
import type { IndexGraph } from "../indexer/index-graph.js";
import type { SearchResult, CodeChunk, FileRecord } from "../types/index.js";
export type RetrievalMethod = "fts" | "vector" | "symbol" | "refs" | "graph-expand" | "module" | "path" | "upstream";
export declare const EDGE_WEIGHTS: Record<string, number>;
export interface InvestigateHit {
    chunk: CodeChunk;
    file: FileRecord;
    score: number;
    found_by: RetrievalMethod[];
}
export interface InvestigateResult {
    query: string;
    hits: InvestigateHit[];
    budget_used: Record<RetrievalMethod, number>;
}
export interface InvestigateOptions {
    query: string;
    scope?: string;
    budget?: number;
    /**
     * When true, after the four base retrievers run, expand top-20 hits
     * one hop along typed edges (calls / documents / imports / extends)
     * and fuse the expansion as a 5th ranker. Bumps recall on multi-hop
     * questions ("everywhere auth state mutates") at small latency cost.
     * Default: false (P1-9 ships the capability, callers opt in until the
     * eval harness shows it's a strict improvement).
     */
    expandGraph?: boolean;
    /**
     * When true, walk the file-import graph BACKWARD from the top base
     * hits up to depth 2 and add chunks from the heavily-imported parent
     * files (top-decile PageRank) to the candidate pool. Closes the
     * "god-file" recall failure that bench:swe v0.17 surfaced across
     * Express/NestJS/Prisma — central files (lib/router/index.js,
     * packages/core/injector/injector.ts, LibraryEngine.ts) that every
     * feature file imports but no individual query lexically matches.
     * Default: false (v0.18 ships behind the flag, eval harness measures
     * whether it's a strict improvement before the default flips).
     */
    expandUpstream?: boolean;
}
/**
 * Multi-signal investigation: runs BM25, vector, symbol lookup, and reference
 * expansion in parallel then RRF-fuses them. Returns hits tagged with which
 * retriever(s) surfaced them, so the agent can see whether a result is
 * semantically + structurally agreed-upon or a single-signal outlier.
 */
export declare function runInvestigate(indexer: IndexFiles & IndexCode & IndexGraph, opts: InvestigateOptions): Promise<InvestigateResult>;
/**
 * Pull likely symbol candidates out of a natural-language query. Splits
 * camelCase / snake_case, drops stopwords and very short tokens. Returns
 * at most 6 to keep investigate bounded.
 */
export declare function extractSymbolTokens(query: string): string[];
/**
 * Format investigate results as a single text block. Mirrors the
 * formatResults shape from hybrid-search so agents get a consistent view.
 */
export declare function formatInvestigate(result: InvestigateResult, maxHits?: number): string;
export type { SearchResult };