import type { Database } from "./database.js";
import type { Evidence, RetrievalMethod, VerifyResult } from "../types/index.js";
export interface EvidenceInput {
    file: string;
    start_line: number;
    end_line: number;
    commit_sha: string | null;
    chunk_id: number | null;
    symbol: string | null;
    method: RetrievalMethod;
    score: number;
    content_hash: string;
}
export interface StoredEvidence extends EvidenceInput {
    id: string;
    created_at: number;
}
export declare class EvidenceStore {
    private db;
    private insertStmt;
    private getByIdStmt;
    private countStmt;
    private deleteOldStmt;
    private deleteOverflowStmt;
    constructor(db: Database);
    purge(now?: number): number;
    private insertsSincePurge;
    private static readonly PURGE_INTERVAL;
    insert(input: EvidenceInput): string;
    getById(id: string): StoredEvidence | null;
    count(): number;
    /**
     * Convert a stored row back to the public `Evidence` shape used in the
     * tool-response envelope. `chunk_id` / `symbol` are null→undefined'd.
     */
    toEvidence(row: StoredEvidence): Evidence;
}
export declare function hashSpan(content: string): string;
/**
 * Compute a cheap Jaccard-on-tokens similarity between two code spans.
 * Tokens are identifier-ish: `[A-Za-z0-9_]+`. Whitespace + punctuation
 * collapse to token boundaries. 1.0 = identical token bag, 0.0 = disjoint.
 */
export declare function spanSimilarity(a: string, b: string): number;
/**
 * Classify the result of comparing the original evidence span to what's in
 * the file now.
 */
export declare function classifyVerify(opts: {
    fileExists: boolean;
    originalHash: string;
    currentHash: string | null;
    similarity: number | null;
    linesMoved: boolean;
}): VerifyResult["status"];