import { Node } from './node';
type Metric = 'cosine' | 'euclidean';
export declare class HNSW {
    metric: Metric;
    similarityFunction: (a: number[] | Float32Array, b: number[] | Float32Array) => number;
    d: number | null;
    M: number;
    efConstruction: number;
    efSearch: number;
    levelMax: number;
    entryPointId: number;
    nodes: Map<number, Node>;
    probs: number[];
    /**
     * Creates an in-memory HNSW index.
     */
    constructor(M?: number, efConstruction?: number, d?: number | null, metric?: string, efSearch?: number);
    private getMetric;
    private set_probs;
    private selectLevel;
    private greedySearch;
    private searchLayer;
    private connectNodeAtLevel;
    private addBidirectionalConnection;
    private removeReciprocalLinks;
    private insertNeighbor;
    private selectNeighborsHeuristic;
    private addNodeToGraph;
    /**
     * Adds a single vector to the graph.
     */
    addPoint(id: number, vector: Float32Array | number[]): Promise<void>;
    /**
     * Returns up to k nearest neighbors for the query vector.
     */
    searchKNN(query: Float32Array | number[], k: number, options?: {
        efSearch?: number;
    }): {
        id: number;
        score: number;
    }[];
    /**
     * Rebuilds the graph from the provided data.
     */
    buildIndex(data: {
        id: number;
        vector: Float32Array | number[];
    }[], options?: {
        onProgress?: (current: number, total: number) => void;
        progressInterval?: number;
    }): Promise<void>;
    /**
     * Serializes the current in-memory index.
     */
    toJSON(): {
        M: number;
        efConstruction: number;
        efSearch: number;
        metric: Metric;
        d: number | null;
        levelMax: number;
        entryPointId: number;
        nodes: (number | {
            id: number;
            level: number;
            vector: number[];
            neighbors: number[][];
        })[][];
    };
    /**
     * Restores an index from serialized JSON produced by toJSON().
     */
    static fromJSON(json: any): HNSW;
}
export {};