/**
 * Base Vector Adapter
 *
 * Abstract base class for vector database adapters.
 * All adapters (Pinecone, Qdrant, Weaviate, etc.) extend this class.
 */
import { VectorDBType, DistanceMetric, VectorFeature, IVectorConnectionResult, IVector, IUpsertVectorsOptions, IUpsertVectorsResult, IQueryVectorsOptions, IQueryVectorsResult, IFetchVectorsOptions, IFetchVectorsResult, IUpdateVectorOptions, IUpdateVectorResult, IDeleteVectorsOptions, IDeleteVectorsResult, IListVectorsOptions, IListVectorsResult, IListNamespacesResult, IVectorIndexInfo, ICreateIndexOptions, ICreateIndexResult, IDeleteIndexOptions, IDeleteIndexResult, IVectorIndexStats } from '../types';
/**
 * Adapter connection options
 */
export interface IAdapterConnectionOptions {
    /** API endpoint URL */
    endpoint: string;
    /** API key */
    apiKey?: string;
    /** Index/collection name */
    index: string;
    /** Namespace (for multi-tenancy) */
    namespace?: string;
    /** Vector dimensions */
    dimensions: number;
    /** Distance metric */
    metric?: DistanceMetric;
    /** Cloud region */
    region?: string;
    /** Additional options */
    options?: Record<string, unknown>;
}
/**
 * Abstract base adapter for vector databases
 */
export declare abstract class BaseVectorAdapter {
    /** Database type */
    abstract readonly type: VectorDBType;
    /** Whether connected */
    protected _connected: boolean;
    /** Connection options */
    protected connectionOptions: IAdapterConnectionOptions | null;
    /** Maximum retry attempts for auto-reconnection */
    protected maxRetries: number;
    /** Flag to indicate if a reconnection is in progress */
    private reconnecting;
    /**
     * Get connected status
     */
    get connected(): boolean;
    /**
     * Execute an operation with automatic retry on connection errors.
     * This handles transient connection timeouts and disconnects silently.
     */
    protected executeWithRetry<T>(operation: () => Promise<T>, retries?: number): Promise<T>;
    /**
     * Check if an error is a connection-related error
     */
    protected isConnectionError(error: any): boolean;
    /**
     * Attempt to reconnect to the vector database
     */
    protected attemptReconnect(): Promise<void>;
    /**
     * Get current namespace
     */
    get namespace(): string | undefined;
    /**
     * Get configured dimensions
     */
    get dimensions(): number;
    /**
     * Get configured metric
     */
    get metric(): DistanceMetric;
    /**
     * Connect to the vector database
     */
    abstract connect(options: IAdapterConnectionOptions): Promise<IVectorConnectionResult>;
    /**
     * Disconnect from the vector database
     */
    abstract disconnect(): Promise<void>;
    /**
     * Test connection health
     */
    abstract testConnection(): Promise<boolean>;
    /**
     * Upsert vectors (insert or update)
     */
    abstract upsert(options: IUpsertVectorsOptions): Promise<IUpsertVectorsResult>;
    /**
     * Query vectors by similarity
     */
    abstract query(options: IQueryVectorsOptions): Promise<IQueryVectorsResult>;
    /**
     * Fetch vectors by ID
     */
    abstract fetch(options: IFetchVectorsOptions): Promise<IFetchVectorsResult>;
    /**
     * Update a single vector
     */
    abstract update(options: IUpdateVectorOptions): Promise<IUpdateVectorResult>;
    /**
     * Delete vectors
     */
    abstract delete(options: IDeleteVectorsOptions): Promise<IDeleteVectorsResult>;
    /**
     * List vector IDs
     */
    abstract list(options: IListVectorsOptions): Promise<IListVectorsResult>;
    /**
     * List available namespaces
     */
    abstract listNamespaces(): Promise<IListNamespacesResult>;
    /**
     * Delete a namespace
     */
    abstract deleteNamespace(namespace: string): Promise<void>;
    /**
     * Describe the current index
     */
    abstract describeIndex(): Promise<IVectorIndexInfo>;
    /**
     * Get index statistics
     */
    abstract getIndexStats(): Promise<IVectorIndexStats>;
    /**
     * Create a new index
     */
    abstract createIndex(options: ICreateIndexOptions): Promise<ICreateIndexResult>;
    /**
     * Delete an index
     */
    abstract deleteIndex(options: IDeleteIndexOptions): Promise<IDeleteIndexResult>;
    /**
     * List all indexes
     */
    abstract listIndexes(): Promise<IVectorIndexInfo[]>;
    /**
     * Check if a feature is supported
     */
    abstract supportsFeature(feature: VectorFeature): boolean;
    /**
     * Validate vector dimensions
     */
    protected validateDimensions(vectors: IVector[]): void;
    /**
     * Normalize a vector to unit length (for cosine similarity)
     */
    protected normalizeVector(vector: number[]): number[];
    /**
     * Calculate cosine similarity between two vectors
     */
    protected cosineSimilarity(a: number[], b: number[]): number;
    /**
     * Calculate Euclidean distance between two vectors
     */
    protected euclideanDistance(a: number[], b: number[]): number;
    /**
     * Calculate dot product between two vectors
     */
    protected dotProduct(a: number[], b: number[]): number;
    /**
     * Calculate similarity based on configured metric
     */
    protected calculateSimilarity(a: number[], b: number[]): number;
    /**
     * Generate a unique ID
     */
    protected generateId(): string;
}
export default BaseVectorAdapter;