/**
 * OTP (One-Time Password) Authentication Provider
 *
 * Handles OTP-based authentication including:
 * - SMS OTP: One-time passwords sent via SMS
 * - Email OTP: One-time passwords sent via email
 * - Magic Links: Login links sent via email
 *
 * P1 Feature: OTP-based authentication is widely used for 2FA and passwordless flows
 */
import type { AuthProvider, AuthResult } from './index.js';
import { type OTPAuthConfig } from './index.js';
/**
 * OTP delivery method
 */
export type OTPDeliveryMethod = 'sms' | 'email' | 'magic_link';
/**
 * Generates a random OTP code
 * @param digits Number of digits (default 6)
 */
export declare function generateOTP(digits?: number): string;
/**
 * Validates OTP format
 * @param code OTP code to validate
 * @param digits Expected number of digits
 */
export declare function validateOTPFormat(code: string, digits?: number): boolean;
/**
 * Generates a magic link URL
 * @param baseUrl Base URL of the application
 * @param token Authentication token
 * @param email User email
 */
export declare function generateMagicLink(baseUrl: string, token: string, email: string): string;
/**
 * Extracts token from magic link URL
 * @param url Magic link URL
 */
export declare function extractTokenFromMagicLink(url: string): string | null;
/**
 * OTP Authentication Provider
 */
export declare class OTPProvider implements AuthProvider<OTPAuthConfig> {
    readonly type: "otp";
    private otpStates;
    private maxAttempts;
    authenticate(config: OTPAuthConfig): Promise<AuthResult>;
    /**
     * Requests a new OTP to be sent
     */
    requestOTP(config: OTPAuthConfig): Promise<AuthResult>;
    /**
     * Verifies an OTP code
     */
    verifyOTP(config: OTPAuthConfig): Promise<AuthResult>;
    /**
     * Verifies a magic link
     */
    verifyMagicLink(config: OTPAuthConfig): Promise<AuthResult>;
    /**
     * Generates a session token
     */
    private generateSessionToken;
    /**
     * Validates OTP configuration
     */
    validate(config: OTPAuthConfig): Promise<boolean>;
    /**
     * Clears cached OTP state
     */
    clear(config: OTPAuthConfig): Promise<void>;
    /**
     * Gets remaining time for OTP expiration
     */
    getOTPTimeRemaining(destination: string): number | null;
    /**
     * Gets remaining attempts for OTP verification
     */
    getRemainingAttempts(destination: string): number;
    /**
     * Sets maximum verification attempts
     */
    setMaxAttempts(max: number): void;
    /**
     * Clears all OTP states
     */
    clearAllStates(): void;
    private getCacheKey;
}
/**
 * Creates an OTP auth provider instance
 */
export declare function createOTPProvider(): OTPProvider;