import { Request, Response, NextFunction } from 'express';

/**
 * Configuration for XAPIFi SDK
 */
interface XAPIFiConfig {
    /** Your xAPI-Fi API key */
    apiKey: string;
    /** Solana network to use (default: 'solana') */
    network?: 'solana' | 'solana-devnet';
    /** Custom facilitator URL (optional) */
    facilitatorUrl?: string;
    /** API base URL (default: https://api.xapi-fi.com/v1) */
    apiBaseUrl?: string;
}
/**
 * Options for protecting an endpoint
 */
interface ProtectOptions {
    /** Price in USD for calling this endpoint */
    price: number;
    /** Human-readable description of what this endpoint does */
    description?: string;
    /** Maximum timeout in milliseconds for payment verification */
    maxTimeout?: number;
    /** Custom validation rules */
    customRules?: (req: any) => Promise<boolean>;
}
/**
 * Payment requirements returned in 402 response
 */
interface PaymentRequirements {
    /** Endpoint ID */
    endpointId: string;
    /** Price in USD */
    price: number;
    /** Price in lamports (SOL) */
    priceInLamports: number;
    /** Treasury address to send payment to */
    treasuryAddress: string;
    /** Network to use */
    network: string;
    /** Description of the endpoint */
    description?: string;
}
/**
 * Verified payment information
 */
interface VerifiedPayment {
    /** Whether the payment is valid */
    valid: boolean;
    /** Transaction signature */
    signature?: string;
    /** Amount paid in lamports */
    amount?: number;
    /** Payer address */
    payer?: string;
    /** Error message if invalid */
    error?: string;
}

/**
 * XAPIFi Server SDK
 *
 * Usage:
 * ```typescript
 * const xapi = new XAPIFi({ apiKey: 'your-key' });
 * app.post('/api/generate', xapi.protect({ price: 0.001 }), handler);
 * ```
 */
declare class XAPIFi {
    private config;
    constructor(config: XAPIFiConfig);
    /**
     * Express/Next.js middleware to protect an endpoint with x402 payments
     */
    protect(options: ProtectOptions): (req: Request, res: Response, next: NextFunction) => Promise<Response<any, Record<string, any>> | undefined>;
    /**
     * Get payment requirements for an endpoint
     */
    private getPaymentRequirements;
    /**
     * Verify a payment with the x402 facilitator
     */
    private verifyPayment;
    /**
     * Track analytics event
     */
    private trackAnalytics;
    /**
     * Framework-agnostic handler
     */
    handleRequest(request: any, options: ProtectOptions): Promise<any>;
}

export { type PaymentRequirements, type ProtectOptions, type VerifiedPayment, XAPIFi, type XAPIFiConfig, XAPIFi as default };