/**
 * Encoding Utilities
 */
/**
 * Base64 encode a string
 * @param str - String to encode
 * @returns Base64 encoded string
 * @example
 * const encoded = base64Encode("Hello World");
 */
export declare function base64Encode(str: string): string;
/**
 * Base64 decode a string
 * @param str - Base64 encoded string
 * @returns Decoded string
 * @example
 * const decoded = base64Decode("SGVsbG8gV29ybGQ=");
 */
export declare function base64Decode(str: string): string;
/**
 * Encode items array to Base64 JSON string
 * @param items - Array of items
 * @returns Base64 encoded JSON string
 * @example
 * const encoded = encodeItems([
 *   { name: "Product 1", quantity: 1, price: 10.50 }
 * ]);
 */
export declare function encodeItems(items: Array<{
    name: string;
    quantity: number;
    price: number;
}>): string;
/**
 * Encode payout array to Base64 JSON string
 * @param payout - Array of payout distributions
 * @returns Base64 encoded JSON string
 * @example
 * const encoded = encodePayout([
 *   { merchant_id: "ec000003", amount: 5.00 }
 * ]);
 */
export declare function encodePayout(payout: Array<{
    merchant_id: string;
    amount: number;
}>): string;
/**
 * Encode payout for purchase (different format with acc/amt)
 * @param payout - Array of payout distributions with acc/amt format
 * @returns Base64 encoded JSON string
 */
export declare function encodePurchasePayout(payout: Array<{
    acc: string;
    amt: number;
}>): string;
/**
 * Encode callback URL to Base64
 * @param url - Callback URL
 * @returns Base64 encoded URL
 * @example
 * const encoded = encodeCallbackUrl("https://example.com/callback");
 */
export declare function encodeCallbackUrl(url: string): string;
/**
 * Encode return deeplink configuration to Base64 JSON string
 * @param deeplink - Deeplink configuration
 * @returns Base64 encoded JSON string
 * @example
 * const encoded = encodeReturnDeeplink({
 *   success: "myapp://payment/success",
 *   fail: "myapp://payment/fail"
 * });
 */
export declare function encodeReturnDeeplink(deeplink: {
    success?: string;
    fail?: string;
    cancel?: string;
}): string;
/**
 * Encode mobile return deeplink for purchase
 * @param deeplink - Mobile deeplink with iOS and Android schemes
 * @returns Base64 encoded JSON string
 */
export declare function encodeMobileDeeplink(deeplink: {
    ios_scheme?: string;
    android_scheme?: string;
}): string;
/**
 * Encode custom fields to Base64 JSON string
 * @param fields - Custom fields object
 * @returns Base64 encoded JSON string
 * @example
 * const encoded = encodeCustomFields({ orderId: "12345", source: "mobile" });
 */
export declare function encodeCustomFields(fields: Record<string, any>): string;
/**
 * Encode return parameters to Base64 JSON string
 * @param params - Return parameters object
 * @returns Base64 encoded JSON string
 * @example
 * const encoded = encodeReturnParams({ userId: "user123" });
 */
export declare function encodeReturnParams(params: Record<string, any>): string;
/**
 * Encode additional parameters to Base64 JSON string
 * @param params - Additional parameters object
 * @returns Base64 encoded JSON string
 */
export declare function encodeAdditionalParams(params: Record<string, any>): string;