/**
 * @fileoverview Core utility functions for the Saasflare design system.
 * @module @saasflare/ui/lib/utils
 *
 * Deliberately NO "use client": these are pure functions, safe in React
 * Server Components. Client-coupled helpers live in lib/context.ts and
 * lib/hooks.ts.
 *
 * @example
 * import { cn, composeEventHandlers } from '@saasflare/ui';
 */
import { type ClassValue } from 'clsx';
import type * as React from 'react';
/**
 * Merges class names with Tailwind CSS conflict resolution.
 * Combines clsx conditional logic with tailwind-merge deduplication.
 *
 * @param inputs - Class values (strings, objects, arrays, undefined)
 * @returns Merged and deduplicated class string
 *
 * @example
 * cn('p-4 bg-red-500', 'bg-blue-500')   // → 'p-4 bg-blue-500'
 * cn('text-sm', isLarge && 'text-lg')    // conditional classes
 * cn('mt-2', className)                  // safe forwarding
 */
export declare function cn(...inputs: ClassValue[]): string;
/**
 * Merges multiple refs into a single callback ref.
 * Essential for components that forward a ref while also needing an internal one.
 *
 * @example
 * const Component = forwardRef<HTMLDivElement>((props, ref) => {
 *   const internalRef = useRef<HTMLDivElement>(null);
 *   return <div ref={mergeRefs(ref, internalRef)} />;
 * });
 */
export declare function mergeRefs<T>(...refs: (React.Ref<T> | undefined)[]): React.RefCallback<T>;
/**
 * Composes two event handlers, respecting `preventDefault()`.
 * The internal handler is skipped if the external one calls `preventDefault()`.
 *
 * @param external - Consumer-provided handler (runs first)
 * @param internal - Component-internal handler (skipped if default prevented)
 *
 * @example
 * <button
 *   onClick={composeEventHandlers(props.onClick, () => {
 *     setOpen((o) => !o);
 *   })}
 * />
 */
export declare function composeEventHandlers<E>(external: ((event: E) => void) | undefined, internal: (event: E) => void): (event: E) => void;