/**
 * A utility type for handling both synchronous and asynchronous values.
 */
type MaybePromise<T> = T | Promise<T>;
/**
 * Function signature for signal handlers.
 *
 * @param {exitCode} number - The exit code received by the process.
 * @returns {MaybePromise<any>} - A possible promise to handle async cleanup.
 */
type SignalHandler = (exitCode: number) => MaybePromise<any>;
/**
 * Options for configuring an exit hook.
 */
interface ExitOptions {
    /**
     * The number of milliseconds to wait before forcefully exiting the process.
     * @default Infinity
     */
    timeout?: number;
}
/**
 * A function that removes a registered exit hook when invoked.
 */
interface UnsubscribeFn {
    (): void;
}

/**
 * Registers an exit handler that will be called when the process is terminating.
 * The handler receives the exit code and can perform synchronous or asynchronous cleanup.
 *
 * @param handler - The function to execute on exit. Receives the process exit code.
 * @param options - Optional configurations for the exit hook, such as a timeout in milliseconds.
 * @returns A function to unsubscribe and remove the registered exit hook.
 *
 * @example
 * ```ts
 * import { onExit } from 'exit-signal';
 *
 * // Register a cleanup handler
 * const unsubscribe = onExit(async (code) => {
 *   console.log(`Cleaning up before exit with code ${code}`);
 *   await cleanupResources();
 * }, { timeout: 3000 });
 *
 * // Later, if needed, remove the hook
 * unsubscribe();
 * ```
 */
declare function onExit(handler: SignalHandler, options?: ExitOptions): UnsubscribeFn;
/**
 * Initiates a graceful exit by triggering the exit handlers and exiting with code 0.
 * This is equivalent to sending a SIGINT signal programmatically.
 *
 * @example
 * ```ts
 * import { gracefullyExit } from 'exit-signal';
 *
 * // Trigger all registered exit hooks and exit with code 0
 * gracefullyExit();
 * ```
 */
declare function gracefullyExit(): void;

export { gracefullyExit, onExit };