import { clsx, type ClassValue } from "clsx";
import { twMerge } from "tailwind-merge";

export function cn(...inputs: ClassValue[]) {
	return twMerge(clsx(inputs));
}

// relativeTime renders a compact "Xs/Xm/Xh/Xd ago" label for freshness
// indicators (health checks, live event timestamps, etc).
export function relativeTime(iso: string | null | undefined): string {
	if (!iso) return "never";
	const ms = Date.now() - new Date(iso).getTime();
	if (ms < 0) return "just now";
	const s = Math.floor(ms / 1000);
	if (s < 60) return `${s}s ago`;
	const m = Math.floor(s / 60);
	if (m < 60) return `${m}m ago`;
	const h = Math.floor(m / 60);
	if (h < 24) return `${h}h ago`;
	const d = Math.floor(h / 24);
	return `${d}d ago`;
}

// Truncates long slugs/names in the middle (keeping the "type:" prefix and
// the tail visible) rather than at the end — for slugs the distinguishing
// part is often at both ends, e.g. "investigation:nomos/dragonfly-memlock-…"
// vs "…rlimit-type-8-in-unprivileged-lxcs".
export function truncateMiddle(s: string, maxLen = 36): string {
	if (s.length <= maxLen) return s;
	const keep = Math.floor((maxLen - 1) / 2);
	return `${s.slice(0, keep)}…${s.slice(-keep)}`;
}

// debounce wraps fn so rapid calls (e.g. keystrokes in a filter input)
// collapse into one invocation after `wait`ms of silence.
export function debounce<T extends (...args: never[]) => void>(fn: T, wait = 300): T {
	let timer: ReturnType<typeof setTimeout> | undefined;
	return ((...args: Parameters<T>) => {
		clearTimeout(timer);
		timer = setTimeout(() => fn(...args), wait);
	}) as T;
}

// eslint-disable-next-line @typescript-eslint/no-explicit-any
export type WithoutChild<T> = T extends { child?: any } ? Omit<T, "child"> : T;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export type WithoutChildren<T> = T extends { children?: any } ? Omit<T, "children"> : T;
export type WithoutChildrenOrChild<T> = WithoutChildren<WithoutChild<T>>;
export type WithElementRef<T, U extends HTMLElement = HTMLElement> = T & { ref?: U | null };