"use client";

import { AnimatePresence, motion } from "motion/react";
import Image from "next/image";
import {
	type ReactNode,
	useCallback,
	useEffect,
	useId,
	useRef,
	useState,
} from "react";
import { mobileMenuVariants } from "@/lib/motion";

interface MobileNavProps {
	children: ReactNode;
	menuLabel?: string;
	closeLabel?: string;
	brandLabel?: string;
}

export function MobileNav({
	children,
	menuLabel = "Open menu",
	closeLabel = "Close menu",
	brandLabel = "",
}: MobileNavProps) {
	const [open, setOpen] = useState(false);
	const detailsRef = useRef<HTMLDivElement>(null);
	const menuRef = useRef<HTMLDivElement>(null);
	const toggleRef = useRef<HTMLButtonElement>(null);
	const prevFocusRef = useRef<HTMLElement | null>(null);
	const menuId = useId();

	const handleEscape = useCallback(
		(e: KeyboardEvent) => {
			if (e.key === "Escape" && open) {
				setOpen(false);
				(prevFocusRef.current ?? toggleRef.current)?.focus();
			}
		},
		[open],
	);

	useEffect(() => {
		document.addEventListener("keydown", handleEscape);
		return () => document.removeEventListener("keydown", handleEscape);
	}, [handleEscape]);

	// Initial focus, scroll-lock, click-outside close, focus restore.
	useEffect(() => {
		if (!open) return;
		prevFocusRef.current =
			document.activeElement instanceof HTMLElement
				? document.activeElement
				: null;
		menuRef.current
			?.querySelector<HTMLElement>(
				'a[href], button:not([disabled]), [tabindex]:not([tabindex="-1"])',
			)
			?.focus();
		const prevOverflow = document.body.style.overflow;
		document.body.style.overflow = "hidden";

		function handlePointerDown(e: PointerEvent) {
			if (
				menuRef.current &&
				!menuRef.current.contains(e.target as Node) &&
				!toggleRef.current?.contains(e.target as Node)
			) {
				setOpen(false);
			}
		}
		document.addEventListener("pointerdown", handlePointerDown);
		return () => {
			document.body.style.overflow = prevOverflow;
			document.removeEventListener("pointerdown", handlePointerDown);
			(prevFocusRef.current ?? toggleRef.current)?.focus();
		};
	}, [open]);

	useEffect(() => {
		if (!open) return;
		const menu = menuRef.current;
		if (!menu) return;

		const focusableSelector =
			'a[href], button:not([disabled]), textarea, input, select, [tabindex]:not([tabindex="-1"])';

		function handleTab(e: KeyboardEvent) {
			if (e.key !== "Tab" || !menu) return;
			const focusable = Array.from(
				menu.querySelectorAll<HTMLElement>(focusableSelector),
			);
			if (focusable.length === 0) return;
			const first = focusable[0];
			const last = focusable[focusable.length - 1];

			if (e.shiftKey) {
				if (document.activeElement === first) {
					e.preventDefault();
					last.focus();
				}
			} else {
				if (document.activeElement === last) {
					e.preventDefault();
					first.focus();
				}
			}
		}

		menu.addEventListener("keydown", handleTab);
		return () => menu.removeEventListener("keydown", handleTab);
	}, [open]);

	return (
		<div ref={detailsRef} className="group relative md:hidden">
			<button
				ref={toggleRef}
				type="button"
				onClick={() => setOpen((o) => !o)}
				className="list-none cursor-pointer flex items-center justify-center w-11 h-11 rounded-xl shrink-0
					transition-colors duration-150
					hover:bg-[color-mix(in_srgb,var(--color-primary)_12%,transparent)]
					active:scale-[0.96]
					focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-primary-readable,var(--color-primary))] focus-visible:ring-offset-2 focus-visible:ring-offset-[var(--color-navbar)]"
				aria-label={open ? closeLabel : menuLabel}
				aria-expanded={open}
				aria-haspopup="dialog"
				aria-controls={menuId}
			>
				<motion.svg
					className="w-6 h-6"
					animate={{ rotate: open ? 90 : 0 }}
					transition={{ duration: 0.2 }}
					viewBox="0 0 24 24"
					fill="none"
					stroke="currentColor"
					strokeWidth="2"
					strokeLinecap="round"
					strokeLinejoin="round"
				>
					{open ? (
						<>
							<line x1="18" y1="6" x2="6" y2="18" />
							<line x1="6" y1="6" x2="18" y2="18" />
						</>
					) : (
						<>
							<line x1="4" y1="7" x2="20" y2="7" />
							<line x1="4" y1="12" x2="20" y2="12" />
							<line x1="4" y1="17" x2="20" y2="17" />
						</>
					)}
				</motion.svg>
			</button>

			<AnimatePresence>
				{open && (
					<motion.div
						id={menuId}
						role="dialog"
						aria-modal="true"
						aria-label={brandLabel || "Navigation menu"}
						className="absolute left-0 top-full mt-2 w-[min(88vw,360px)] z-50 origin-top-left"
						style={{ backgroundColor: "transparent" }}
						variants={mobileMenuVariants}
						initial="hidden"
						animate="visible"
						exit="exit"
					>
						<div
							ref={menuRef}
							className="flex flex-col gap-y-1 p-2 rounded-2xl border shadow-xl max-h-[calc(100dvh-5rem)] overflow-y-auto overscroll-contain
							bg-[var(--color-dropdown,var(--color-surface,#fff))]"
							style={{
								borderColor:
									"color-mix(in srgb, var(--color-text-muted) 12%, transparent)",
								boxShadow:
									"0 12px 40px color-mix(in srgb, rgb(0 0 0) 22%, transparent)",
							}}
						>
							<div
								className="flex items-center gap-2 px-3 py-2 mb-1 rounded-xl"
								style={{
									backgroundColor:
										"color-mix(in srgb, var(--color-primary) 12%, transparent)",
								}}
							>
								<Image
									src="/assets/images/icons/navigation/home.png"
									alt=""
									width={22}
									height={22}
									className="shrink-0"
								/>
								<span
									className="text-sm font-extrabold uppercase tracking-wide"
									style={{
										color:
											"var(--color-navbar-text-readable, var(--color-text))",
									}}
								>
									{brandLabel}
								</span>
								<span className="ml-auto text-[11px] font-semibold uppercase tracking-wider opacity-75">
									{closeLabel}
								</span>
							</div>

							{children}
						</div>
					</motion.div>
				)}
			</AnimatePresence>
		</div>
	);
}