"use client";

import { type LucideIcon, Search, X } from "lucide-react";
import {
	AnimatePresence,
	LayoutGroup,
	motion,
	type Transition,
	useReducedMotion,
} from "motion/react";
import {
	type KeyboardEvent as ReactKeyboardEvent,
	type ReactNode,
	useCallback,
	useEffect,
	useId,
	useLayoutEffect,
	useMemo,
	useRef,
	useState,
} from "react";
import { createPortal } from "react-dom";
import { EASE_OUT, SPRING_LAYOUT } from "@/lib/ease";
import { useOnOpen } from "@/lib/hooks/use-on-open";
import { useRowCursor } from "@/lib/hooks/use-row-cursor";
import { cn } from "@/lib/utils";

// Keeps the Wallet Card feel with a little more time to read the morph.
const SEARCH_MORPH: Transition = {
	type: "spring",
	duration: 0.58,
	bounce: 0.22,
};

// Keep the spring on the shell, but unfold complex clip-path values with the
// same progressive tween as Morph Popover so the content never snaps ahead.
const SEARCH_CLIP_TRANSITION: Transition = {
	duration: 0.32,
	ease: EASE_OUT,
};

export type MorphingSearchItem = {
	id: string;
	title: string;
	description?: string;
	/** Results are grouped in first-seen order; the group name is searchable. */
	group?: string;
	/** Detail content shown for the hovered, focused, or keyboard-active result. */
	preview?: ReactNode;
	keywords?: string[];
	icon?: LucideIcon;
	onSelect?: () => void;
};

export interface MorphingSearchProps {
	items: MorphingSearchItem[];
	placeholder?: string;
	shortcut?: string;
	/** Render the closed trigger as a compact search icon. */
	iconOnly?: boolean;
	emptyMessage?: string;
	open?: boolean;
	defaultOpen?: boolean;
	onOpenChange?: (open: boolean) => void;
	onQueryChange?: (query: string) => void;
	onSelect?: (item: MorphingSearchItem) => void;
	className?: string;
}

type AnchorRect = {
	top: number;
	left: number;
	width: number;
};

function isEditableTarget(target: EventTarget | null) {
	if (!(target instanceof HTMLElement)) return false;
	return (
		target.isContentEditable ||
		target instanceof HTMLInputElement ||
		target instanceof HTMLTextAreaElement ||
		target instanceof HTMLSelectElement
	);
}

export function MorphingSearch({
	items,
	placeholder = "Search",
	shortcut = "f",
	iconOnly = false,
	emptyMessage = "No results found.",
	open: controlledOpen,
	defaultOpen = false,
	onOpenChange,
	onQueryChange,
	onSelect,
	className,
}: MorphingSearchProps) {
	const [internalOpen, setInternalOpen] = useState(defaultOpen);
	const [query, setQuery] = useState("");
	const [mounted, setMounted] = useState(false);
	const [backgroundScrollLocked, setBackgroundScrollLocked] =
		useState(defaultOpen);
	const [anchorRect, setAnchorRect] = useState<AnchorRect>({
		top: 16,
		left: 16,
		width: 288,
	});
	const open = controlledOpen ?? internalOpen;
	const controlled = controlledOpen !== undefined;
	const reduce = useReducedMotion();
	const uid = useId();
	const anchorRef = useRef<HTMLDivElement>(null);
	const triggerRef = useRef<HTMLButtonElement>(null);
	const inputRef = useRef<HTMLInputElement>(null);
	const dialogRef = useRef<HTMLDivElement>(null);
	const listRef = useRef<HTMLDivElement>(null);
	const previewRef = useRef<HTMLElement>(null);
	const previousFocusRef = useRef<HTMLElement | null>(null);
	const wasOpenRef = useRef(open);
	const transition: Transition = reduce ? { duration: 0 } : SPRING_LAYOUT;
	const morphTransition: Transition = reduce ? { duration: 0 } : SEARCH_MORPH;

	const setOpen = useCallback(
		(next: boolean) => {
			if (!controlled) setInternalOpen(next);
			onOpenChange?.(next);
		},
		[controlled, onOpenChange],
	);

	const measureAnchor = useCallback(() => {
		const rect = anchorRef.current?.getBoundingClientRect();
		if (!rect || rect.width === 0) return;
		setAnchorRect({ top: rect.top, left: rect.left, width: rect.width });
	}, []);

	const openSearch = useCallback(() => {
		measureAnchor();
		setBackgroundScrollLocked(true);
		previousFocusRef.current =
			document.activeElement instanceof HTMLElement
				? document.activeElement
				: null;
		setOpen(true);
	}, [measureAnchor, setOpen]);

	const filteredItems = useMemo(() => {
		const needle = query.trim().toLowerCase();
		if (!needle) return items;

		return items.filter((item) =>
			[
				item.title,
				item.description ?? "",
				item.group ?? "",
				...(item.keywords ?? []),
			]
				.join(" ")
				.toLowerCase()
				.includes(needle),
		);
	}, [items, query]);

	const hasGroups = items.some((item) => item.group);
	const hasPreviews = items.some((item) => item.preview != null);
	const grouped = useMemo(() => {
		const groups = new Map<string, MorphingSearchItem[]>();
		for (const item of filteredItems) {
			const key = item.group || "";
			const group = groups.get(key);
			if (group) group.push(item);
			else groups.set(key, [item]);
		}
		let startIndex = 0;
		return Array.from(groups, ([label, entries]) => {
			const group = { label, entries, startIndex };
			startIndex += entries.length;
			return group;
		});
	}, [filteredItems]);
	// Cursor, option ids, and Enter must follow grouped display order.
	const rows = useMemo(
		() => grouped.flatMap((group) => group.entries),
		[grouped],
	);
	const { activeIndex, moveTo, moveActive } = useRowCursor(rows, query);
	const activeItem = rows[activeIndex];

	// The cursor is stamped with the query, so changing it drops the highlight
	// without this having to say so.
	const updateQuery = useCallback(
		(next: string) => {
			setQuery(next);
			onQueryChange?.(next);
		},
		[onQueryChange],
	);

	const closeSearch = useCallback(() => {
		updateQuery("");
		setOpen(false);
	}, [setOpen, updateQuery]);

	useEffect(() => setMounted(true), []);

	useEffect(() => {
		if (open) setBackgroundScrollLocked(true);
	}, [open]);

	useEffect(() => {
		measureAnchor();
		const anchor = anchorRef.current;
		const observer =
			anchor && typeof ResizeObserver !== "undefined"
				? new ResizeObserver(measureAnchor)
				: null;
		if (anchor) observer?.observe(anchor);
		window.addEventListener("resize", measureAnchor);
		document.addEventListener("scroll", measureAnchor, true);
		window.visualViewport?.addEventListener("resize", measureAnchor);
		window.visualViewport?.addEventListener("scroll", measureAnchor);
		return () => {
			observer?.disconnect();
			window.removeEventListener("resize", measureAnchor);
			document.removeEventListener("scroll", measureAnchor, true);
			window.visualViewport?.removeEventListener("resize", measureAnchor);
			window.visualViewport?.removeEventListener("scroll", measureAnchor);
		};
	}, [measureAnchor]);

	useEffect(() => {
		if (!backgroundScrollLocked) return;

		const preventBackgroundWheel = (event: WheelEvent) => {
			const target = event.target;
			if (
				target instanceof Node &&
				(listRef.current?.contains(target) ||
					previewRef.current?.contains(target))
			)
				return;
			event.preventDefault();
		};
		const preventBackgroundTouch = (event: TouchEvent) => {
			const target = event.target;
			if (
				target instanceof Node &&
				(listRef.current?.contains(target) ||
					previewRef.current?.contains(target))
			)
				return;
			event.preventDefault();
		};

		document.addEventListener("wheel", preventBackgroundWheel, {
			passive: false,
		});
		document.addEventListener("touchmove", preventBackgroundTouch, {
			passive: false,
		});
		return () => {
			document.removeEventListener("wheel", preventBackgroundWheel);
			document.removeEventListener("touchmove", preventBackgroundTouch);
		};
	}, [backgroundScrollLocked]);

	useEffect(() => {
		const handleShortcut = (event: KeyboardEvent) => {
			if (event.key === "Escape" && open) {
				event.preventDefault();
				closeSearch();
				return;
			}

			if (
				!open &&
				shortcut &&
				event.key.toLowerCase() === shortcut.toLowerCase() &&
				!event.repeat &&
				!event.metaKey &&
				!event.ctrlKey &&
				!event.altKey &&
				!event.shiftKey &&
				!isEditableTarget(event.target)
			) {
				event.preventDefault();
				openSearch();
			}
		};

		window.addEventListener("keydown", handleShortcut);
		return () => window.removeEventListener("keydown", handleShortcut);
	}, [closeSearch, open, openSearch, shortcut]);

	// Only this component's own state. Telling the consumer the query changed is
	// a side effect, so it waits for the effect below.
	useOnOpen(open, () => {
		setQuery("");
		moveTo(null);
	});

	// Keyed to `open` alone. `onQueryChange` is read through a ref because an
	// inline one changes identity on every keystroke, and this effect clearing
	// the field on every keystroke is exactly what that costs. Written after
	// commit for the reason `lib/hooks/use-row-cursor.ts` gives at length.
	const notifyQuery = useRef(onQueryChange);
	useLayoutEffect(() => {
		notifyQuery.current = onQueryChange;
	});

	useEffect(() => {
		if (open) {
			notifyQuery.current?.("");
			const frame = requestAnimationFrame(() => inputRef.current?.focus());
			return () => cancelAnimationFrame(frame);
		}

		if (wasOpenRef.current) {
			const frame = requestAnimationFrame(() => {
				const previousFocus = previousFocusRef.current;
				const focusTarget = previousFocus?.isConnected
					? previousFocus
					: triggerRef.current;
				focusTarget?.focus();
			});
			return () => cancelAnimationFrame(frame);
		}
	}, [open]);

	useEffect(() => {
		wasOpenRef.current = open;
	}, [open]);

	useEffect(() => {
		if (!open) return;
		listRef.current
			?.querySelector<HTMLElement>(`[data-index="${activeIndex}"]`)
			?.scrollIntoView({ block: "nearest" });
	}, [activeIndex, open]);
	useEffect(() => {
		if (activeItem?.id !== undefined) previewRef.current?.scrollTo({ top: 0 });
	}, [activeItem?.id]);

	const selectItem = useCallback(
		(item: MorphingSearchItem) => {
			item.onSelect?.();
			onSelect?.(item);
			closeSearch();
		},
		[closeSearch, onSelect],
	);

	const handleDialogKeyDown = (event: ReactKeyboardEvent<HTMLDivElement>) => {
		// Preview controls retain their own keyboard behavior (links, forms, etc.).
		const target = event.target;
		const navigatingResults =
			target === event.currentTarget ||
			target === inputRef.current ||
			(target instanceof HTMLElement &&
				target.getAttribute("role") === "option");
		if (event.nativeEvent.isComposing) return;
		if (navigatingResults && event.key === "ArrowDown") {
			event.preventDefault();
			moveActive(1);
			return;
		}

		if (navigatingResults && event.key === "ArrowUp") {
			event.preventDefault();
			moveActive(-1);
			return;
		}

		if (navigatingResults && event.key === "Enter") {
			event.preventDefault();
			const item = rows[activeIndex];
			if (item) selectItem(item);
			return;
		}

		if (event.key !== "Tab" || !dialogRef.current) return;
		const focusable = Array.from(
			dialogRef.current.querySelectorAll<HTMLElement>(
				'a[href], input:not([disabled]), textarea:not([disabled]), select:not([disabled]), button:not([disabled]), [tabindex]:not([tabindex="-1"])',
			),
		);
		const first = focusable[0];
		const last = focusable.at(-1);
		if (!first || !last) return;

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

	const shellLayoutId = `${uid}-shell`;
	const listboxId = `${uid}-results`;
	const viewportWidth = mounted ? window.innerWidth : 1024;
	const viewportHeight = mounted ? window.innerHeight : 768;
	const panelWidth = Math.min(
		Math.max(anchorRect.width, hasPreviews ? 720 : 448),
		Math.max(0, viewportWidth - 32),
	);
	const panelLeft = Math.max(
		16,
		Math.min(anchorRect.left, viewportWidth - panelWidth - 16),
	);
	const resultsHeight = Math.max(
		0,
		Math.min(hasPreviews ? 360 : 288, viewportHeight - 80),
	);
	const panelTop = Math.max(
		16,
		Math.min(anchorRect.top, viewportHeight - resultsHeight - 64),
	);
	const stackedPreview = hasPreviews && panelWidth < 600;
	const collapsedContentClip = `inset(${Math.max(0, anchorRect.top - panelTop)}px ${Math.max(
		0,
		panelLeft + panelWidth - anchorRect.left - anchorRect.width,
	)}px ${Math.max(0, panelTop + resultsHeight - anchorRect.top)}px ${Math.max(0, anchorRect.left - panelLeft)}px round 12px)`;
	const expandedContentClip = "inset(0px 0px 0px 0px round 12px)";

	// Neither grouping layer carries a box: they only hold `inert`/`aria-hidden`,
	// the z-index and the presence key, and every child below is `fixed` and
	// resolves against the viewport itself. The click catcher spans the viewport
	// edges but has no children and filters nothing, so it is not a sampling
	// layer either. See tests/fixed-overlay-edge-sampling.test.tsx.
	const overlay = mounted
		? createPortal(
				<div
					aria-hidden={!open}
					inert={!open}
					className="pointer-events-none fixed left-0 top-0 z-50 size-0"
				>
					<AnimatePresence
						initial={false}
						mode="popLayout"
						onExitComplete={() => setBackgroundScrollLocked(false)}
					>
						{open ? (
							<motion.div
								key="morphing-search-overlay"
								className="fixed left-0 top-0 size-0"
							>
								<button
									type="button"
									aria-label="Close search"
									className="pointer-events-auto fixed inset-0 cursor-default bg-transparent"
									onClick={closeSearch}
								/>

								<motion.div
									layoutId={shellLayoutId}
									aria-hidden="true"
									className="fixed z-10 rounded-xl bg-background/90 backdrop-blur-xl"
									style={{
										top: panelTop,
										left: panelLeft,
										width: panelWidth,
										height: 48 + resultsHeight,
										boxShadow: "inset 0 0 0 1px var(--color-border)",
									}}
									transition={morphTransition}
								/>

								<motion.div
									ref={dialogRef}
									role="dialog"
									aria-modal="true"
									aria-label="Search"
									onKeyDown={handleDialogKeyDown}
									initial={
										reduce
											? false
											: { opacity: 0, clipPath: collapsedContentClip }
									}
									animate={{ opacity: 1, clipPath: expandedContentClip }}
									exit={{
										opacity: 0,
										clipPath: collapsedContentClip,
										transition: reduce
											? { duration: 0 }
											: {
													clipPath: SEARCH_CLIP_TRANSITION,
													opacity: SEARCH_MORPH,
												},
									}}
									transition={
										reduce
											? { duration: 0 }
											: {
													clipPath: SEARCH_CLIP_TRANSITION,
													opacity: SEARCH_MORPH,
												}
									}
									className="pointer-events-auto fixed z-20 overflow-hidden rounded-xl"
									style={{
										top: panelTop,
										left: panelLeft,
										width: panelWidth,
									}}
								>
									<div
										className={cn(
											"flex h-12 items-center gap-2.5 border-b border-border",
											iconOnly ? "px-4" : "px-3.5",
										)}
									>
										<span className="shrink-0">
											<Search className="size-4 text-muted-foreground" />
										</span>
										<div className="flex h-10 min-w-0 flex-1 items-center">
											<input
												ref={inputRef}
												value={query}
												onChange={(event) => updateQuery(event.target.value)}
												role="combobox"
												aria-label={placeholder}
												aria-expanded="true"
												aria-controls={listboxId}
												aria-autocomplete="list"
												aria-activedescendant={
													rows.length > 0
														? `${uid}-option-${activeIndex}`
														: undefined
												}
												placeholder={placeholder}
												className="size-full bg-transparent text-sm text-foreground outline-none placeholder:text-muted-foreground"
											/>
										</div>
										{query ? (
											<button
												type="button"
												aria-label="Clear search"
												onClick={() => {
													updateQuery("");
													inputRef.current?.focus();
												}}
												className="flex size-7 shrink-0 items-center justify-center rounded-md text-muted-foreground transition-colors hover:bg-muted hover:text-foreground focus-visible:outline-2 focus-visible:outline-ring"
											>
												<X aria-hidden className="size-3.5" />
											</button>
										) : null}
										<kbd className="flex h-7 shrink-0 items-center rounded-md border border-border px-2 text-xs text-muted-foreground">
											Esc
										</kbd>
									</div>

									<div
										className={cn("flex min-h-0", stackedPreview && "flex-col")}
										style={hasPreviews ? { height: resultsHeight } : undefined}
									>
										<motion.div
											ref={listRef}
											id={listboxId}
											role="listbox"
											aria-label="Search results"
											transition={reduce ? { duration: 0 } : undefined}
											variants={
												reduce
													? undefined
													: {
															closed: {
																opacity: 0,
																transform: "translateY(6px)",
																transition: {
																	duration: 0.16,
																	delay: 0.18,
																	ease: EASE_OUT,
																},
															},
															open: {
																opacity: 1,
																transform: "translateY(0px)",
																transition: {
																	duration: 0.16,
																	ease: EASE_OUT,
																},
															},
														}
											}
											initial={
												reduce
													? { opacity: 1, transform: "translateY(0px)" }
													: "closed"
											}
											animate={
												reduce
													? { opacity: 1, transform: "translateY(0px)" }
													: "open"
											}
											exit={reduce ? undefined : "closed"}
											className="min-h-0 min-w-0 flex-1 overscroll-contain overflow-y-auto p-2"
											style={{
												maxHeight: resultsHeight,
											}}
										>
											{rows.length > 0 ? (
												grouped.map(({ label, entries, startIndex }) => (
													<fieldset
														key={label}
														className="m-0 min-w-0 border-0 p-0"
														aria-label={label || "Results"}
													>
														{hasGroups ? (
															<div
																aria-hidden
																className="px-3 pb-1 pt-3 text-[10px] font-semibold uppercase tracking-wider text-muted-foreground"
															>
																{label || "Results"}
															</div>
														) : null}
														{entries.map((item, offset) => {
															const index = startIndex + offset;
															const Icon = item.icon;
															const active = index === activeIndex;
															return (
																<button
																	key={item.id}
																	id={`${uid}-option-${index}`}
																	type="button"
																	role="option"
																	aria-selected={active}
																	data-index={index}
																	onPointerEnter={(event) => {
																		if (event.pointerType !== "touch")
																			moveTo(item.id);
																	}}
																	onPointerMove={(event) => {
																		if (event.pointerType !== "touch")
																			moveTo(item.id);
																	}}
																	onFocus={() => moveTo(item.id)}
																	onClick={() => selectItem(item)}
																	className="relative flex w-full items-center gap-2.5 rounded-lg px-3 py-2.5 text-left outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-inset"
																>
																	{active ? (
																		<motion.span
																			layoutId={`${uid}-active-result`}
																			className="absolute inset-0 rounded-lg bg-foreground/5"
																			transition={transition}
																		/>
																	) : null}
																	{Icon ? (
																		<Icon className="relative size-4 shrink-0 text-muted-foreground" />
																	) : null}
																	<span className="relative min-w-0">
																		<span className="block truncate text-sm font-medium text-foreground">
																			{item.title}
																		</span>
																		{item.description ? (
																			<span className="block truncate text-xs text-muted-foreground">
																				{item.description}
																			</span>
																		) : null}
																	</span>
																</button>
															);
														})}
													</fieldset>
												))
											) : (
												<p className="px-3 py-8 text-center text-sm text-muted-foreground">
													{emptyMessage}
												</p>
											)}
										</motion.div>
										{hasPreviews ? (
											<section
												ref={previewRef}
												aria-label="Result details"
												className={cn(
													"min-h-0 min-w-0 shrink-0 overflow-y-auto overscroll-contain border-border bg-muted/20 p-4 outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring",
													stackedPreview
														? "h-2/5 border-t"
														: "w-[44%] border-l",
												)}
											>
												<motion.div
													key={activeItem?.id ?? "empty"}
													initial={{ opacity: 0, y: reduce ? 0 : 4 }}
													animate={{ opacity: 1, y: 0 }}
													transition={{ duration: 0.14, ease: EASE_OUT }}
													className="space-y-3 break-words"
												>
													{activeItem ? (
														<>
															<h3 className="text-sm font-medium text-foreground">
																{activeItem.title}
															</h3>
															{activeItem.preview ?? (
																<p className="text-xs text-muted-foreground">
																	No details available.
																</p>
															)}
														</>
													) : (
														<p className="text-xs text-muted-foreground">
															Select a result to preview.
														</p>
													)}
												</motion.div>
											</section>
										) : null}
									</div>
								</motion.div>
							</motion.div>
						) : null}
					</AnimatePresence>
				</div>,
				document.body,
			)
		: null;

	return (
		<LayoutGroup id={uid}>
			<div
				ref={anchorRef}
				className={cn(
					"relative",
					iconOnly ? "size-12" : "h-12 w-72 max-w-full",
					className,
				)}
			>
				{!open ? (
					<motion.button
						ref={triggerRef}
						key="morphing-search-trigger"
						layoutId={shellLayoutId}
						type="button"
						aria-haspopup="dialog"
						aria-expanded="false"
						aria-label={placeholder}
						onClick={openSearch}
						transition={morphTransition}
						style={{
							boxShadow: "inset 0 0 0 1px var(--search-trigger-stroke)",
						}}
						className={cn(
							"flex size-full items-center rounded-xl bg-background/60 text-left backdrop-blur-md outline-none [--search-trigger-stroke:var(--color-border)] hover:[--search-trigger-stroke:var(--color-border-strong)] focus-visible:ring-2 focus-visible:ring-ring",
							iconOnly ? "cursor-pointer justify-center" : "cursor-text px-3.5",
						)}
					></motion.button>
				) : null}
				<motion.div
					aria-hidden="true"
					initial={false}
					animate={{ opacity: open ? 0 : 1 }}
					transition={
						reduce
							? { duration: 0 }
							: {
									duration: 0.1,
									delay: open ? 0.1 : 0.12,
									ease: EASE_OUT,
								}
					}
					className={cn(
						"pointer-events-none absolute inset-0 flex items-center",
						backgroundScrollLocked && "z-[60]",
						iconOnly ? "justify-center" : "gap-2.5 px-3.5",
					)}
				>
					<Search className="size-4 shrink-0 text-muted-foreground" />
					{iconOnly ? null : (
						<>
							<span className="min-w-0 flex-1 truncate text-sm text-muted-foreground">
								{placeholder}
							</span>
							{shortcut ? (
								<kbd className="flex h-7 min-w-7 shrink-0 items-center justify-center rounded-md border border-border px-2 text-xs text-muted-foreground">
									{shortcut.toUpperCase()}
								</kbd>
							) : null}
						</>
					)}
				</motion.div>
			</div>
			{overlay}
		</LayoutGroup>
	);
}