"use client";

import { useState, useEffect, useRef, useMemo, useCallback } from "react";
import { createPortal } from "react-dom";
import { useRouter, usePathname } from "next/navigation";
import {
	Search,
	X,
	CornerDownLeft,
	ArrowUp,
	ArrowDown,
	FileText,
	Cpu,
	Terminal,
	BookOpen,
	AlertTriangle,
	Box,
	Sparkles,
	Plug,
} from "lucide-react";
import { preparar, buscar, EXEMPLOS_DE_BUSCA } from "@/lib/searchEngine";
import { normalizar } from "@/lib/searchTopics";

const TIPOS_PT = {
	resposta: { label: "Resposta", Icon: Sparkles, cor: "bg-accent text-accent-contrast" },
	pino: { label: "Pinos", Icon: Plug, cor: "bg-accent text-accent-contrast" },
	pagina: { label: "Página", Icon: FileText, cor: "bg-surface-2 text-ink-soft" },
	serie: { label: "Série", Icon: Cpu, cor: "bg-accent-soft text-accent" },
	framework: { label: "Framework", Icon: Terminal, cor: "bg-teal-soft text-teal" },
	glossario: { label: "Glossário", Icon: BookOpen, cor: "bg-copper-soft text-copper" },
	erro: { label: "Erro", Icon: AlertTriangle, cor: "bg-gold-soft text-gold" },
	componente: { label: "Componente", Icon: Box, cor: "bg-surface-2 text-ink-soft" },
};

const TIPOS_EN = {
	resposta: { label: "Answer", Icon: Sparkles, cor: "bg-accent text-accent-contrast" },
	pino: { label: "Pins", Icon: Plug, cor: "bg-accent text-accent-contrast" },
	pagina: { label: "Page", Icon: FileText, cor: "bg-surface-2 text-ink-soft" },
	serie: { label: "Series", Icon: Cpu, cor: "bg-accent-soft text-accent" },
	framework: { label: "Framework", Icon: Terminal, cor: "bg-teal-soft text-teal" },
	glossario: { label: "Glossary", Icon: BookOpen, cor: "bg-copper-soft text-copper" },
	erro: { label: "Error", Icon: AlertTriangle, cor: "bg-gold-soft text-gold" },
	componente: { label: "Component", Icon: Box, cor: "bg-surface-2 text-ink-soft" },
};

const INTELIGENTES = new Set(["resposta", "pino"]);

const EXEMPLOS_EN = ["flash s3", "usb pins c6", "gpio0 esp32", "brownout", "LVGL", "FreeRTOS"];

function Destaque({ texto, termos }) {
	if (!termos.length) return texto;
	const norm = normalizar(texto);
	if (norm.length !== texto.length) return texto;
	const marcas = new Array(texto.length).fill(false);
	for (const t of termos) {
		let i = norm.indexOf(t);
		while (i !== -1) {
			for (let k = i; k < i + t.length; k++) marcas[k] = true;
			i = norm.indexOf(t, i + t.length);
		}
	}
	const partes = [];
	let atual = "";
	let marcado = false;
	for (let i = 0; i < texto.length; i++) {
		if (marcas[i] !== marcado && atual) {
			partes.push({ t: atual, m: marcado });
			atual = "";
		}
		marcado = marcas[i];
		atual += texto[i];
	}
	if (atual) partes.push({ t: atual, m: marcado });
	return partes.map((p, i) =>
		p.m ? (
			<mark key={i} className="rounded-sm bg-accent-soft px-0.5 text-accent">
				{p.t}
			</mark>
		) : (
			<span key={i}>{p.t}</span>
		)
	);
}

function Pilula({ children, onClick, forte = false }) {
	const base = "rounded-full px-2.5 py-1 text-xs font-semibold";
	if (!onClick) return <span className={`${base} ${forte ? "bg-accent text-accent-contrast" : "bg-accent-soft text-accent"}`}>{children}</span>;
	return (
		<button
			type="button"
			onClick={onClick}
			className={`${base} cursor-pointer border border-line bg-surface text-ink-soft transition-colors hover:border-accent hover:text-accent`}
		>
			{children}
		</button>
	);
}

export default function SearchDialog() {
	const pathname = usePathname() || "";
	const locale = pathname === "/en" || pathname.startsWith("/en/") ? "en" : "pt";
	const isEn = locale === "en";

	const TIPOS = isEn ? TIPOS_EN : TIPOS_PT;
	const EXEMPLOS = isEn ? EXEMPLOS_EN : EXEMPLOS_DE_BUSCA;

	const [aberto, setAberto] = useState(false);
	const [montado, setMontado] = useState(false);
	const [consulta, setConsulta] = useState("");
	const [indice, setIndice] = useState(null);
	const [erro, setErro] = useState(false);
	const [ativo, setAtivo] = useState(0);
	const inputRef = useRef(null);
	const listaRef = useRef(null);
	const router = useRouter();

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

	const fechar = useCallback(() => {
		setAberto(false);
		setConsulta("");
		setAtivo(0);
	}, []);

	// Atalhos globais: Ctrl/⌘+K abre; "/" abre fora de campos de texto.
	useEffect(() => {
		function onKey(e) {
			const emCampo = /^(INPUT|TEXTAREA|SELECT)$/.test(e.target?.tagName) || e.target?.isContentEditable;
			if ((e.ctrlKey || e.metaKey) && e.key.toLowerCase() === "k") {
				e.preventDefault();
				setAberto((v) => !v);
			} else if (e.key === "/" && !emCampo && !e.ctrlKey && !e.metaKey && !e.altKey) {
				e.preventDefault();
				setAberto(true);
			} else if (e.key === "Escape") {
				fechar();
			}
		}
		document.addEventListener("keydown", onKey);
		return () => document.removeEventListener("keydown", onKey);
	}, [fechar]);

	const carregarIndice = useCallback(() => {
		setErro(false);
		let cancelado = false;
		const url = isEn ? "/api/busca/en?v=2" : "/api/busca?v=2";
		fetch(url, { cache: "no-cache" })
			.then((r) => {
				if (!r.ok) {
					// Fallback para /api/busca caso a rota dinâmica do locale falhe
					return fetch("/api/busca?v=2", { cache: "no-cache" }).then((r2) => {
						if (!r2.ok) throw new Error(`HTTP ${r2.status}`);
						return r2.json();
					});
				}
				return r.json();
			})
			.then((dados) => {
				if (!cancelado) {
					setIndice(preparar(dados));
				}
			})
			.catch((err) => {
				console.error("Erro ao carregar índice de busca:", err);
				if (!cancelado) setErro(true);
			});
		return () => {
			cancelado = true;
		};
	}, [isEn]);

	// Carrega o índice (textos + especificações + pinos) na primeira abertura.
	useEffect(() => {
		if (!aberto || indice) return;
		return carregarIndice();
	}, [aberto, indice, carregarIndice]);

	useEffect(() => {
		if (aberto) {
			document.body.style.overflow = "hidden";
			inputRef.current?.focus();
		}
		return () => {
			document.body.style.overflow = "";
		};
	}, [aberto]);

	const termos = useMemo(() => normalizar(consulta).split(/\s+/).filter((t) => t.length > 1), [consulta]);

	const busca = useMemo(() => {
		if (!indice) return { resultados: [], interpretacao: { chips: [], topicos: [] }, sugestoes: [], totalRespostas: 0 };
		if (!consulta.trim()) {
			return { resultados: indice.itens.filter((i) => i.tipo === "pagina"), interpretacao: { chips: [], topicos: [] }, sugestoes: [], totalRespostas: 0 };
		}
		return buscar(indice, consulta);
	}, [indice, consulta]);

	const { resultados, interpretacao, sugestoes } = busca;
	const vazia = !consulta.trim();

	useEffect(() => setAtivo(0), [consulta]);

	useEffect(() => {
		listaRef.current?.querySelector(`[data-idx="${ativo}"]`)?.scrollIntoView({ block: "nearest" });
	}, [ativo]);

	function ir(item) {
		if (!item) return;
		fechar();
		router.push(item.href);
		if (item.href.includes("#")) setTimeout(() => window.dispatchEvent(new HashChangeEvent("hashchange")), 80);
	}

	function anexar(termo) {
		setConsulta((c) => `${c.trim()} ${termo}`.trim());
		inputRef.current?.focus();
	}

	function onInputKey(e) {
		if (e.key === "ArrowDown") {
			e.preventDefault();
			setAtivo((i) => Math.min(i + 1, resultados.length - 1));
		} else if (e.key === "ArrowUp") {
			e.preventDefault();
			setAtivo((i) => Math.max(i - 1, 0));
		} else if (e.key === "Enter") {
			e.preventDefault();
			ir(resultados[ativo]);
		}
	}

	const entendeu = interpretacao.chips.length > 0 || interpretacao.topicos.length > 0;

	return (
		<>
			<button
				type="button"
				id="botao-busca"
				onClick={() => setAberto(true)}
				className="flex h-11 min-w-11 shrink-0 cursor-pointer items-center justify-center gap-2 rounded-full border border-line px-3 text-ink transition-colors hover:bg-surface-2 xl:px-4"
				aria-label={isEn ? "Search ESPDocs (Ctrl+K)" : "Buscar no ESPDocs (Ctrl+K)"}
			>
				<Search className="h-4 w-4" aria-hidden="true" />
				<span className="hidden text-sm font-medium xl:inline">{isEn ? "Search" : "Buscar"}</span>
				<kbd className="hidden rounded-md border border-line bg-surface-2 px-1.5 py-0.5 font-mono text-xs font-semibold text-muted xl:inline">Ctrl K</kbd>
			</button>

			{montado &&
				aberto &&
				createPortal(
					<div className="fixed inset-0 z-[120] flex items-start justify-center px-4 pt-[8vh]" role="dialog" aria-modal="true" aria-label={isEn ? "Search ESPDocs" : "Buscar no ESPDocs"}>
						<div className="dialog-scrim absolute inset-0 bg-black/45 backdrop-blur-sm" onClick={fechar} />
						<div className="dialog-panel relative flex max-h-[80vh] w-full max-w-2xl flex-col overflow-hidden rounded-3xl border border-line bg-canvas shadow-2xl">
							<div className="flex items-center gap-3 border-b border-line px-5">
								<Search className="h-5 w-5 shrink-0 text-accent" aria-hidden="true" />
								<input
									ref={inputRef}
									id="campo-busca"
									type="text"
									value={consulta}
									onChange={(e) => setConsulta(e.target.value)}
									onKeyDown={onInputKey}
									placeholder={isEn ? "Ask ESPDocs: “flash s3”, “usb pins c6”, “gpio0 esp32”…" : "Pergunte ao ESPDocs: “flash s3”, “pinos usb c6”, “gpio0 esp32”…"}
									className="flex-1 bg-transparent py-5 text-base text-ink outline-none placeholder:text-muted"
									autoComplete="off"
									spellCheck={false}
									aria-label={isEn ? "Search query" : "Termo de busca"}
								/>
								<button
									type="button"
									onClick={fechar}
									className="grid h-9 w-9 cursor-pointer place-items-center rounded-full text-muted transition-colors hover:bg-surface-2 hover:text-ink"
									aria-label={isEn ? "Close search" : "Fechar busca"}
								>
									<X className="h-4 w-4" />
								</button>
							</div>

							{entendeu && (
								<div className="flex flex-wrap items-center gap-2 border-b border-line bg-surface px-5 py-2.5">
									<span className="text-xs font-semibold text-muted">{isEn ? "Understood:" : "Entendi:"}</span>
									{interpretacao.chips.map((c) => (
										<Pilula key={c.chave} forte>{c.nome}</Pilula>
									))}
									{interpretacao.topicos.map((t) => (
										<Pilula key={t.id}>{t.nome}</Pilula>
									))}
								</div>
							)}

							{sugestoes.length > 0 && (
								<div className="flex flex-wrap items-center gap-2 border-b border-line px-5 py-2.5">
									<span className="text-xs font-semibold text-muted">{interpretacao.chips.length ? (isEn ? "Ask about:" : "Perguntar sobre:") : (isEn ? "Which chip?" : "Para qual chip?")}</span>
									{sugestoes.map((s) => (
										<Pilula key={s.rotulo} onClick={() => anexar(s.anexar)}>
											{s.rotulo}
										</Pilula>
									))}
								</div>
							)}

							<div ref={listaRef} className="flex-1 overflow-y-auto p-2" role="listbox">
								{erro && (
									<div className="p-6 text-center">
										<p className="text-sm font-semibold text-danger">{isEn ? "Could not load search index." : "Não foi possível carregar o índice de busca."}</p>
										<button
											type="button"
											onClick={carregarIndice}
											className="btn btn-primary btn-sm mt-3"
										>
											{isEn ? "Try again" : "Tentar novamente"}
										</button>
									</div>
								)}
								{!erro && !indice && <p className="p-6 text-center text-sm text-muted">{isEn ? "Loading…" : "Carregando…"}</p>}

								{indice && vazia && (
									<div className="px-3 pb-3 pt-1">
										<p className="text-xs font-semibold text-muted">{isEn ? "Try asking" : "Experimente perguntar"}</p>
										<div className="mt-2 flex flex-wrap gap-2">
											{EXEMPLOS.map((ex) => (
												<Pilula key={ex} onClick={() => setConsulta(ex)}>
													{ex}
												</Pilula>
											))}
										</div>
										<p className="mt-4 text-xs font-semibold text-muted">{isEn ? "Go to" : "Ir para"}</p>
									</div>
								)}

								{indice && !vazia && resultados.length === 0 && (
									<div className="p-8 text-center">
										<p className="font-display text-lg font-semibold text-ink">{isEn ? `No results for “${consulta}”` : `Nenhum resultado para “${consulta}”`}</p>
										<p className="mt-1 text-sm text-muted">{isEn ? "Try “brownout”, “flash s3”, “usb pins c6” or “LVGL”." : "Tente “brownout”, “flash s3”, “pinos usb c6” ou “LVGL”."}</p>
									</div>
								)}

								{resultados.map((item, idx) => {
									const { Icon, label, cor } = TIPOS[item.tipo] ?? TIPOS.pagina;
									const sel = idx === ativo;
									const inteligente = INTELIGENTES.has(item.tipo);
									return (
										<button
											key={`${item.id}-${idx}`}
											type="button"
											role="option"
											aria-selected={sel}
											data-idx={idx}
											onMouseMove={() => setAtivo(idx)}
											onClick={() => ir(item)}
											className={`flex w-full cursor-pointer items-start gap-3 rounded-2xl p-3 text-left transition-colors ${
												sel ? "bg-surface-2" : ""
											} ${inteligente ? "my-1 border border-line" : ""}`}
										>
											<div className={`grid h-9 w-9 shrink-0 place-items-center rounded-xl ${cor}`}>
												<Icon className="h-4 w-4" aria-hidden="true" />
											</div>
											<div className="min-w-0 flex-1">
												<div className="flex items-center gap-2">
													<span className="truncate text-sm font-semibold text-ink">
														{inteligente ? item.titulo : <Destaque texto={item.titulo} termos={termos} />}
													</span>
													<span className={`shrink-0 rounded-full px-2 py-0.5 text-xs font-semibold ${inteligente ? "bg-accent-soft text-accent" : cor}`}>{label}</span>
												</div>
												<p className="mt-0.5 line-clamp-2 text-xs leading-relaxed text-muted">
													{inteligente ? item.descricao : <Destaque texto={item.descricao} termos={termos} />}
												</p>

												{item.linhas && (
													<dl className="mt-2 grid gap-x-4 gap-y-1 text-xs sm:grid-cols-[auto_1fr]">
														{item.linhas.map((l) => (
															<div key={l.k} className="contents">
																<dt className="font-semibold text-ink-soft">{l.k}</dt>
																<dd className="text-ink">{l.v}</dd>
															</div>
														))}
													</dl>
												)}

												{item.chips && (
													<div className="mt-2 flex flex-wrap gap-1.5">
														{item.chips.map((c) => (
															<span key={c} className="rounded-md border border-line bg-surface px-1.5 py-0.5 font-mono text-xs text-ink-soft">
																{c}
															</span>
														))}
													</div>
												)}
											</div>
											{sel && <CornerDownLeft className="mt-2 h-4 w-4 shrink-0 text-accent" aria-hidden="true" />}
										</button>
									);
								})}
							</div>

							<div className="hidden items-center gap-4 border-t border-line bg-surface px-4 py-2.5 text-xs text-muted md:flex">
								<span className="flex items-center gap-1"><ArrowUp className="h-3 w-3" /><ArrowDown className="h-3 w-3" /> {isEn ? "navigate" : "navegar"}</span>
								<span className="flex items-center gap-1"><CornerDownLeft className="h-3 w-3" /> {isEn ? "open" : "abrir"}</span>
								<span><kbd className="font-mono font-semibold">Esc</kbd> {isEn ? "close" : "fechar"}</span>
								<span className="ml-auto">{vazia ? (isEn ? "Tip: press / on any page" : "Dica: pressione / em qualquer página") : `${resultados.length} ${isEn ? "result(s)" : "resultado(s)"}`}</span>
							</div>
						</div>
					</div>,
					document.body
				)}
		</>
	);
}