"use client";

import Link from "next/link";
import { usePathname, useRouter } from "next/navigation";
import { FormEvent, useEffect, useMemo, useRef, useState } from "react";

import AccountMenu from "@/components/AccountMenu";
import { products, site } from "@/data/site";
import { localeOptions, showsCatalog } from "@/i18n/config";
import { useLocale, useMessages, useSetLocale } from "@/i18n/locale-context";

function SearchIcon() {
  return (
    <svg width="15" height="15" viewBox="0 0 24 24" fill="none" aria-hidden>
      <circle cx="11" cy="11" r="6.25" stroke="currentColor" strokeWidth="1.75" />
      <path d="M16 16.5 20 20.5" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" />
    </svg>
  );
}

function ChevronIcon() {
  return (
    <svg className="nav-caret" width="10" height="10" viewBox="0 0 12 12" fill="none" aria-hidden>
      <path d="M2.5 4.5 6 8l3.5-3.5" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" />
    </svg>
  );
}

export default function Header() {
  const pathname = usePathname();
  const router = useRouter();
  const locale = useLocale();
  const t = useMessages();
  const setLocale = useSetLocale();
  const catalog = showsCatalog(locale);
  const [open, setOpen] = useState(false);
  const [query, setQuery] = useState("");
  const [searchOpen, setSearchOpen] = useState(false);
  const [productsOpen, setProductsOpen] = useState(false);
  const [hash, setHash] = useState("");
  const searchRef = useRef<HTMLDivElement>(null);
  const inputRef = useRef<HTMLInputElement>(null);

  useEffect(() => {
    function onPointer(event: MouseEvent) {
      if (!searchRef.current?.contains(event.target as Node)) setSearchOpen(false);
    }
    function onKey(event: KeyboardEvent) {
      if (event.key === "Escape") setSearchOpen(false);
    }
    document.addEventListener("mousedown", onPointer);
    document.addEventListener("keydown", onKey);
    return () => {
      document.removeEventListener("mousedown", onPointer);
      document.removeEventListener("keydown", onKey);
    };
  }, []);

  useEffect(() => {
    if (searchOpen) inputRef.current?.focus();
  }, [searchOpen]);

  useEffect(() => {
    function syncHash() {
      setHash(window.location.hash);
    }
    syncHash();
    window.addEventListener("hashchange", syncHash);
    return () => window.removeEventListener("hashchange", syncHash);
  }, [pathname]);

  const results = useMemo(() => {
    const q = query.trim().toLowerCase();
    if (q.length < 2) return [];
    const pages = [
      { href: "/", title: t.nav.home },
      ...(catalog
        ? [
            { href: "/products", title: t.nav.products },
            { href: "/blog", title: t.nav.blog },
          ]
        : []),
      { href: "/about", title: t.nav.about },
      { href: "/contact", title: t.nav.contact },
    ];
    const catalogItems = catalog
      ? t.categories.map((product) => ({
          href: `/#product-${product.id}`,
          title: product.title,
        }))
      : [];
    return [...pages, ...catalogItems].filter((item) => item.title.toLowerCase().includes(q)).slice(0, 8);
  }, [catalog, query, t]);

  function onSearch(event: FormEvent) {
    event.preventDefault();
    const first = results[0];
    if (!first) return;
    router.push(first.href);
    setSearchOpen(false);
    setQuery("");
  }

  return (
    <header className="site-header">
      <div className="container header-inner">
        <div className="header-start">
          <Link href="/" className="brand" onClick={() => setOpen(false)}>
            {/* eslint-disable-next-line @next/next/no-img-element */}
            <img src={site.logo} alt={t.brand.shortName} width={32} height={32} />
            <span className="brand-text">
              <strong>{t.brand.shortName}</strong>
              {locale !== "en" ? <span className="en">{t.brand.nameEnShort}</span> : null}
            </span>
          </Link>

          <button
            type="button"
            className="menu-toggle"
            aria-expanded={open}
            aria-label={t.nav.menu}
            onClick={() => setOpen((value) => !value)}
          >
            {t.nav.menu}
          </button>

          <nav className={open ? "nav open" : "nav"}>
            <Link
              href="/"
              className={pathname === "/" && !hash.startsWith("#product") && hash !== "#products" ? "active" : undefined}
              onClick={() => setOpen(false)}
            >
              {t.nav.home}
            </Link>

            {catalog ? (
              <div
                className={productsOpen ? "nav-dropdown open" : "nav-dropdown"}
                onMouseEnter={() => setProductsOpen(true)}
                onMouseLeave={() => setProductsOpen(false)}
              >
                <Link
                  href="/products"
                  className={pathname.startsWith("/products") || hash === "#products" || hash.startsWith("#product-") ? "active" : undefined}
                  onClick={() => setOpen(false)}
                >
                  {t.nav.products}
                  <ChevronIcon />
                </Link>
                <ul className="nav-sub">
                  {products.map((product) => {
                    const copy = t.categories.find((item) => item.id === product.id);
                    return (
                      <li key={product.id}>
                        <Link href={`/#product-${product.id}`} onClick={() => setOpen(false)}>
                          {copy?.title || product.title}
                        </Link>
                      </li>
                    );
                  })}
                </ul>
              </div>
            ) : null}

            {catalog ? (
              <Link
                href="/blog"
                className={pathname.startsWith("/blog") ? "active" : undefined}
                onClick={() => setOpen(false)}
              >
                {t.nav.blog}
              </Link>
            ) : null}

            <Link href="/about" className={pathname === "/about" ? "active" : undefined} onClick={() => setOpen(false)}>
              {t.nav.about}
            </Link>
            <Link href="/contact" className={pathname === "/contact" ? "active" : undefined} onClick={() => setOpen(false)}>
              {t.nav.contact}
            </Link>
          </nav>
        </div>

        <div className="header-tools">
          <div className={searchOpen ? "header-search open" : "header-search"} ref={searchRef}>
            <form onSubmit={onSearch}>
              <label className="sr-only" htmlFor="site-search">
                {t.nav.search}
              </label>
              <input
                id="site-search"
                ref={inputRef}
                value={query}
                tabIndex={searchOpen ? 0 : -1}
                onChange={(event) => {
                  setQuery(event.target.value);
                  setSearchOpen(true);
                }}
                onFocus={() => setSearchOpen(true)}
                placeholder={t.nav.search}
              />
              <button
                type={searchOpen && query.trim() ? "submit" : "button"}
                className="header-tool"
                aria-expanded={searchOpen}
                aria-label={t.nav.search}
                onClick={() => {
                  if (!searchOpen) setSearchOpen(true);
                }}
              >
                <SearchIcon />
              </button>
            </form>
            {searchOpen && results.length > 0 ? (
              <ul className="header-search-results">
                {results.map((item) => (
                  <li key={`${item.href}-${item.title}`}>
                    <Link
                      href={item.href}
                      onClick={() => {
                        setSearchOpen(false);
                        setQuery("");
                      }}
                    >
                      {item.title}
                    </Link>
                  </li>
                ))}
              </ul>
            ) : null}
          </div>

          <label className="header-lang">
            <span className="sr-only">{t.nav.language}</span>
            <select value={locale} onChange={(event) => setLocale(event.target.value)} aria-label={t.nav.languageSelect}>
              {localeOptions.map((option) => (
                <option key={option.id} value={option.id}>
                  {option.label}
                </option>
              ))}
            </select>
          </label>

          <AccountMenu />
        </div>
      </div>
    </header>
  );
}