"use client";

import Link from "next/link";
import { usePathname, useRouter } from "next/navigation";
import { useEffect, useMemo, useState } from "react";
import LoginModal from "@/components/LoginModal";
import { fetchAnonymousMenu, isMenuActive, type MenuItem } from "@/app/store/common";

// const REGISTER_HREF = "/reuse/apply/place";
const LS_TOKEN_KEY = "reuse_accessToken";
const LS_USER_KEY = "reuse_userName";

const DEFAULT_NAV_ITEMS: Pick<MenuItem, "menuCd" | "menuKornNm" | "urlPath" | "newWndwYn">[] = [
  { menuCd: 1, menuKornNm: "물 재이용 소개", urlPath: "/reuse/intro/law", newWndwYn: "N" },
  { menuCd: 2, menuKornNm: "물 재이용 현황", urlPath: "/reuse/cases/rain", newWndwYn: "N" },
  { menuCd: 3, menuKornNm: "물 재이용 사례", urlPath: "/reuse/business/rain/suwon", newWndwYn: "N" },
  { menuCd: 4, menuKornNm: "수요신청", urlPath: "/reuse/apply/place", newWndwYn: "N" },
];

export default function TopNav() {
  const router = useRouter();
  const pathname = usePathname();

  const [loginOpen, setLoginOpen] = useState(false);
  const [userName, setUserName] = useState<string | null>(null);
  const [topMenus, setTopMenus] = useState<MenuItem[]>([]);

  useEffect(() => {
    const name = localStorage.getItem(LS_USER_KEY);
    setUserName(name);
  }, []);

  useEffect(() => {
    let isMounted = true;

    (async () => {
      try {
        const loaded = await fetchAnonymousMenu();
        if (!isMounted) return;

        const level1 = loaded.filter((menu) => menu.levelNo === 1 || menu.parentId === null);
        setTopMenus(level1);
      } catch (error) {
        console.error("Failed to load DN top menu", error);
        if (!isMounted) return;
        setTopMenus([]);
      }
    })();

    return () => {
      isMounted = false;
    };
  }, []);

  const navItems = useMemo(() => {
    if (topMenus.length > 0) return topMenus;

    return DEFAULT_NAV_ITEMS.map((item) => ({
      ...item,
      parentId: null,
      sortSeq: 0,
      children: [],
      levelNo: 1,
      useYn: "Y",
      otptYn: "Y",
    }));
  }, [topMenus]);
  
  const openLogin = () => setLoginOpen(true);

  const logout = () => {
    localStorage.removeItem(LS_TOKEN_KEY);
    localStorage.removeItem(LS_USER_KEY);
    setUserName(null);
    router.refresh();
  };

  return (
    <>
      <header className="fixed left-0 right-0 top-0 z-50 border-b bg-white shadow-md backdrop-blur">
        {/* ✅ 좌/중/우 정렬이 되도록 컨테이너 구성 */}
        <div className="px-6">
          <div className="relative flex h-[83px] items-center justify-between">
            {/* 좌측: 로고 */}
            <div className="flex items-center gap-3">
              <Link href="/main" className="flex items-center">
                <img src="/images/landing/logo.png" alt="HASUON" className="h-9 w-auto" />
              </Link>
            </div>

            {/* 중앙: 상단 메뉴 */}
            <nav className="absolute left-1/2 flex -translate-x-1/2 items-center gap-[40px] text-sm font-medium">
              {navItems.map((item) => {
                const requiresLogin = (item.urlPath)? item.urlPath.startsWith("/apply") : false;
                const active = isMenuActive(pathname, item);
                const className = [
                  "relative px-3 py-2 text-lg font-bold",
                  active ? "text-sky-700" : "text-gray-800 hover:text-sky-700",
                ].join(" ");

                if (requiresLogin && !userName) {
                  return (
                    <button
                      key={item.menuCd}
                      type="button"
                      onClick={openLogin}
                      className={className}
                    >
                      {item.menuKornNm}
                    </button>
                  );
                }

                if (item.newWndwYn === "Y") {
                  return (
                    <button
                      key={item.menuCd}
                      type="button"
                      onClick={() => window.open(item.urlPath, "_blank")}
                      className={className}
                    >
                      {item.menuKornNm}
                    </button>
                  );
                }

                return (
                  <Link key={item.menuCd} href={item.urlPath || "#"} className={className}>
                    {item.menuKornNm}
                  </Link>
                );
              })}
            </nav>

            {/* ✅ 우측: 로그인 버튼 / 로그인 정보 + 로그아웃 */}
            <div className="flex items-center gap-3">
              {!userName ? (
                <button
                  type="button"
                  onClick={openLogin}
                  className="inline-flex items-center gap-2 rounded-md bg-sky-500 px-4 py-2 text-base text-white hover:bg-sky-600"
                >
                  로그인
                  <span aria-hidden>
                    <img
                      src="/images/landing/icon_login.png"
                      alt="login icon"
                      className="ml-1 h-6 w-6 object-contain"
                    />
                  </span>
                </button>
              ) : (
                <>
                  <span className="text-base text-gray-700">
                    <strong className="text-xl text-emerald-600">{userName}</strong>님 환영합니다.
                  </span>
                  <button
                    type="button"
                    onClick={logout}
                    className="inline-flex items-center gap-2 rounded-md bg-red-500 px-4 py-2 text-base text-white hover:bg-red-600"
                  >
                    로그아웃
                    <span aria-hidden>
                      <img
                        src="/images/landing/icon_logout.png"
                        alt="logout icon"
                        className="h-6 w-6 object-contain"
                      />
                    </span>
                  </button>
                </>
              )}
            </div>
          </div>
        </div>
      </header>

      <LoginModal
        open={loginOpen}
        onClose={() => setLoginOpen(false)}
        onSuccess={({ userName: nextUserName, accessToken }) => {
          localStorage.setItem(LS_USER_KEY, nextUserName);
          if (accessToken) localStorage.setItem(LS_TOKEN_KEY, accessToken);
          setUserName(nextUserName);
          setLoginOpen(false);
          router.refresh();
        }}
      />
    </>
  );
}