"use client";

import { useEffect, ReactNode } from "react";
import { useRouter } from "next/navigation";
import { useAuth } from "@/hooks/useAuth";
import { Loader2 } from "lucide-react";

interface AuthGuardProps {
  children: ReactNode;
  requireAuth?: boolean;
  requireAdmin?: boolean;
  redirectTo?: string;
  fallback?: ReactNode;
}

/**
 * 인증 보호 컴포넌트
 * 로그인 상태 및 권한에 따라 접근을 제어
 * - 토큰 갱신/401 처리는 client.ts 인터셉터가 담당
 * - 이 컴포넌트는 인증 상태 기반 라우팅 가드 역할만 수행
 */
export function AuthGuard({
  children,
  requireAuth = true,
  requireAdmin = false,
  redirectTo = "/login",
  fallback,
}: AuthGuardProps) {
  const { isLoggedIn, isAdmin, loading } = useAuth();
  const router = useRouter();

  useEffect(() => {
    if (loading) return;

    // 토큰이 있는데 아직 인증 확인 중이면 대기
    if (typeof window !== "undefined") {
      const token = localStorage.getItem("authToken");
      if (token && !isLoggedIn && !loading) {
        return;
      }
    }

    if (requireAuth && !isLoggedIn) {
      router.push(redirectTo);
      return;
    }

    if (requireAdmin && !isAdmin) {
      router.push(redirectTo);
      return;
    }
  }, [requireAuth, requireAdmin, loading, isLoggedIn, isAdmin, redirectTo, router]);

  if (loading) {
    return (
      fallback || (
        <div className="flex h-screen items-center justify-center">
          <div className="flex flex-col items-center gap-3">
            <Loader2 className="h-8 w-8 animate-spin text-primary" />
            <p className="text-sm text-muted-foreground">로딩 중...</p>
          </div>
        </div>
      )
    );
  }

  if (requireAuth && !isLoggedIn) {
    return (
      fallback || (
        <div className="flex h-screen items-center justify-center">
          <div className="flex flex-col items-center gap-3">
            <Loader2 className="h-8 w-8 animate-spin text-primary" />
            <p className="text-sm text-muted-foreground">인증 확인 중...</p>
          </div>
        </div>
      )
    );
  }

  if (requireAdmin && !isAdmin) {
    return (
      fallback || (
        <div className="flex h-screen items-center justify-center">
          <p className="text-sm text-muted-foreground">관리자 권한이 필요합니다.</p>
        </div>
      )
    );
  }

  return <>{children}</>;
}

/**
 * 로그인 여부만 확인하는 간단한 가드
 */
export function RequireAuth({ children }: { children: ReactNode }) {
  return <AuthGuard requireAuth={true}>{children}</AuthGuard>;
}

/**
 * 관리자 권한을 요구하는 가드
 */
export function RequireAdmin({ children }: { children: ReactNode }) {
  return (
    <AuthGuard requireAuth={true} requireAdmin={true}>
      {children}
    </AuthGuard>
  );
}

export default AuthGuard;