"use client";

import { useCallback, useEffect, useState } from "react";
import { api } from "@/lib/api";

// #329 — admin/page.tsx에서 추출
interface AdminUser {
  id: string;
  email: string | null;
  nickname: string | null;
  avatar_url: string | null;
  is_admin: boolean;
  provider: string | null;
  created_at: string | null;
  favorite_count: number;
  review_count: number;
  memo_count: number;
}

interface UserFavorite {
  id: string;
  name: string;
  address: string | null;
  region: string | null;
  cuisine_type: string | null;
  rating: number | null;
  business_status: string | null;
  created_at: string | null;
}

interface UserReview {
  id: string;
  restaurant_id: string;
  rating: number;
  review_text: string | null;
  visited_at: string | null;
  created_at: string | null;
  restaurant_name: string | null;
}

interface UserMemo {
  id: string;
  restaurant_id: string;
  rating: number | null;
  memo_text: string | null;
  visited_at: string | null;
  created_at: string;
  restaurant_name: string | null;
}

export function UsersPanel() {
  const [users, setUsers] = useState<AdminUser[]>([]);
  const [total, setTotal] = useState(0);
  const [page, setPage] = useState(0);
  const [selectedUser, setSelectedUser] = useState<AdminUser | null>(null);
  const [favorites, setFavorites] = useState<UserFavorite[]>([]);
  const [reviews, setReviews] = useState<UserReview[]>([]);
  const [memos, setMemos] = useState<UserMemo[]>([]);
  const [detailLoading, setDetailLoading] = useState(false);
  const perPage = 20;

  const loadUsers = useCallback(async (p: number) => {
    try {
      const res = await api.getAdminUsers({ limit: perPage, offset: p * perPage });
      setUsers(res.users);
      setTotal(res.total);
    } catch (e) {
      console.error("Failed to load users:", e);
    }
  }, []);

  useEffect(() => {
    loadUsers(page);
  }, [page, loadUsers]);

  const handleSelectUser = async (u: AdminUser) => {
    if (selectedUser?.id === u.id) {
      setSelectedUser(null);
      setFavorites([]);
      setReviews([]);
      setMemos([]);
      return;
    }
    setSelectedUser(u);
    setDetailLoading(true);
    try {
      const [favs, revs, mems] = await Promise.all([
        api.getAdminUserFavorites(u.id),
        api.getAdminUserReviews(u.id),
        api.getAdminUserMemos(u.id),
      ]);
      setFavorites(favs);
      setReviews(revs);
      setMemos(mems);
    } catch (e) {
      console.error(e);
    } finally {
      setDetailLoading(false);
    }
  };

  const totalPages = Math.ceil(total / perPage);

  return (
    <div className="space-y-4">
      <h2 className="text-lg font-bold">유저 관리 ({total}명)</h2>

      {/* Users Table */}
      <div className="bg-surface rounded-lg shadow overflow-hidden">
        <table className="w-full text-sm">
          <thead className="bg-brand-50 border-b border-brand-100 text-brand-800 text-sm font-semibold">
            <tr>
              <th className="text-left px-4 py-2">사용자</th>
              <th className="text-left px-4 py-2">이메일</th>
              <th className="text-center px-4 py-2">관리자</th>
              <th className="text-center px-4 py-2">찜</th>
              <th className="text-center px-4 py-2">리뷰</th>
              <th className="text-center px-4 py-2">메모</th>
              <th className="text-left px-4 py-2">가입일</th>
            </tr>
          </thead>
          <tbody>
            {users.map((u) => (
              <tr
                key={u.id}
                onClick={() => handleSelectUser(u)}
                className={`border-t cursor-pointer transition-colors ${
                  selectedUser?.id === u.id
                    ? "bg-brand-50"
                    : "hover:bg-brand-50/50"
                }`}
              >
                <td className="px-4 py-2">
                  <div className="flex items-center gap-2">
                    {u.avatar_url ? (
                      <img
                        src={u.avatar_url}
                        alt=""
                        className="w-7 h-7 rounded-full"
                      />
                    ) : (
                      <div className="w-7 h-7 rounded-full bg-gray-200 flex items-center justify-center text-xs font-semibold text-gray-500">
                        {(u.nickname || u.email || "?").charAt(0).toUpperCase()}
                      </div>
                    )}
                    <span className="font-medium">
                      {u.nickname || "-"}
                    </span>
                  </div>
                </td>
                <td className="px-4 py-2 text-gray-500">{u.email || "-"}</td>
                <td className="px-4 py-2 text-center">
                  <button
                    onClick={async (e) => {
                      e.stopPropagation();
                      try {
                        await api.updateAdminUserAdmin(u.id, !u.is_admin);
                        setUsers((prev) => prev.map((x) => x.id === u.id ? { ...x, is_admin: !u.is_admin } : x));
                      } catch (err) {
                        console.error("Failed to update admin:", err);
                        alert("관리자 권한 변경에 실패했습니다.");
                      }
                    }}
                    className={`inline-block px-2 py-0.5 rounded-full text-xs font-medium transition-colors ${
                      u.is_admin
                        ? "bg-green-100 text-green-700 hover:bg-green-200"
                        : "bg-gray-100 text-gray-400 hover:bg-gray-200"
                    }`}
                  >
                    {u.is_admin ? "ON" : "OFF"}
                  </button>
                </td>
                <td className="px-4 py-2 text-center">
                  {u.favorite_count > 0 ? (
                    <span className="inline-block px-2 py-0.5 bg-red-50 text-red-600 rounded-full text-xs font-medium">
                      {u.favorite_count}
                    </span>
                  ) : (
                    <span className="text-gray-300">0</span>
                  )}
                </td>
                <td className="px-4 py-2 text-center">
                  {u.review_count > 0 ? (
                    <span className="inline-block px-2 py-0.5 bg-brand-50 text-brand-600 rounded-full text-xs font-medium">
                      {u.review_count}
                    </span>
                  ) : (
                    <span className="text-gray-300">0</span>
                  )}
                </td>
                <td className="px-4 py-2 text-center">
                  {u.memo_count > 0 ? (
                    <span className="inline-block px-2 py-0.5 bg-purple-50 text-purple-600 rounded-full text-xs font-medium">
                      {u.memo_count}
                    </span>
                  ) : (
                    <span className="text-gray-300">0</span>
                  )}
                </td>
                <td className="px-4 py-2 text-gray-400 text-xs">
                  {u.created_at?.slice(0, 10) || "-"}
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>

      {/* Pagination */}
      {totalPages > 1 && (
        <div className="flex items-center justify-center gap-2">
          <button
            onClick={() => setPage((p) => Math.max(0, p - 1))}
            disabled={page === 0}
            className="px-3 py-1 text-sm border rounded disabled:opacity-30"
          >
            이전
          </button>
          <span className="text-sm text-gray-600">
            {page + 1} / {totalPages}
          </span>
          <button
            onClick={() => setPage((p) => Math.min(totalPages - 1, p + 1))}
            disabled={page >= totalPages - 1}
            className="px-3 py-1 text-sm border rounded disabled:opacity-30"
          >
            다음
          </button>
        </div>
      )}

      {/* Selected User Detail */}
      {selectedUser && (
        <div className="bg-surface rounded-lg shadow p-5 space-y-4">
          <div className="flex items-center gap-3 pb-3 border-b">
            {selectedUser.avatar_url ? (
              <img
                src={selectedUser.avatar_url}
                alt=""
                className="w-12 h-12 rounded-full"
              />
            ) : (
              <div className="w-12 h-12 rounded-full bg-gray-200 flex items-center justify-center text-lg font-semibold text-gray-500">
                {(selectedUser.nickname || selectedUser.email || "?").charAt(0).toUpperCase()}
              </div>
            )}
            <div>
              <div className="font-bold">{selectedUser.nickname || "-"}</div>
              <div className="text-sm text-gray-500">{selectedUser.email || "-"}</div>
              <div className="text-xs text-gray-400">
                {selectedUser.provider} · 가입: {selectedUser.created_at?.slice(0, 10)}
              </div>
            </div>
          </div>

          {detailLoading ? (
            <p className="text-sm text-gray-500">로딩 중...</p>
          ) : (
            <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
              {/* Favorites */}
              <div>
                <h3 className="font-semibold text-sm mb-2 text-red-600">
                  찜한 식당 ({favorites.length})
                </h3>
                {favorites.length === 0 ? (
                  <p className="text-xs text-gray-400">찜한 식당이 없습니다.</p>
                ) : (
                  <div className="space-y-1 max-h-64 overflow-y-auto">
                    {favorites.map((f) => (
                      <div
                        key={f.id}
                        className="flex items-center justify-between border rounded px-3 py-2 text-xs"
                      >
                        <div>
                          <span className="font-medium">{f.name}</span>
                          {f.region && (
                            <span className="ml-1.5 text-gray-400">{f.region}</span>
                          )}
                          {f.cuisine_type && (
                            <span className="ml-1.5 text-gray-400">· {f.cuisine_type}</span>
                          )}
                          {f.business_status === "CLOSED_PERMANENTLY" && (
                            <span className="ml-1.5 px-1 bg-red-100 text-red-600 rounded text-[10px]">
                              폐업
                            </span>
                          )}
                        </div>
                        {f.rating && (
                          <span className="text-yellow-500 shrink-0">
                            ★ {f.rating}
                          </span>
                        )}
                      </div>
                    ))}
                  </div>
                )}
              </div>

              {/* Reviews */}
              <div>
                <h3 className="font-semibold text-sm mb-2 text-brand-600">
                  작성한 리뷰 ({reviews.length})
                </h3>
                {reviews.length === 0 ? (
                  <p className="text-xs text-gray-400">작성한 리뷰가 없습니다.</p>
                ) : (
                  <div className="space-y-1 max-h-64 overflow-y-auto">
                    {reviews.map((r) => (
                      <div
                        key={r.id}
                        className="border rounded px-3 py-2 text-xs space-y-0.5"
                      >
                        <div className="flex items-center justify-between">
                          <span className="font-medium">
                            {r.restaurant_name || "알 수 없음"}
                          </span>
                          <span className="text-yellow-500 shrink-0">
                            {"★".repeat(Math.round(r.rating))} {r.rating}
                          </span>
                        </div>
                        {r.review_text && (
                          <p className="text-gray-600 line-clamp-2">
                            {r.review_text}
                          </p>
                        )}
                        <div className="text-gray-400 text-[10px]">
                          {r.visited_at && `방문: ${r.visited_at} · `}
                          {r.created_at?.slice(0, 10)}
                        </div>
                      </div>
                    ))}
                  </div>
                )}
              </div>

              {/* Memos */}
              <div>
                <h3 className="font-semibold text-sm mb-2 text-purple-600">
                  작성한 메모 ({memos.length})
                </h3>
                {memos.length === 0 ? (
                  <p className="text-xs text-gray-400">작성한 메모가 없습니다.</p>
                ) : (
                  <div className="space-y-1 max-h-64 overflow-y-auto">
                    {memos.map((m) => (
                      <div
                        key={m.id}
                        className="border border-purple-200 rounded px-3 py-2 text-xs space-y-0.5 bg-purple-50/30"
                      >
                        <div className="flex items-center justify-between">
                          <span className="font-medium">
                            {m.restaurant_name || "알 수 없음"}
                          </span>
                          {m.rating && (
                            <span className="text-yellow-500 shrink-0">
                              {"★".repeat(Math.round(m.rating))} {m.rating}
                            </span>
                          )}
                        </div>
                        {m.memo_text && (
                          <p className="text-gray-600 line-clamp-2">
                            {m.memo_text}
                          </p>
                        )}
                        <div className="text-gray-400 text-[10px]">
                          {m.visited_at && `방문: ${m.visited_at} · `}
                          {m.created_at?.slice(0, 10)}
                          <span className="ml-1 text-purple-400">비공개</span>
                        </div>
                      </div>
                    ))}
                  </div>
                )}
              </div>
            </div>
          )}
        </div>
      )}
    </div>
  );
}

/* ─── 데몬 설정 ─── */