'use client';

import { useState, useMemo, useRef, useEffect } from "react";
import AdminSidebar from "@/app/components/AdminSidebar";
import ChevronDownSvg from "@/app/svgs/chevrondownsvg";
import DropdownIcon from "@/app/svgs/dropdownicon";
import BackArrowSvg from "@/app/svgs/backarrow";
import { getCourses, type Course } from "@/app/admin/courses/mockData";
import CloseXOSvg from "@/app/svgs/closexo";

type Lesson = {
  id: string;
  courseName: string; // 교육과정명
  lessonName: string; // 강좌명
  attachments: string; // 첨부파일 (예: "강좌영상 3개, VR콘텐츠 2개, 평가문제 1개")
  questionCount: number; // 학습 평가 문제 수
  createdBy: string; // 등록자
  createdAt: string; // 등록일
};

export default function AdminLessonsPage() {
  const [lessons, setLessons] = useState<Lesson[]>([]);
  const [currentPage, setCurrentPage] = useState(1);
  const [isRegistrationMode, setIsRegistrationMode] = useState(false);
  const [isDropdownOpen, setIsDropdownOpen] = useState(false);
  const dropdownRef = useRef<HTMLDivElement>(null);
  const [courses, setCourses] = useState<Course[]>([]);
  const [currentUser, setCurrentUser] = useState<string>("관리자");
  
  // 등록 폼 상태
  const [selectedCourse, setSelectedCourse] = useState<string>("");
  const [lessonName, setLessonName] = useState("");
  const [learningGoal, setLearningGoal] = useState("");
  const [courseVideoCount, setCourseVideoCount] = useState(0);
  const [courseVideoFiles, setCourseVideoFiles] = useState<string[]>([]);
  const [vrContentCount, setVrContentCount] = useState(0);
  const [vrContentFiles, setVrContentFiles] = useState<string[]>([]);
  const [questionFileCount, setQuestionFileCount] = useState(0);
  
  // 교육과정 목록 가져오기
  useEffect(() => {
    async function fetchCourses() {
      try {
        const data = await getCourses();
        setCourses(data);
      } catch (error) {
        console.error('교육과정 목록 로드 오류:', error);
        setCourses([]);
      }
    }
    fetchCourses();
  }, []);

  // 현재 사용자 정보 가져오기
  useEffect(() => {
    async function fetchCurrentUser() {
      try {
        const token = typeof window !== 'undefined' 
          ? (localStorage.getItem('token') || document.cookie
              .split('; ')
              .find(row => row.startsWith('token='))
              ?.split('=')[1])
          : null;

        if (!token) {
          return;
        }

        const apiUrl = process.env.NEXT_PUBLIC_API_BASE_URL 
          ? `${process.env.NEXT_PUBLIC_API_BASE_URL}/auth/me`
          : 'https://hrdi.coconutmeet.net/auth/me';

        const response = await fetch(apiUrl, {
          method: 'GET',
          headers: {
            'Content-Type': 'application/json',
            Authorization: `Bearer ${token}`,
          },
        });

        if (response.ok) {
          const data = await response.json();
          if (data.name) {
            setCurrentUser(data.name);
          }
        }
      } catch (error) {
        console.error('사용자 정보 조회 오류:', error);
      }
    }
    fetchCurrentUser();
  }, []);
  
  const totalCount = useMemo(() => lessons.length, [lessons]);
  
  const ITEMS_PER_PAGE = 10;
  const sortedLessons = useMemo(() => {
    return [...lessons].sort((a, b) => {
      // 생성일 내림차순 정렬 (최신 날짜가 먼저)
      return b.createdAt.localeCompare(a.createdAt);
    });
  }, [lessons]);
  
  const totalPages = Math.ceil(sortedLessons.length / ITEMS_PER_PAGE);
  const paginatedLessons = useMemo(() => {
    const startIndex = (currentPage - 1) * ITEMS_PER_PAGE;
    const endIndex = startIndex + ITEMS_PER_PAGE;
    return sortedLessons.slice(startIndex, endIndex);
  }, [sortedLessons, currentPage]);

  // 교육과정 옵션
  const courseOptions = useMemo(() => 
    courses.map(course => ({ 
      id: course.id, 
      name: course.courseName 
    }))
  , [courses]);

  // 외부 클릭 시 드롭다운 닫기
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (
        dropdownRef.current &&
        !dropdownRef.current.contains(event.target as Node)
      ) {
        setIsDropdownOpen(false);
      }
    };

    if (isDropdownOpen) {
      document.addEventListener("mousedown", handleClickOutside);
    }

    return () => {
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [isDropdownOpen]);

  const handleBackClick = () => {
    setIsRegistrationMode(false);
    // 폼 초기화
    setSelectedCourse("");
    setLessonName("");
    setLearningGoal("");
    setCourseVideoCount(0);
    setCourseVideoFiles([]);
    setVrContentCount(0);
    setVrContentFiles([]);
    setQuestionFileCount(0);
  };

  const handleRegisterClick = () => {
    setIsRegistrationMode(true);
  };

  const handleSaveClick = () => {
    // 유효성 검사
    if (!selectedCourse || !lessonName) {
      // TODO: 에러 메시지 표시
      return;
    }

    // 첨부파일 정보 문자열 생성
    const attachmentParts: string[] = [];
    if (courseVideoCount > 0) {
      attachmentParts.push(`강좌영상 ${courseVideoCount}개`);
    }
    if (vrContentCount > 0) {
      attachmentParts.push(`VR콘텐츠 ${vrContentCount}개`);
    }
    if (questionFileCount > 0) {
      attachmentParts.push(`평가문제 ${questionFileCount}개`);
    }
    const attachments = attachmentParts.length > 0 
      ? attachmentParts.join(', ') 
      : '없음';

    // 교육과정명 가져오기
    const courseName = courseOptions.find(c => c.id === selectedCourse)?.name || '';

    // 새 강좌 생성
    const newLesson: Lesson = {
      id: String(Date.now()),
      courseName,
      lessonName,
      attachments,
      questionCount: questionFileCount,
      createdBy: currentUser,
      createdAt: new Date().toISOString().split('T')[0],
    };

    // 강좌 목록에 추가
    setLessons(prev => [...prev, newLesson]);

    // 등록 모드 종료 및 폼 초기화
    setIsRegistrationMode(false);
    setSelectedCourse("");
    setLessonName("");
    setLearningGoal("");
    setCourseVideoCount(0);
    setCourseVideoFiles([]);
    setVrContentCount(0);
    setVrContentFiles([]);
    setQuestionFileCount(0);
  };

  return (
    <div className="min-h-screen flex flex-col bg-white">
      {/* 메인 레이아웃 */}
      <div className="flex flex-1 min-h-0 justify-center">
        <div className="w-[1440px] flex min-h-0">
          {/* 사이드바 */}
          <div className="flex">
            <AdminSidebar />
          </div>
          {/* 메인 콘텐츠 */}
          <main className="w-[1120px] bg-white">
            <div className="h-full flex flex-col px-8">
              {isRegistrationMode ? (
                /* 등록 모드 */
                <div className="flex flex-col h-full">
                  {/* 헤더 */}
                  <div className="h-[100px] flex items-center">
                    <div className="flex items-center gap-[12px]">
                      <button
                        type="button"
                        onClick={handleBackClick}
                        className="flex items-center justify-center size-[32px] cursor-pointer hover:opacity-80"
                        aria-label="뒤로가기"
                      >
                        <BackArrowSvg width={32} height={32} />
                      </button>
                      <h1 className="text-[24px] font-bold leading-[1.5] text-[#1b2027]">
                        강좌 등록
                      </h1>
                    </div>
                  </div>

                  {/* 폼 콘텐츠 */}
                  <div className="flex-1 overflow-y-auto pb-[80px] pt-[32px]">
                    <div className="flex flex-col gap-[40px]">
                      {/* 강좌 정보 */}
                      <div className="flex flex-col gap-[8px]">
                        <h2 className="text-[18px] font-bold leading-[1.5] text-[#1b2027]">
                          강좌 정보
                        </h2>
                        <div className="flex flex-col gap-[24px]">
                          {/* 교육 과정 */}
                          <div className="flex flex-col gap-[8px] max-w-[480px]">
                            <label className="text-[15px] font-semibold leading-[1.5] text-[#6c7682]">
                              교육 과정
                            </label>
                            <div className="relative" ref={dropdownRef}>
                              <button
                                type="button"
                                onClick={() => setIsDropdownOpen(!isDropdownOpen)}
                                className="w-full h-[40px] px-[12px] py-[8px] border border-[#dee1e6] rounded-[8px] bg-white flex items-center justify-between focus:outline-none focus:shadow-[inset_0_0_0_1px_#333c47] cursor-pointer"
                              >
                                <span className={`text-[16px] font-normal leading-[1.5] flex-1 text-left ${
                                  selectedCourse ? 'text-[#1b2027]' : 'text-[#6c7682]'
                                }`}>
                                  {selectedCourse 
                                    ? courseOptions.find(c => c.id === selectedCourse)?.name 
                                    : '교육과정을 선택해 주세요.'}
                                </span>
                                <DropdownIcon stroke="#8C95A1" className="shrink-0" />
                              </button>
                              {isDropdownOpen && (
                                <div className="absolute top-full left-0 right-0 mt-1 bg-white border border-[#dee1e6] rounded-[8px] shadow-lg z-20 max-h-[200px] overflow-y-auto">
                                  {courseOptions.map((course, index) => (
                                    <button
                                      key={course.id}
                                      type="button"
                                      onClick={() => {
                                        setSelectedCourse(course.id);
                                        setIsDropdownOpen(false);
                                      }}
                                      className={`w-full px-3 py-2 text-left text-[16px] font-normal leading-[1.5] hover:bg-[#f1f3f5] transition-colors cursor-pointer ${
                                        selectedCourse === course.id
                                          ? "bg-[#ecf0ff] text-[#1f2b91] font-semibold"
                                          : "text-[#1b2027]"
                                      } ${
                                        index === 0 ? "rounded-t-[8px]" : ""
                                      } ${
                                        index === courseOptions.length - 1 ? "rounded-b-[8px]" : ""
                                      }`}
                                    >
                                      {course.name}
                                    </button>
                                  ))}
                                </div>
                              )}
                            </div>
                          </div>

                          {/* 강좌명 */}
                          <div className="flex flex-col gap-[8px]">
                            <label className="text-[15px] font-semibold leading-[1.5] text-[#6c7682]">
                              강좌명
                            </label>
                            <input
                              type="text"
                              value={lessonName}
                              onChange={(e) => setLessonName(e.target.value)}
                              placeholder="강좌명을 입력해 주세요."
                              className="h-[40px] px-[12px] py-[8px] border border-[#dee1e6] rounded-[8px] bg-white text-[16px] font-normal leading-[1.5] text-[#1b2027] placeholder:text-[#b1b8c0] focus:outline-none focus:shadow-[inset_0_0_0_1px_#333c47]"
                            />
                          </div>

                          {/* 학습 목표 */}
                          <div className="flex flex-col gap-[8px]">
                            <label className="text-[15px] font-semibold leading-[1.5] text-[#6c7682]">
                              학습 목표
                            </label>
                            <div className="relative">
                              <textarea
                                value={learningGoal}
                                onChange={(e) => {
                                  if (e.target.value.length <= 1000) {
                                    setLearningGoal(e.target.value);
                                  }
                                }}
                                placeholder="내용을 입력해 주세요. (최대 1,000자)"
                                className="w-full h-[160px] px-[12px] py-[8px] border border-[#dee1e6] rounded-[8px] bg-white text-[16px] font-normal leading-[1.5] text-[#1b2027] placeholder:text-[#b1b8c0] focus:outline-none focus:shadow-[inset_0_0_0_1px_#333c47] resize-none"
                              />
                              <div className="absolute bottom-[8px] right-[12px]">
                                <p className="text-[13px] font-normal leading-[1.4] text-[#6c7682] text-right">
                                  {learningGoal.length}/1000
                                </p>
                              </div>
                            </div>
                          </div>
                        </div>
                      </div>

                      {/* 파일 첨부 */}
                      <div className="flex flex-col gap-[8px]">
                        <h2 className="text-[18px] font-bold leading-[1.5] text-[#1b2027]">
                          파일 첨부
                        </h2>
                        <div className="flex flex-col gap-[24px]">
                          {/* 강좌 영상 */}
                          <div className="flex flex-col gap-[8px]">
                            <div className="flex items-center justify-between h-[32px]">
                              <div className="flex items-center gap-[8px]">
                                <label className="text-[15px] font-semibold leading-[1.5] text-[#6c7682]">
                                  강좌 영상 ({courseVideoCount}/10)
                                </label>
                                <span className="text-[13px] font-normal leading-[1.4] text-[#8c95a1]">
                                  30MB 미만 파일
                                </span>
                              </div>
                              <label className="h-[32px] w-[62px] px-[4px] py-[3px] border border-[#8c95a1] rounded-[6px] bg-white text-[13px] font-medium leading-[1.4] text-[#4c5561] whitespace-nowrap hover:bg-gray-50 transition-colors cursor-pointer flex items-center justify-center">
                                <span>첨부</span>
                                <input
                                  type="file"
                                  multiple
                                  accept=".mp4,video/mp4"
                                  className="hidden"
                                  onChange={(e) => {
                                    const files = e.target.files;
                                    if (!files) return;

                                    const MAX_SIZE = 30 * 1024 * 1024; // 30MB
                                    const mp4Files: string[] = [];
                                    Array.from(files).forEach((file) => {
                                      // mp4 파일이고 30MB 이하인 파일만 필터링
                                      if (file.name.toLowerCase().endsWith('.mp4') && file.size <= MAX_SIZE) {
                                        mp4Files.push(file.name);
                                      }
                                    });

                                    if (courseVideoCount + mp4Files.length <= 10) {
                                      setCourseVideoFiles(prev => [...prev, ...mp4Files]);
                                      setCourseVideoCount(prev => prev + mp4Files.length);
                                    }
                                    // input 초기화 (같은 파일 다시 선택 가능하도록)
                                    e.target.value = '';
                                  }}
                                />
                              </label>
                            </div>
                            <div className="border border-[#dee1e6] rounded-[8px] bg-gray-50">
                              {courseVideoFiles.length === 0 ? (
                                <div className="h-[64px] flex items-center justify-center">
                                  <p className="text-[14px] font-normal leading-[1.5] text-[#8c95a1] text-center">
                                    강좌 주제별 영상 파일을 첨부해주세요.
                                  </p>
                                </div>
                              ) : (
                                <div className="flex flex-col py-[12px]">
                                  {courseVideoFiles.map((fileName, index) => (
                                    <div
                                      key={index}
                                      className="h-[40px] px-[20px] py-[12px] flex items-center gap-[12px]"
                                    >
                                      <p className="flex-1 text-[15px] font-normal leading-[1.5] text-[#333c47]">
                                        {fileName}
                                      </p>
                                      <button
                                        type="button"
                                        onClick={() => {
                                          setCourseVideoFiles(prev => prev.filter((_, i) => i !== index));
                                          setCourseVideoCount(prev => prev - 1);
                                        }}
                                        className="size-[16px] flex items-center justify-center cursor-pointer hover:opacity-70 transition-opacity shrink-0"
                                        aria-label="파일 삭제"
                                      >
                                        <CloseXOSvg />
                                      </button>
                                    </div>
                                  ))}
                                </div>
                              )}
                            </div>
                          </div>

                          {/* VR 콘텐츠 */}
                          <div className="flex flex-col gap-[8px]">
                            <div className="flex items-center justify-between h-[32px]">
                              <div className="flex items-center gap-[8px]">
                                <label className="text-[15px] font-semibold leading-[1.5] text-[#6c7682]">
                                  VR 콘텐츠 ({vrContentCount}/10)
                                </label>
                                <span className="text-[13px] font-normal leading-[1.4] text-[#8c95a1]">
                                  30MB 미만 파일
                                </span>
                              </div>
                              <label className="h-[32px] w-[62px] px-[4px] py-[3px] border border-[#8c95a1] rounded-[6px] bg-white text-[13px] font-medium leading-[1.4] text-[#4c5561] whitespace-nowrap hover:bg-gray-50 transition-colors cursor-pointer flex items-center justify-center">
                                <span>첨부</span>
                                <input
                                  type="file"
                                  multiple
                                  accept=".zip,application/zip"
                                  className="hidden"
                                  onChange={(e) => {
                                    const files = e.target.files;
                                    if (!files) return;

                                    const MAX_SIZE = 30 * 1024 * 1024; // 30MB
                                    const zipFiles: string[] = [];
                                    Array.from(files).forEach((file) => {
                                      // zip 파일이고 30MB 이하인 파일만 필터링
                                      if (file.name.toLowerCase().endsWith('.zip') && file.size <= MAX_SIZE) {
                                        zipFiles.push(file.name);
                                      }
                                    });

                                    if (vrContentCount + zipFiles.length <= 10) {
                                      setVrContentFiles(prev => [...prev, ...zipFiles]);
                                      setVrContentCount(prev => prev + zipFiles.length);
                                    }
                                    // input 초기화 (같은 파일 다시 선택 가능하도록)
                                    e.target.value = '';
                                  }}
                                />
                              </label>
                            </div>
                            <div className="border border-[#dee1e6] rounded-[8px] bg-gray-50">
                              {vrContentFiles.length === 0 ? (
                                <div className="h-[64px] flex items-center justify-center">
                                  <p className="text-[14px] font-normal leading-[1.5] text-[#8c95a1] text-center">
                                    VR 학습 체험용 콘텐츠 파일을 첨부해주세요.
                                  </p>
                                </div>
                              ) : (
                                <div className="flex flex-col py-[12px]">
                                  {vrContentFiles.map((fileName, index) => (
                                    <div
                                      key={index}
                                      className="h-[40px] px-[20px] py-[12px] flex items-center gap-[12px]"
                                    >
                                      <p className="flex-1 text-[15px] font-normal leading-[1.5] text-[#333c47]">
                                        {fileName}
                                      </p>
                                      <button
                                        type="button"
                                        onClick={() => {
                                          setVrContentFiles(prev => prev.filter((_, i) => i !== index));
                                          setVrContentCount(prev => prev - 1);
                                        }}
                                        className="size-[16px] flex items-center justify-center cursor-pointer hover:opacity-70 transition-opacity shrink-0"
                                        aria-label="파일 삭제"
                                      >
                                        <CloseXOSvg />
                                      </button>
                                    </div>
                                  ))}
                                </div>
                              )}
                            </div>
                          </div>

                          {/* 학습 평가 문제 */}
                          <div className="flex flex-col gap-[8px]">
                            <div className="flex items-center justify-between h-[32px]">
                              <div className="flex items-center gap-[8px]">
                                <label className="text-[15px] font-semibold leading-[1.5] text-[#6c7682]">
                                  학습 평가 문제
                                </label>
                                <span className="text-[13px] font-normal leading-[1.4] text-[#8c95a1]">
                                  CSV 파일 형식만 첨부 가능
                                </span>
                              </div>
                              <div className="flex items-center gap-[8px]">
                                <button
                                  type="button"
                                  className="h-[32px] px-[16px] py-[3px] border border-[#b1b8c0] rounded-[6px] bg-white text-[13px] font-medium leading-[1.4] text-[#b1b8c0] whitespace-nowrap hover:bg-gray-50 transition-colors cursor-pointer"
                                >
                                  다운로드
                                </button>
                                <label className="h-[32px] w-[62px] px-[4px] py-[3px] border border-[#8c95a1] rounded-[6px] bg-white text-[13px] font-medium leading-[1.4] text-[#4c5561] whitespace-nowrap hover:bg-gray-50 transition-colors cursor-pointer flex items-center justify-center">
                                  <span>첨부</span>
                                  <input
                                    type="file"
                                    accept=".csv"
                                    className="hidden"
                                    onChange={(e) => {
                                      const files = e.target.files;
                                      if (!files || files.length === 0) return;

                                      const file = files[0];
                                      // CSV 파일만 허용
                                      if (file.name.toLowerCase().endsWith('.csv')) {
                                        setQuestionFileCount(1);
                                      }
                                    }}
                                  />
                                </label>
                              </div>
                            </div>
                            <div className="h-[64px] border border-[#dee1e6] rounded-[8px] bg-gray-50 flex items-center justify-center">
                              <p className="text-[14px] font-normal leading-[1.5] text-[#8c95a1] text-center">
                                학습 평가용 문항 파일을 첨부해주세요.
                              </p>
                            </div>
                          </div>
                        </div>
                      </div>

                      {/* 액션 버튼 */}
                      <div className="flex items-center justify-end gap-[12px]">
                        <button
                          type="button"
                          onClick={handleBackClick}
                          className="h-[48px] px-[8px] rounded-[10px] bg-[#f1f3f5] text-[16px] font-semibold leading-[1.5] text-[#4c5561] min-w-[80px] hover:bg-[#e5e7eb] transition-colors cursor-pointer"
                        >
                          취소
                        </button>
                        <button
                          type="button"
                          onClick={handleSaveClick}
                          className="h-[48px] px-[16px] rounded-[10px] bg-[#1f2b91] text-[16px] font-semibold leading-[1.5] text-white hover:bg-[#1a2478] transition-colors cursor-pointer"
                        >
                          저장하기
                        </button>
                      </div>
                    </div>
                  </div>
                </div>
              ) : (
                /* 목록 모드 */
                <>
                  {/* 제목 영역 */}
                  <div className="h-[100px] flex items-center">
                    <h1 className="text-[24px] font-bold leading-[1.5] text-[#1b2027]">
                      강좌 관리
                    </h1>
                  </div>

                  {/* 헤더 영역 (제목과 콘텐츠 사이) */}
                  <div className="pt-2 pb-4 flex items-center justify-between">
                    <p className="text-[15px] font-medium leading-[1.5] text-[#333c47] whitespace-nowrap">
                      총 {totalCount}건
                    </p>
                    <button
                      type="button"
                      onClick={handleRegisterClick}
                      className="h-[40px] px-4 rounded-[8px] bg-[#1f2b91] text-[16px] font-semibold leading-[1.5] text-white whitespace-nowrap hover:bg-[#1a2478] transition-colors cursor-pointer"
                    >
                      등록하기
                    </button>
                  </div>

                  {/* 콘텐츠 영역 */}
                  <div className="flex-1 pt-2 flex flex-col">
                    {lessons.length === 0 ? (
                      <div className="rounded-lg border border-[#dee1e6] bg-white min-h-[400px] flex items-center justify-center">
                        <p className="text-[16px] font-medium leading-[1.5] text-[#333c47]">
                          <span className="block text-center">
                            등록된 강좌가 없습니다.
                            <br />
                            강좌를 등록해주세요.
                          </span>
                        </p>
                      </div>
                    ) : (
                      <>
                        <div className="rounded-[8px]">
                          <div className="w-full rounded-[8px] border border-[#dee1e6] overflow-visible">
                            <table className="min-w-full border-collapse">
                              <colgroup>
                                <col />
                                <col />
                                <col />
                                <col style={{ width: 140 }} />
                                <col style={{ width: 120 }} />
                                <col style={{ width: 120 }} />
                              </colgroup>
                              <thead>
                                <tr className="h-12 bg-gray-50 text-left">
                                  <th className="border-r border-[#dee1e6] px-4 text-[14px] font-semibold leading-[1.5] text-[#4c5561]">교육과정명</th>
                                  <th className="border-r border-[#dee1e6] px-4 text-[14px] font-semibold leading-[1.5] text-[#4c5561]">강좌명</th>
                                  <th className="border-r border-[#dee1e6] px-4 text-[14px] font-semibold leading-[1.5] text-[#4c5561]">첨부파일</th>
                                  <th className="border-r border-[#dee1e6] px-4 text-[14px] font-semibold leading-[1.5] text-[#4c5561]">학습 평가 문제 수</th>
                                  <th className="border-r border-[#dee1e6] px-4 text-[14px] font-semibold leading-[1.5] text-[#4c5561]">등록자</th>
                                  <th className="px-4 text-[14px] font-semibold leading-[1.5] text-[#4c5561]">등록일</th>
                                </tr>
                              </thead>
                              <tbody>
                                {paginatedLessons.map((lesson) => (
                                  <tr
                                    key={lesson.id}
                                    className="h-12 hover:bg-[#F5F7FF] transition-colors"
                                  >
                                    <td className="border-t border-r border-[#dee1e6] px-4 text-[13px] leading-[1.5] text-[#1b2027] whitespace-nowrap">
                                      {lesson.courseName}
                                    </td>
                                    <td className="border-t border-r border-[#dee1e6] px-4 text-[13px] leading-[1.5] text-[#1b2027] whitespace-nowrap">
                                      {lesson.lessonName}
                                    </td>
                                    <td className="border-t border-r border-[#dee1e6] px-4 text-[13px] leading-[1.5] text-[#1b2027]">
                                      {lesson.attachments}
                                    </td>
                                    <td className="border-t border-r border-[#dee1e6] px-4 text-[13px] leading-[1.5] text-[#1b2027] whitespace-nowrap">
                                      {lesson.questionCount}개
                                    </td>
                                    <td className="border-t border-r border-[#dee1e6] px-4 text-[13px] leading-[1.5] text-[#1b2027] whitespace-nowrap">
                                      {lesson.createdBy}
                                    </td>
                                    <td className="border-t border-[#dee1e6] px-4 text-[13px] leading-[1.5] text-[#1b2027] whitespace-nowrap">
                                      {lesson.createdAt}
                                    </td>
                                  </tr>
                                ))}
                              </tbody>
                            </table>
                          </div>
                        </div>
                        
                        {/* 페이지네이션 - 10개 초과일 때만 표시 */}
                        {lessons.length > ITEMS_PER_PAGE && (() => {
                          // 페이지 번호를 10단위로 표시
                          const pageGroup = Math.floor((currentPage - 1) / 10);
                          const startPage = pageGroup * 10 + 1;
                          const endPage = Math.min(startPage + 9, totalPages);
                          const visiblePages = Array.from({ length: endPage - startPage + 1 }, (_, i) => startPage + i);

                          return (
                            <div className="pt-8 pb-[32px] flex items-center justify-center">
                              <div className="flex items-center justify-center gap-[8px]">
                                {/* First (맨 앞으로) */}
                                <button
                                  type="button"
                                  onClick={() => setCurrentPage(1)}
                                  aria-label="맨 앞 페이지"
                                  className="flex items-center justify-center rounded-[1000px] p-[8.615px] size-[32px] text-[#333c47] disabled:opacity-40 cursor-pointer disabled:cursor-not-allowed"
                                  disabled={currentPage === 1}
                                >
                                  <div className="relative flex items-center justify-center w-full h-full">
                                    <ChevronDownSvg width={14.8} height={14.8} className="rotate-90 absolute left-[2px]" />
                                    <ChevronDownSvg width={14.8} height={14.8} className="rotate-90 absolute right-[2px]" />
                                  </div>
                                </button>

                                {/* Prev */}
                                <button
                                  type="button"
                                  onClick={() => setCurrentPage((p) => Math.max(1, p - 1))}
                                  aria-label="이전 페이지"
                                  className="flex items-center justify-center rounded-[1000px] p-[8.615px] size-[32px] text-[#333c47] disabled:opacity-40 cursor-pointer disabled:cursor-not-allowed"
                                  disabled={currentPage === 1}
                                >
                                  <ChevronDownSvg width={14.8} height={14.8} className="rotate-90" />
                                </button>

                                {/* Numbers */}
                                {visiblePages.map((n) => {
                                  const active = n === currentPage;
                                  return (
                                    <button
                                      key={n}
                                      type="button"
                                      onClick={() => setCurrentPage(n)}
                                      aria-current={active ? 'page' : undefined}
                                      className={[
                                        'flex items-center justify-center rounded-[1000px] size-[32px] cursor-pointer',
                                        active ? 'bg-[#ecf0ff]' : 'bg-white',
                                      ].join(' ')}
                                    >
                                      <span className="text-[16px] leading-[1.4] text-[#333c47]">{n}</span>
                                    </button>
                                  );
                                })}

                                {/* Next */}
                                <button
                                  type="button"
                                  onClick={() => setCurrentPage((p) => Math.min(totalPages, p + 1))}
                                  aria-label="다음 페이지"
                                  className="flex items-center justify-center rounded-[1000px] p-[8.615px] size-[32px] text-[#333c47] disabled:opacity-40 cursor-pointer disabled:cursor-not-allowed"
                                  disabled={currentPage === totalPages}
                                >
                                  <ChevronDownSvg width={14.8} height={14.8} className="-rotate-90" />
                                </button>

                                {/* Last (맨 뒤로) */}
                                <button
                                  type="button"
                                  onClick={() => setCurrentPage(totalPages)}
                                  aria-label="맨 뒤 페이지"
                                  className="flex items-center justify-center rounded-[1000px] p-[8.615px] size-[32px] text-[#333c47] disabled:opacity-40 cursor-pointer disabled:cursor-not-allowed"
                                  disabled={currentPage === totalPages}
                                >
                                  <div className="relative flex items-center justify-center w-full h-full">
                                    <ChevronDownSvg width={14.8} height={14.8} className="-rotate-90 absolute left-[2px]" />
                                    <ChevronDownSvg width={14.8} height={14.8} className="-rotate-90 absolute right-[2px]" />
                                  </div>
                                </button>
                              </div>
                            </div>
                          );
                        })()}
                      </>
                    )}
                  </div>
                </>
              )}
            </div>
          </main>
        </div>
      </div>
    </div>
  );
}

