// 👨‍🏫 교사 대시보드. 실시간 출석 확인, 학생 계정 관리 화면으로 가는 메뉴만 담당한다.
import 'package:flutter/material.dart';
import 'device_checkout_ledger_page.dart';
import 'login_screen.dart';
import 'teacher_attendance_page.dart';
import 'teacher_student_management_page.dart';

// ==========================================
// 👨‍🏫 4. 선생님 대시보드 (기존 3초 타이머 완벽 유지)
// ==========================================
class TeacherDashboard extends StatefulWidget {
  final String? teacherId;
  final String? teacherName;

  const TeacherDashboard({super.key, this.teacherId, this.teacherName});

  @override
  State<TeacherDashboard> createState() => _TeacherDashboardState();
}

class _TeacherDashboardState extends State<TeacherDashboard> {
  // 🧼 [수정] 사용하지 않던 _isLoading 변수를 삭제하여 경고를 완벽히 해결했습니다!

  @override
  Widget build(BuildContext context) {
    // 다른 화면에서 null이 넘어왔을 때를 대비한 안전망 방탄 코드
    final String displayName = widget.teacherName ?? "간편인증 선생";
    final String displayId = widget.teacherId ?? "간편인증";

    return Scaffold(
      backgroundColor: Colors.grey[100],
      appBar: AppBar(
        title: const Text(
          '👨‍🏫 TEACHER PORTAL',
          style: TextStyle(fontWeight: FontWeight.bold, letterSpacing: 1.2),
        ),
        centerTitle: true,
        backgroundColor: Colors.green[700], // 교사 전용 그린 테마 컬러
        foregroundColor: Colors.white,
        elevation: 0,
        actions: [
          IconButton(
            icon: const Icon(Icons.logout_rounded),
            onPressed: () => Navigator.pushReplacement(
              context,
              MaterialPageRoute(builder: (context) => const LoginScreen()),
            ),
          ),
        ],
      ),
      body: SingleChildScrollView(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 💳 [상단 배너 가이드] StudentDashboard와 100% 일치하는 프로필 카드 레이아웃
            Container(
              width: double.infinity,
              padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 28),
              decoration: BoxDecoration(
                color: Colors.green[700],
                borderRadius: const BorderRadius.only(
                  bottomLeft: Radius.circular(32),
                  bottomRight: Radius.circular(32),
                ),
              ),
              child: Row(
                children: [
                  Container(
                    padding: const EdgeInsets.all(4),
                    decoration: const BoxDecoration(
                      color: Colors.white,
                      shape: BoxShape.circle,
                    ),
                    child: CircleAvatar(
                      radius: 30,
                      backgroundColor: Colors.green[50],
                      child: Icon(
                        Icons.admin_panel_settings_rounded,
                        size: 32,
                        color: Colors.green[700],
                      ),
                    ),
                  ),
                  const SizedBox(width: 18),
                  Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        '$displayName 님',
                        style: const TextStyle(
                          fontSize: 22,
                          fontWeight: FontWeight.bold,
                          color: Colors.white,
                        ),
                      ),
                      const SizedBox(height: 4),
                      Text(
                        '교직원 번호: $displayId | 교사 권한 활성화됨',
                        style: TextStyle(
                          color: Colors.white.withValues(alpha: 0.8),
                          fontSize: 14,
                        ),
                      ),
                    ],
                  ),
                ],
              ),
            ),
            const SizedBox(height: 32),

            // 🏷️ [세로 바 타이틀 인디케이터] 구조 일치화
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 24.0),
              child: Row(
                children: [
                  Container(
                    width: 4,
                    height: 18,
                    decoration: BoxDecoration(
                      color: Colors.green[700],
                      borderRadius: BorderRadius.circular(2),
                    ),
                  ),
                  const SizedBox(width: 10),
                  const Text(
                    '스마트 교사용 관리 메뉴',
                    style: TextStyle(
                      fontSize: 18,
                      fontWeight: FontWeight.bold,
                      color: Colors.black87,
                    ),
                  ),
                ],
              ),
            ),
            const SizedBox(height: 16),

            // 📊 [그리드 레이아웃 메뉴] 시후의 카드 컴포넌트 스타일 적용
            // 🖥️ 데스크톱 브라우저에서 카드가 지나치게 커지지 않도록 최대 너비를 제한한다.
            Center(
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 700),
                child: Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 24.0),
                  child: GridView.count(
                    shrinkWrap: true,
                    physics: const NeverScrollableScrollPhysics(),
                    crossAxisCount: 2,
                    crossAxisSpacing: 16,
                    mainAxisSpacing: 16,
                    childAspectRatio: 0.95,
                    children: [
                      _buildModernCard(
                        icon: Icons.assignment_turned_in_rounded,
                        title: '실시간 출석 확인',
                        subtitle: '학생 제출 로그 모니터링',
                        color: Colors.blue,
                        onTap: () => Navigator.push(
                          context,
                          MaterialPageRoute(
                            builder: (context) => const TeacherAttendancePage(),
                          ),
                        ),
                      ),
                      _buildModernCard(
                        icon: Icons.manage_accounts_rounded,
                        title: '학생 계정 관리',
                        subtitle: '계정 추가 및 강제 리셋',
                        color: Colors.orange,
                        onTap: () => Navigator.push(
                          context,
                          MaterialPageRoute(
                            builder: (context) =>
                                const TeacherStudentManagementPage(),
                          ),
                        ),
                      ),
                      _buildModernCard(
                        icon: Icons.tablet_mac_rounded,
                        title: '스마트기기 반출 대장',
                        subtitle: '패드 반출 신청 승인/거절',
                        color: Colors.teal,
                        onTap: () => Navigator.push(
                          context,
                          MaterialPageRoute(
                            builder: (context) =>
                                const DeviceCheckoutLedgerPage(),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            ),
            const SizedBox(height: 32),
          ],
        ),
      ),
    );
  }

  // 💎 [시후 대시보드 전용 카드 위젯 이식 완료]
  Widget _buildModernCard({
    required IconData icon,
    required String title,
    required String subtitle,
    required Color color,
    required VoidCallback onTap,
    bool isActionButton = false,
    bool isLoading = false,
  }) {
    return InkWell(
      onTap: isLoading ? null : onTap,
      borderRadius: BorderRadius.circular(24),
      child: Ink(
        padding: const EdgeInsets.all(20),
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(24),
          boxShadow: [
            BoxShadow(
              color: Colors.black.withValues(alpha: 0.04),
              blurRadius: 16,
              offset: const Offset(0, 4),
            ),
          ],
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Container(
              padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(
                color: color.withValues(alpha: 0.1),
                borderRadius: BorderRadius.circular(16),
              ),
              child: Icon(icon, color: color, size: 28),
            ),
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Expanded(
                      child: Text(
                        title,
                        style: const TextStyle(
                          fontSize: 15,
                          fontWeight: FontWeight.bold,
                          color: Colors.black87,
                        ),
                      ),
                    ),
                    if (isLoading)
                      const SizedBox(
                        width: 16,
                        height: 16,
                        child: CircularProgressIndicator(strokeWidth: 2),
                      )
                    else if (isActionButton)
                      Icon(
                        Icons.touch_app_rounded,
                        size: 16,
                        color: color.withValues(alpha: 0.5),
                      ),
                  ],
                ),
                const SizedBox(height: 4),
                Text(
                  subtitle,
                  style: TextStyle(
                    fontSize: 12,
                    color: Colors.grey[500],
                    height: 1.2,
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}