nj/app/lib/features/teacher/views/teacher_page.dart

// 老师管理页面 — 创建班级 + 布置主题 + 点评日记

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'package:nuanji_app/core/theme/app_colors.dart';
import 'package:nuanji_app/core/theme/app_radius.dart';
import 'package:nuanji_app/data/repositories/class_repository.dart';
import 'package:nuanji_app/data/repositories/journal_repository.dart';
import 'package:nuanji_app/data/models/school_class.dart';
import '../../class_/bloc/class_bloc.dart';

/// 老师管理页面 — 教师专属功能入口
class TeacherPage extends StatelessWidget {
  const TeacherPage({super.key});

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) => ClassBloc(
        classRepository: context.read<ClassRepository>(),
        journalRepository: context.read<JournalRepository>(),
      )..add(const ClassLoadMyClasses()),
      child: const _TeacherView(),
    );
  }
}

class _TeacherView extends StatelessWidget {
  const _TeacherView();

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Scaffold(
      appBar: AppBar(title: const Text('教师管理')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 创建班级卡片
            _ActionCard(
              icon: Icons.add_circle_outline,
              iconColor: AppColors.accent,
              title: '创建班级',
              subtitle: '创建新班级并邀请学生加入',
              onTap: () => _showCreateClassDialog(context),
            ),
            const SizedBox(height: 12),

            // 布置主题卡片
            _ActionCard(
              icon: Icons.assignment_outlined,
              iconColor: AppColors.secondary,
              title: '布置主题',
              subtitle: '给班级布置日记写作主题',
              onTap: () => _showAssignTopicDialog(context),
            ),
            const SizedBox(height: 12),

            // 班级码管理
            _ActionCard(
              icon: Icons.qr_code,
              iconColor: AppColors.tertiary,
              title: '班级码管理',
              subtitle: '查看和重置班级码',
              onTap: () => _showClassCodes(context),
            ),
            const SizedBox(height: 24),

            // 最近点评
            Text(
              '快捷功能',
              style: theme.textTheme.titleMedium?.copyWith(fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 12),
            _ActionCard(
              icon: Icons.rate_review_outlined,
              iconColor: AppColors.rose,
              title: '点评日记',
              subtitle: '查看学生日记并点评',
              onTap: () => context.go('/class'),
            ),
            const SizedBox(height: 12),
            _ActionCard(
              icon: Icons.bar_chart_outlined,
              iconColor: colorScheme.primary,
              title: '班级统计',
              subtitle: '查看班级写作活跃度',
              onTap: () => context.go('/mood'),
            ),
          ],
        ),
      ),
    );
  }

  void _showCreateClassDialog(BuildContext context) {
    final nameController = TextEditingController();
    final schoolController = TextEditingController();

    showDialog(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('创建班级'),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            TextField(
              controller: nameController,
              decoration: const InputDecoration(
                labelText: '班级名称',
                hintText: '例如: 三年二班',
                border: OutlineInputBorder(),
              ),
            ),
            const SizedBox(height: 12),
            TextField(
              controller: schoolController,
              decoration: const InputDecoration(
                labelText: '学校名称（可选）',
                hintText: '例如: 阳光小学',
                border: OutlineInputBorder(),
              ),
            ),
          ],
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext),
            child: const Text('取消'),
          ),
          FilledButton(
            onPressed: () {
              if (nameController.text.trim().isNotEmpty) {
                context.read<ClassBloc>().add(ClassCreate(
                      name: nameController.text.trim(),
                      schoolName: schoolController.text.trim().isEmpty
                          ? null
                          : schoolController.text.trim(),
                    ));
                Navigator.pop(dialogContext);
                ScaffoldMessenger.of(context).showSnackBar(
                  const SnackBar(content: Text('班级创建成功！')),
                );
              }
            },
            child: const Text('创建'),
          ),
        ],
      ),
    );
  }

  void _showClassCodes(BuildContext context) {
    final classState = context.read<ClassBloc>().state;
    final classes = classState is ClassListLoaded ? classState.classes : <SchoolClass>[];

    if (classes.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请先创建班级')),
      );
      return;
    }

    showDialog(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('班级码管理'),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: classes.map((c) => ListTile(
            leading: const Icon(Icons.qr_code, color: AppColors.tertiary),
            title: Text(c.name),
            subtitle: Text('班级码: ${c.classCode} · ${c.memberCount} 人'),
            dense: true,
          )).toList(),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext),
            child: const Text('关闭'),
          ),
        ],
      ),
    );
  }

  void _showAssignTopicDialog(BuildContext context) {
    final titleController = TextEditingController();
    final descController = TextEditingController();

    // 从 ClassBloc 获取已加载的班级列表
    final classState = context.read<ClassBloc>().state;
    final classes = classState is ClassListLoaded ? classState.classes : <SchoolClass>[];

    // 无班级时提示先创建
    if (classes.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请先创建班级后再布置主题')),
      );
      return;
    }

    String selectedClassId = classes.first.id;

    showDialog(
      context: context,
      builder: (dialogContext) => StatefulBuilder(
        builder: (context, setDialogState) => AlertDialog(
          title: const Text('布置主题'),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              // 班级选择下拉框
              DropdownButtonFormField<String>(
                value: selectedClassId,
                decoration: const InputDecoration(
                  labelText: '选择班级',
                  border: OutlineInputBorder(),
                ),
                items: classes
                    .map((c) => DropdownMenuItem(
                          value: c.id,
                          child: Text(c.name),
                        ))
                    .toList(),
                onChanged: (v) {
                  if (v != null) setDialogState(() => selectedClassId = v);
                },
              ),
              const SizedBox(height: 12),
              TextField(
                controller: titleController,
                decoration: const InputDecoration(
                  labelText: '主题标题',
                  hintText: '例如: 我的周末',
                  border: OutlineInputBorder(),
                ),
              ),
              const SizedBox(height: 12),
              TextField(
                controller: descController,
                decoration: const InputDecoration(
                  labelText: '描述（可选）',
                  hintText: '主题要求和说明',
                  border: OutlineInputBorder(),
                ),
                maxLines: 3,
              ),
            ],
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(dialogContext),
              child: const Text('取消'),
            ),
            FilledButton(
              onPressed: () {
                if (titleController.text.trim().isNotEmpty) {
                  context.read<ClassBloc>().add(TopicAssign(
                        classId: selectedClassId,
                        title: titleController.text.trim(),
                        description: descController.text.trim().isEmpty
                            ? null
                            : descController.text.trim(),
                      ));
                  Navigator.pop(dialogContext);
                  ScaffoldMessenger.of(context).showSnackBar(
                    const SnackBar(content: Text('主题布置成功！')),
                  );
                }
              },
              child: const Text('布置'),
            ),
          ],
        ),
      ),
    );
  }
}

/// 操作卡片
class _ActionCard extends StatelessWidget {
  const _ActionCard({
    required this.icon,
    required this.iconColor,
    required this.title,
    required this.subtitle,
    required this.onTap,
  });

  final IconData icon;
  final Color iconColor;
  final String title;
  final String subtitle;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: AppRadius.mdBorder,
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: InkWell(
        onTap: onTap,
        borderRadius: AppRadius.mdBorder,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Row(
            children: [
              Container(
                width: 44,
                height: 44,
                decoration: BoxDecoration(
                  color: iconColor.withValues(alpha: 0.12),
                  borderRadius: BorderRadius.circular(12),
                ),
                child: Icon(icon, color: iconColor, size: 22),
              ),
              const SizedBox(width: 16),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(title, style: theme.textTheme.titleSmall?.copyWith(fontWeight: FontWeight.w600)),
                    const SizedBox(height: 2),
                    Text(subtitle, style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.5),
                    )),
                  ],
                ),
              ),
              Icon(Icons.chevron_right, color: colorScheme.onSurface.withValues(alpha: 0.3)),
            ],
          ),
        ),
      ),
    );
  }
}