water-management-system/mobile-app/lib/features/water_supply/pages/alert_page.dart

import 'package:flutter/material.dart';

/// 报警推送列表页面
class AlertPage extends StatefulWidget {
  const AlertPage({super.key});

  @override
  State<AlertPage> createState() => _AlertPageState();
}

class _AlertPageState extends State<AlertPage>
    with AutomaticKeepAliveClientMixin {
  List<Map<String, dynamic>> _alerts = [];
  bool _isLoading = true;

  @override
  bool get wantKeepAlive => true;

  @override
  void initState() {
    super.initState();
    _loadData();
  }

  void _loadData() {
    // 模拟数据加载
    Future.delayed(const Duration(milliseconds: 500), () {
      setState(() {
        _alerts = _generateMockAlerts();
        _isLoading = false;
      });
    });
  }

  List<Map<String, dynamic>> _generateMockAlerts() {
    return [
      {
        'id': 'AL-001',
        'title': '城东加压站压力异常',
        'level': 'critical',
        'station': '城东加压站',
        'content': '水压达到 3.2 MPa，超过警戒值',
        'time': '2026-06-17 08:30',
        'isRead': false,
      },
      {
        'id': 'AL-002',
        'title': '城西水厂流量下降',
        'level': 'warning',
        'station': '城西水厂',
        'content': '流量从 450 m³/h 降至 280 m³/h',
        'time': '2026-06-17 09:15',
        'isRead': false,
      },
      {
        'id': 'AL-003',
        'title': '南区配水站水质异常',
        'level': 'error',
        'station': '南区配水站',
        'content': '浊度指标超标，需立即处理',
        'time': '2026-06-17 10:20',
        'isRead': true,
      },
      {
        'id': 'AL-004',
        'title': '中心泵站设备维护',
        'level': 'info',
        'station': '中心泵站',
        'content': '计划性维护，预计停机 2 小时',
        'time': '2026-06-17 11:00',
        'isRead': true,
      },
      {
        'id': 'AL-005',
        'title': '高新区水厂水质恢复',
        'level': 'normal',
        'station': '高新区水厂',
        'content': '水质指标恢复正常，告警已解除',
        'time': '2026-06-16 15:45',
        'isRead': true,
      },
      {
        'id': 'AL-006',
        'title': '工业园加压站供电异常',
        'level': 'critical',
        'station': '工业园加压站',
        'content': '备用电源已启动，需尽快恢复主供电',
        'time': '2026-06-17 12:10',
        'isRead': false,
      },
    ];
  }

  Color _getLevelColor(String level) {
    switch (level) {
      case 'critical':
        return Colors.red;
      case 'error':
        return Colors.orange;
      case 'warning':
        return Colors.yellow;
      case 'info':
        return Colors.blue;
      default:
        return Colors.green;
    }
  }

  String _getLevelText(String level) {
    switch (level) {
      case 'critical':
        return '严重';
      case 'error':
        return '错误';
      case 'warning':
        return '警告';
      case 'info':
        return '信息';
      default:
        return '正常';
    }
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      appBar: AppBar(
        title: const Text('报警信息'),
        actions: [
          IconButton(
            icon: const Icon(Icons.filter_list),
            onPressed: () {
              _showFilterDialog();
            },
          ),
        ],
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : RefreshIndicator(
              onRefresh: () async {
                setState(() {
                  _isLoading = true;
                });
                _loadData();
              },
              child: ListView.builder(
                padding: const EdgeInsets.all(12),
                itemCount: _alerts.length,
                itemBuilder: (context, index) {
                  final alert = _alerts[index];
                  return _buildAlertCard(alert);
                },
              ),
            ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          _showAlertDetail();
        },
        child: const Icon(Icons.info),
      ),
    );
  }

  Widget _buildAlertCard(Map<String, dynamic> alert) {
    final isUnread = !alert['isRead'];
    
    return Card(
      margin: const EdgeInsets.only(bottom: 12),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                  decoration: BoxDecoration(
                    color: _getLevelColor(alert['level']).withOpacity(0.1),
                    borderRadius: BorderRadius.circular(12),
                    border: Border.all(
                      color: _getLevelColor(alert['level']),
                    ),
                  ),
                  child: Text(
                    _getLevelText(alert['level']),
                    style: TextStyle(
                      fontSize: 12,
                      color: _getLevelColor(alert['level']),
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
                if (isUnread)
                  Container(
                    margin: const EdgeInsets.only(left: 8),
                    width: 8,
                    height: 8,
                    decoration: BoxDecoration(
                      color: Colors.red,
                      shape: BoxShape.circle,
                    ),
                  ),
                const Spacer(),
                Text(
                  alert['time'],
                  style: TextStyle(fontSize: 12, color: Colors.grey[500]),
                ),
              ],
            ),
            const SizedBox(height: 12),
            Text(
              alert['title'],
              style: const TextStyle(
                fontSize: 16,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 8),
            Row(
              children: [
                const Icon(Icons.location_on, size: 16, color: Colors.grey),
                const SizedBox(width: 4),
                Text(
                  alert['station'],
                  style: TextStyle(fontSize: 14, color: Colors.grey[600]),
                ),
              ],
            ),
            const SizedBox(height: 8),
            Text(
              alert['content'],
              style: TextStyle(fontSize: 14, color: Colors.grey[700]),
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
            ),
          ],
        ),
      ),
    );
  }

  void _showFilterDialog() {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('筛选报警'),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            _buildFilterItem('严重', 'critical'),
            _buildFilterItem('错误', 'error'),
            _buildFilterItem('警告', 'warning'),
            _buildFilterItem('信息', 'info'),
          ],
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () {
              setState(() {
                _loadData();
              });
              Navigator.pop(context);
            },
            child: const Text('确定'),
          ),
        ],
      ),
    );
  }

  Widget _buildFilterItem(String text, String level) {
    return CheckboxListTile(
      title: Text(text),
      value: true,
      onChanged: (value) {},
    );
  }

  void _showAlertDetail() {
    // 显示最后一个未读告警详情
    final unreadAlerts = _alerts.where((alert) => !alert['isRead']).toList();
    if (unreadAlerts.isNotEmpty) {
      showDialog(
        context: context,
        builder: (context) => AlertDialog(
          title: Text(unreadAlerts.first['title']),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              _buildDetailRow('地点', unreadAlerts.first['station']),
              _buildDetailRow('时间', unreadAlerts.first['time']),
              _buildDetailRow('级别', _getLevelText(unreadAlerts.first['level'])),
              const SizedBox(height: 16),
              Text(unreadAlerts.first['content']),
            ],
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(context),
              child: const Text('关闭'),
            ),
            TextButton(
              onPressed: () {
                setState(() {
                  unreadAlerts.first['isRead'] = true;
                });
                Navigator.pop(context);
              },
              child: const Text('标记已读'),
            ),
          ],
        ),
      );
    }
  }

  Widget _buildDetailRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(
            '$label: ',
            style: const TextStyle(
              fontSize: 14,
              fontWeight: FontWeight.bold,
            ),
          ),
          Expanded(
            child: Text(value),
          ),
        ],
      ),
    );
  }
}