import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import '../../services/water_service.dart';

/// 实时监测列表页面
class MonitorPage extends StatefulWidget {
  const MonitorPage({super.key});
  @override
  State<MonitorPage> createState() => _MonitorPageState();
}

class _MonitorPageState extends State<MonitorPage> {
  final WaterService _service = WaterService.instance;
  List<MonitorItem> _items = [];
  bool _isLoading = true;
  String? _error;
  MonitorType? _filterType;

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

  Future<void> _loadData() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });
    try {
      final data = await _service.getMonitorList();
      if (mounted) {
        setState(() {
          _items = data;
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _error = e.toString();
          _isLoading = false;
        });
      }
    }
  }

  List<MonitorItem> get _filteredItems {
    if (_filterType == null) return _items;
    return _items.where((item) => item.type == _filterType).toList();
  }

  int _countByStatus(DeviceStatus status) {
    return _items.where((item) => item.status == status).length;
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Scaffold(
      appBar: AppBar(
        title: const Text('实时监测'),
        centerTitle: true,
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: _isLoading ? null : _loadData,
          ),
        ],
      ),
      body: Column(
        children: [
          // 状态概览栏
          if (!_isLoading && _error == null) _buildStatusBar(theme),
          // 类型筛选
          if (!_isLoading && _error == null) _buildFilterBar(theme),
          // 列表内容
          Expanded(
            child: _buildBody(theme),
          ),
        ],
      ),
    );
  }

  Widget _buildStatusBar(ThemeData theme) {
    final online = _countByStatus(DeviceStatus.online);
    final offline = _countByStatus(DeviceStatus.offline);
    final warning = _countByStatus(DeviceStatus.warning);

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      color: theme.colorScheme.surfaceContainerHighest.withAlpha(100),
      child: Row(
        children: [
          _StatusBadge(label: '在线', count: online, color: Colors.green),
          const SizedBox(width: 16),
          _StatusBadge(label: '离线', count: offline, color: Colors.grey),
          const SizedBox(width: 16),
          _StatusBadge(label: '告警', count: warning, color: Colors.orange),
          const Spacer(),
          Text(
            '共 ${_items.length} 个监测点',
            style: theme.textTheme.bodySmall,
          ),
        ],
      ),
    );
  }

  Widget _buildFilterBar(ThemeData theme) {
    return SingleChildScrollView(
      scrollDirection: Axis.horizontal,
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      child: Row(
        children: [
          _FilterChip(
            label: '全部',
            selected: _filterType == null,
            onTap: () => setState(() => _filterType = null),
          ),
          const SizedBox(width: 8),
          ...MonitorType.values.map((type) {
            return Padding(
              padding: const EdgeInsets.only(right: 8),
              child: _FilterChip(
                label: type.label,
                selected: _filterType == type,
                onTap: () => setState(() => _filterType = type),
              ),
            );
          }),
        ],
      ),
    );
  }

  Widget _buildBody(ThemeData theme) {
    if (_isLoading) {
      return const Center(child: CircularProgressIndicator());
    }
    if (_error != null) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.error_outline, size: 48, color: theme.colorScheme.error),
            const SizedBox(height: 16),
            Text('加载失败', style: theme.textTheme.titleMedium),
            const SizedBox(height: 8),
            Text(_error!, style: theme.textTheme.bodySmall),
            const SizedBox(height: 16),
            FilledButton.icon(
              onPressed: _loadData,
              icon: const Icon(Icons.refresh),
              label: const Text('重试'),
            ),
          ],
        ),
      );
    }

    final items = _filteredItems;
    if (items.isEmpty) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.sensors_off, size: 48, color: Colors.grey.shade400),
            const SizedBox(height: 16),
            Text('暂无监测数据', style: theme.textTheme.titleMedium),
          ],
        ),
      );
    }

    return RefreshIndicator(
      onRefresh: _loadData,
      child: ListView.builder(
        padding: const EdgeInsets.all(12),
        itemCount: items.length,
        itemBuilder: (context, index) => _MonitorCard(item: items[index]),
      ),
    );
  }
}

/// 监测点卡片
class _MonitorCard extends StatelessWidget {
  final MonitorItem item;
  const _MonitorCard({required this.item});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final statusColor = Color(item.status.color);
    final timeFormat = DateFormat('HH:mm:ss');

    return Card(
      margin: const EdgeInsets.only(bottom: 10),
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(color: theme.colorScheme.outlineVariant.withAlpha(100)),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 标题行
            Row(
              children: [
                Container(
                  width: 8,
                  height: 8,
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: statusColor,
                  ),
                ),
                const SizedBox(width: 8),
                Expanded(
                  child: Text(
                    item.name,
                    style: theme.textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                ),
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                  decoration: BoxDecoration(
                    color: statusColor.withAlpha(30),
                    borderRadius: BorderRadius.circular(4),
                  ),
                  child: Text(
                    item.type.label,
                    style: TextStyle(fontSize: 11, color: statusColor),
                  ),
                ),
                const SizedBox(width: 8),
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                  decoration: BoxDecoration(
                    color: statusColor.withAlpha(30),
                    borderRadius: BorderRadius.circular(4),
                  ),
                  child: Text(
                    item.statusLabel,
                    style: TextStyle(fontSize: 11, color: statusColor),
                  ),
                ),
              ],
            ),
            const SizedBox(height: 12),
            // 数据行
            if (item.status != DeviceStatus.offline) ...[
              Wrap(
                spacing: 16,
                runSpacing: 8,
                children: [
                  if (item.flow != null)
                    _DataChip(icon: Icons.water_drop, label: '流量', value: '${item.flow!.toStringAsFixed(1)} m³/h'),
                  if (item.pressure != null)
                    _DataChip(icon: Icons.speed, label: '压力', value: '${item.pressure!.toStringAsFixed(2)} MPa'),
                  if (item.level != null)
                    _DataChip(icon: Icons.straighten, label: '液位', value: '${item.level!.toStringAsFixed(1)} m'),
                  if (item.ph != null)
                    _DataChip(icon: Icons.science, label: 'pH', value: item.ph!.toStringAsFixed(1)),
                  if (item.turbidity != null)
                    _DataChip(icon: Icons.blur_on, label: '浊度', value: '${item.turbidity!.toStringAsFixed(1)} NTU'),
                  if (item.chlorine != null)
                    _DataChip(icon: Icons.bubble_chart, label: '余氯', value: '${item.chlorine!.toStringAsFixed(2)} mg/L'),
                ],
              ),
              const SizedBox(height: 8),
            ] else
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 8),
                child: Text(
                  '设备离线，暂无数据',
                  style: TextStyle(color: Colors.grey.shade500, fontSize: 13),
                ),
              ),
            // 更新时间
            Row(
              mainAxisAlignment: MainAxisAlignment.end,
              children: [
                Icon(Icons.access_time, size: 12, color: Colors.grey.shade500),
                const SizedBox(width: 4),
                Text(
                  '更新于 ${timeFormat.format(item.updateTime)}',
                  style: TextStyle(fontSize: 11, color: Colors.grey.shade500),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

class _DataChip extends StatelessWidget {
  final IconData icon;
  final String label;
  final String value;

  const _DataChip({required this.icon, required this.label, required this.value});

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        Icon(icon, size: 14, color: Colors.grey.shade600),
        const SizedBox(width: 4),
        Text(
          '$label: ',
          style: TextStyle(fontSize: 12, color: Colors.grey.shade600),
        ),
        Text(
          value,
          style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600),
        ),
      ],
    );
  }
}

class _StatusBadge extends StatelessWidget {
  final String label;
  final int count;
  final Color color;

  const _StatusBadge({required this.label, required this.count, required this.color});

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        Container(
          width: 8,
          height: 8,
          decoration: BoxDecoration(shape: BoxShape.circle, color: color),
        ),
        const SizedBox(width: 4),
        Text('$label $count', style: const TextStyle(fontSize: 13)),
      ],
    );
  }
}

class _FilterChip extends StatelessWidget {
  final String label;
  final bool selected;
  final VoidCallback onTap;

  const _FilterChip({required this.label, required this.selected, required this.onTap});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(16),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 6),
        decoration: BoxDecoration(
          color: selected ? theme.colorScheme.primaryContainer : Colors.grey.shade100,
          borderRadius: BorderRadius.circular(16),
          border: selected
              ? Border.all(color: theme.colorScheme.primary, width: 1)
              : null,
        ),
        child: Text(
          label,
          style: TextStyle(
            fontSize: 13,
            color: selected ? theme.colorScheme.primary : Colors.grey.shade700,
            fontWeight: selected ? FontWeight.w600 : FontWeight.normal,
          ),
        ),
      ),
    );
  }
}