import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../core/api_client.dart';
import '../core/api_service.dart';
import '../models/device.dart';
import '../widgets/status_badge.dart';

class DeviceDetailScreen extends StatefulWidget {
  const DeviceDetailScreen({super.key, required this.deviceId});

  final int deviceId;

  @override
  State<DeviceDetailScreen> createState() => _DeviceDetailScreenState();
}

class _DeviceDetailScreenState extends State<DeviceDetailScreen> {
  late Future<DeviceDetail> _future;
  bool _isSendingCommand = false;

  @override
  void initState() {
    super.initState();
    _future = _load();
  }

  Future<DeviceDetail> _load() => context.read<ApiService>().device(widget.deviceId);

  Future<void> _refresh() async {
    final future = _load();
    setState(() => _future = future);
    await future;
  }

  Future<void> _runCommand(Future<String> Function() command) async {
    setState(() => _isSendingCommand = true);
    try {
      final message = await command();
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(message)));
      await _refresh();
    } on ApiException catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(e.message)));
    } finally {
      if (mounted) setState(() => _isSendingCommand = false);
    }
  }

  Future<void> _promptSetLevel(int deviceId) async {
    final apiService = context.read<ApiService>();
    double level = 50;

    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => StatefulBuilder(
        builder: (context, setDialogState) => AlertDialog(
          title: const Text('Установить уровень'),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text('${level.round()}'),
              Slider(
                value: level,
                min: 0,
                max: 100,
                divisions: 100,
                onChanged: (value) => setDialogState(() => level = value),
              ),
            ],
          ),
          actions: [
            TextButton(onPressed: () => Navigator.pop(context, false), child: const Text('Отмена')),
            FilledButton(onPressed: () => Navigator.pop(context, true), child: const Text('Отправить')),
          ],
        ),
      ),
    );

    if (confirmed == true) {
      await _runCommand(() => apiService.setLevel(deviceId, level));
    }
  }

  @override
  Widget build(BuildContext context) {
    final apiService = context.read<ApiService>();

    return Scaffold(
      appBar: AppBar(title: const Text('Устройство')),
      body: RefreshIndicator(
        onRefresh: _refresh,
        child: FutureBuilder<DeviceDetail>(
          future: _future,
          builder: (context, snapshot) {
            if (snapshot.connectionState != ConnectionState.done) {
              return const Center(child: CircularProgressIndicator());
            }
            if (snapshot.hasError) {
              return ListView(
                physics: const AlwaysScrollableScrollPhysics(),
                children: [
                  Padding(
                    padding: const EdgeInsets.all(24),
                    child: Text('${snapshot.error}', textAlign: TextAlign.center),
                  ),
                ],
              );
            }

            final detail = snapshot.data!;
            final device = detail.device;
            final capabilities = device.deviceType?.capabilities ?? const [];

            return ListView(
              physics: const AlwaysScrollableScrollPhysics(),
              padding: const EdgeInsets.all(16),
              children: [
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Expanded(
                      child: Text(device.name, style: Theme.of(context).textTheme.headlineSmall),
                    ),
                    StatusBadge(status: device.status),
                  ],
                ),
                const SizedBox(height: 4),
                Text('${device.zone?.name ?? '—'} · ${device.deviceType?.code ?? device.protocol}'),
                if (detail.lastSeen != null)
                  Padding(
                    padding: const EdgeInsets.only(top: 4),
                    child: Text('Последний сигнал: ${detail.lastSeen}'),
                  ),
                const SizedBox(height: 24),
                if (capabilities.contains('turn_on') || capabilities.contains('turn_off'))
                  Row(
                    children: [
                      if (capabilities.contains('turn_on'))
                        Expanded(
                          child: FilledButton(
                            onPressed: _isSendingCommand ? null : () => _runCommand(() => apiService.turnOn(device.id)),
                            child: const Text('Включить'),
                          ),
                        ),
                      if (capabilities.contains('turn_on') && capabilities.contains('turn_off'))
                        const SizedBox(width: 12),
                      if (capabilities.contains('turn_off'))
                        Expanded(
                          child: OutlinedButton(
                            onPressed:
                                _isSendingCommand ? null : () => _runCommand(() => apiService.turnOff(device.id)),
                            child: const Text('Выключить'),
                          ),
                        ),
                    ],
                  ),
                if (capabilities.contains('set_level')) ...[
                  const SizedBox(height: 12),
                  OutlinedButton(
                    onPressed: _isSendingCommand ? null : () => _promptSetLevel(device.id),
                    child: const Text('Установить уровень'),
                  ),
                ],
                if (detail.reportedState.isNotEmpty) ...[
                  const SizedBox(height: 24),
                  Text('Сообщённое состояние', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  _KeyValueTable(data: detail.reportedState),
                ],
                if (detail.telemetry.isNotEmpty) ...[
                  const SizedBox(height: 24),
                  Text('История показаний', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  ...detail.telemetry.map(
                    (reading) => ListTile(
                      contentPadding: EdgeInsets.zero,
                      title: Text('${reading.sensorType}: ${reading.value}'),
                      subtitle: Text(reading.recordedAt),
                      dense: true,
                    ),
                  ),
                ],
              ],
            );
          },
        ),
      ),
    );
  }
}

class _KeyValueTable extends StatelessWidget {
  const _KeyValueTable({required this.data});

  final Map<String, dynamic> data;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: data.entries
          .map((entry) => Padding(
                padding: const EdgeInsets.symmetric(vertical: 2),
                child: Text('${entry.key}: ${entry.value}'),
              ))
          .toList(),
    );
  }
}