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

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

class DevicesTab extends StatefulWidget {
  const DevicesTab({super.key});

  @override
  State<DevicesTab> createState() => _DevicesTabState();
}

class _DevicesTabState extends State<DevicesTab> {
  late Future<List<Device>> _future;

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

  Future<List<Device>> _load() => context.read<ApiService>().devices();

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

  @override
  Widget build(BuildContext context) {
    return RefreshIndicator(
      onRefresh: _refresh,
      child: FutureBuilder<List<Device>>(
        future: _future,
        builder: (context, snapshot) {
          if (snapshot.connectionState != ConnectionState.done) {
            return const Center(child: CircularProgressIndicator());
          }
          if (snapshot.hasError) {
            return _ErrorList(message: '${snapshot.error}', onRetry: _refresh);
          }

          final devices = snapshot.data!;
          if (devices.isEmpty) {
            return _ErrorList(message: 'Устройств пока нет.', onRetry: _refresh);
          }

          return ListView.separated(
            physics: const AlwaysScrollableScrollPhysics(),
            itemCount: devices.length,
            separatorBuilder: (context, index) => const Divider(height: 1),
            itemBuilder: (context, index) {
              final device = devices[index];
              return ListTile(
                title: Text(device.name),
                subtitle: Text('${device.zone?.name ?? '—'} · ${device.deviceType?.code ?? device.protocol}'),
                trailing: StatusBadge(status: device.status),
                onTap: () => Navigator.of(context).push(
                  MaterialPageRoute(builder: (_) => DeviceDetailScreen(deviceId: device.id)),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

class _ErrorList extends StatelessWidget {
  const _ErrorList({required this.message, required this.onRetry});

  final String message;
  final Future<void> Function() onRetry;

  @override
  Widget build(BuildContext context) {
    return ListView(
      physics: const AlwaysScrollableScrollPhysics(),
      children: [
        Padding(
          padding: const EdgeInsets.symmetric(vertical: 64, horizontal: 24),
          child: Column(
            children: [
              Text(message, textAlign: TextAlign.center),
              const SizedBox(height: 12),
              TextButton(onPressed: onRetry, child: const Text('Повторить')),
            ],
          ),
        ),
      ],
    );
  }
}