import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../core/models/models.dart';
import '../../core/models/severity_mapping.dart';
import '../../core/network/api_exception.dart';
import '../../core/routing/route_paths.dart';
import '../../core/theme/theme_x.dart';
import '../../core/widgets/error_banner.dart';
import '../../core/widgets/slide_over_panel.dart';
import '../../core/widgets/status_pill.dart';
import '../../data/repositories/services_repository.dart';
import 'widgets/service_detail_body.dart';
import 'widgets/service_form_dialog.dart';
import 'widgets/services_table.dart';

class ServicesScreen extends ConsumerStatefulWidget {
  const ServicesScreen({super.key, this.serviceId});

  /// Present when routed via `/services?id=...` — renders the slide-over
  /// detail panel for this service alongside the still-visible table.
  final String? serviceId;

  @override
  ConsumerState<ServicesScreen> createState() => _ServicesScreenState();
}

class _ServicesScreenState extends ConsumerState<ServicesScreen> {
  final _busyIds = <String>{};

  Future<void> _run(String id, Future<void> Function() action, {String? successMessage}) async {
    setState(() => _busyIds.add(id));
    try {
      await action();
      ref.invalidate(servicesListProvider);
      if (mounted && successMessage != null) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(successMessage)));
      }
    } catch (e) {
      if (mounted) {
        final message = e is ApiException ? e.userMessage : e.toString();
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(message)));
      }
    } finally {
      if (mounted) setState(() => _busyIds.remove(id));
    }
  }

  void _toggleRunning(Service service) {
    final repo = ref.read(servicesRepositoryProvider);
    if (repo == null) return;
    _run(service.id, () => service.status == 'up' ? repo.stop(service.id) : repo.start(service.id));
  }

  void _backupNow(Service service) {
    final repo = ref.read(servicesRepositoryProvider);
    if (repo == null) return;
    _run(service.id, () => repo.backupNow(service.id), successMessage: 'Backup started');
  }

  Future<void> _delete(Service service) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Delete service?'),
        content: Text('This removes "${service.name}" from NodeMaster. It does not stop or delete the container.'),
        actions: [
          TextButton(onPressed: () => Navigator.of(context).pop(false), child: const Text('Cancel')),
          FilledButton(
            style: FilledButton.styleFrom(backgroundColor: context.status.critical),
            onPressed: () => Navigator.of(context).pop(true),
            child: const Text('Delete'),
          ),
        ],
      ),
    );
    if (confirmed != true) return;

    final repo = ref.read(servicesRepositoryProvider);
    if (repo == null) return;
    await _run(service.id, () => repo.delete(service.id));
    if (mounted) context.go(RoutePaths.services);
  }

  @override
  Widget build(BuildContext context) {
    final servicesAsync = ref.watch(servicesListProvider);

    return Stack(
      children: [
        Padding(
          padding: const EdgeInsets.all(24),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Text(
                    servicesAsync.maybeWhen(
                      data: (services) => '${services.length} SERVICES',
                      orElse: () => 'SERVICES',
                    ),
                    style: context.text.titleSmall,
                  ),
                  FilledButton.icon(
                    onPressed: () => showServiceFormDialog(context),
                    icon: const Icon(Icons.add, size: 17),
                    label: const Text('Add service'),
                  ),
                ],
              ),
              const SizedBox(height: 12),
              Expanded(
                child: servicesAsync.when(
                  loading: () => const Center(child: CircularProgressIndicator()),
                  error: (error, stackTrace) => Align(
                    alignment: Alignment.topCenter,
                    child: ErrorBanner(
                      message: error is ApiException ? error.userMessage : error.toString(),
                      onRetry: () => ref.invalidate(servicesListProvider),
                    ),
                  ),
                  data: (services) => SingleChildScrollView(
                    child: ServicesTable(
                      services: services,
                      busyServiceIds: _busyIds,
                      onRowTap: (service) => context.go(RoutePaths.serviceDetail(service.id)),
                      onToggleRunning: _toggleRunning,
                    ),
                  ),
                ),
              ),
            ],
          ),
        ),
        _buildDetailPanel(servicesAsync),
      ],
    );
  }

  Widget _buildDetailPanel(AsyncValue<List<Service>> servicesAsync) {
    final id = widget.serviceId;
    final service = servicesAsync.maybeWhen(
      data: (services) {
        for (final s in services) {
          if (s.id == id) return s;
        }
        return null;
      },
      orElse: () => null,
    );

    return SlideOverPanel(
      open: id != null,
      onClose: () => context.go(RoutePaths.services),
      title: service?.name ?? '',
      subtitle: service == null
          ? null
          : StatusPill(label: service.status, severity: severityForServiceStatus(service.status)),
      body: service == null
          ? const SizedBox.shrink()
          : ServiceDetailBody(service: service),
      headerActions: service == null
          ? const []
          : [
              IconButton(
                tooltip: 'Edit',
                icon: const Icon(Icons.edit_outlined, size: 18),
                onPressed: () => showServiceFormDialog(context, existing: service),
              ),
            ],
      actions: service == null
          ? const []
          : [
              OutlinedButton.icon(
                onPressed: () => _toggleRunning(service),
                icon: Icon(service.status == 'up' ? Icons.stop_rounded : Icons.play_arrow_rounded, size: 17),
                label: Text(service.status == 'up' ? 'Stop' : 'Start'),
              ),
              OutlinedButton.icon(
                onPressed: service.backup == null ? null : () => _backupNow(service),
                icon: const Icon(Icons.cloud_outlined, size: 17),
                label: const Text('Backup'),
              ),
              OutlinedButton.icon(
                style: OutlinedButton.styleFrom(foregroundColor: context.status.critical),
                onPressed: () => _delete(service),
                icon: const Icon(Icons.delete_outline, size: 17),
                label: const Text('Delete'),
              ),
            ],
    );
  }
}