import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:dio/dio.dart';
import '../../../core/models/vehicle.dart';
import '../providers/dashboard_providers.dart';
import '../../../widgets/vehicle_card.dart';
import '../../../widgets/loading_list.dart';
import '../../../widgets/error_view.dart';
import 'dashboard_shell.dart';
import 'vehicle_form_screen.dart';

class VehiclesScreen extends ConsumerStatefulWidget {
  const VehiclesScreen({super.key});

  @override
  ConsumerState<VehiclesScreen> createState() => _VehiclesScreenState();
}

class _VehiclesScreenState extends ConsumerState<VehiclesScreen> {
  String? _statusFilter;
  final _searchController = TextEditingController();
  String _search = '';

  @override
  void dispose() {
    _searchController.dispose();
    super.dispose();
  }

  VehicleQuery get _params => (
    page: 1,
    pageSize: 100,
    status: null,
  );

  List<Vehicle> _filterVehicles(List<Vehicle> vehicles) {
    final query = _search.trim().toLowerCase();
    final status = _statusFilter;

    return vehicles.where((vehicle) {
      if (status != null && vehicle.status != status) {
        return false;
      }
      if (query.isEmpty) {
        return true;
      }
      final haystack = [
        vehicle.displayName,
        vehicle.licensePlate,
        vehicle.status,
        vehicle.category,
      ].join(' ').toLowerCase();
      return haystack.contains(query);
    }).toList();
  }

  String _errorMessage(Object error) {
    if (error is DioException) {
      final data = error.response?.data;
      if (data is Map<String, dynamic>) {
        final message = data['message'];
        if (message is String && message.isNotEmpty) {
          return message;
        }
      }
    }
    return 'Failed to load vehicles';
  }

  @override
  Widget build(BuildContext context) {
    final vehiclesAsync = ref.watch(vehiclesProvider(_params));

    return DashboardShell(
      floatingActionButton: FloatingActionButton(
        onPressed: () async {
          final result = await Navigator.of(context).push<bool>(
            MaterialPageRoute(builder: (_) => const VehicleFormScreen()),
          );
          if (result == true) ref.invalidate(vehiclesProvider(_params));
        },
        child: const Icon(Icons.add),
      ),
      appBar: AppBar(
        title: const Text('Fleet'),
        bottom: PreferredSize(
          preferredSize: const Size.fromHeight(60),
          child: Padding(
            padding: const EdgeInsets.fromLTRB(16, 0, 16, 8),
            child: TextField(
              controller: _searchController,
              decoration: const InputDecoration(
                hintText: 'Search vehicles...',
                prefixIcon: Icon(Icons.search, size: 20),
                contentPadding: EdgeInsets.symmetric(vertical: 8),
              ),
              onChanged: (v) => setState(() => _search = v),
            ),
          ),
        ),
        actions: [
          PopupMenuButton<String?>(
            icon: Icon(
              Icons.filter_list,
              color: _statusFilter != null ? const Color(0xFF1A56DB) : null,
            ),
            onSelected: (v) => setState(() => _statusFilter = v),
            itemBuilder: (_) => [
              const PopupMenuItem(value: null, child: Text('All')),
              const PopupMenuItem(value: 'AVAILABLE', child: Text('Available')),
              const PopupMenuItem(value: 'RENTED', child: Text('Rented')),
              const PopupMenuItem(
                value: 'MAINTENANCE',
                child: Text('Maintenance'),
              ),
            ],
          ),
        ],
      ),
      body: vehiclesAsync.when(
        loading: () => const LoadingList(itemHeight: 240),
        error: (e, _) => ErrorView(
          message: _errorMessage(e),
          onRetry: () => ref.invalidate(vehiclesProvider(_params)),
        ),
        data: (res) {
          final filteredVehicles = _filterVehicles(res.data);

          return filteredVehicles.isEmpty
              ? const Center(
                child: Text(
                  'No vehicles found',
                  style: TextStyle(color: Color(0xFF9CA3AF)),
                ),
              )
              : RefreshIndicator(
                  onRefresh: () async =>
                      ref.invalidate(vehiclesProvider(_params)),
                  child: GridView.builder(
                    padding: const EdgeInsets.all(16),
                    gridDelegate:
                        const SliverGridDelegateWithFixedCrossAxisCount(
                      crossAxisCount: 1,
                      mainAxisExtent: 240,
                      mainAxisSpacing: 12,
                    ),
                    itemCount: filteredVehicles.length,
                    itemBuilder: (_, i) => VehicleCard(
                      vehicle: filteredVehicles[i],
                      onTap: () => context.push(
                        '/dashboard/fleet/${filteredVehicles[i].id}',
                      ),
                    ),
                  ),
                );
        },
      ),
    );
  }
}