import 'package:flutter/material.dart';
import 'package:flutter_slidable/flutter_slidable.dart';
import 'package:inventory_system/services/manufacturer_service.dart';
import 'package:inventory_system/screens/bottom_nav_bar.dart';
import 'package:inventory_system/screens/nav_bar.dart';
import 'package:inventory_system/screens/title_bar.dart';

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

  @override
  State<ManufacturerScreen> createState() => _ManufacturerScreenState();
}

class _ManufacturerScreenState extends State<ManufacturerScreen> {
  int _selectedIndex = 0;
  final ManufacturerService _manufacturerService = ManufacturerService();
  late Future<List<dynamic>> _manufacturersFuture;

  List<dynamic> _allManufacturers = [];
  List<dynamic> _filteredManufacturers = [];
  final TextEditingController _searchController = TextEditingController();
  final TextEditingController _formController = TextEditingController();

  @override
  void initState() {
    super.initState();
    _manufacturersFuture = _fetchManufacturers();
    _searchController.addListener(_onSearchChanged);
  }

  Future<List<dynamic>> _fetchManufacturers() async {
    try {
      final manufacturers = await _manufacturerService.fetchManufacturers();
      
      manufacturers.sort((a, b) {
        final nameA = a['manufacturerName']?.toString().toLowerCase() ?? '';
        final nameB = b['manufacturerName']?.toString().toLowerCase() ?? '';
        return nameA.compareTo(nameB);
      });

      if (mounted) {
        setState(() {
          _allManufacturers = manufacturers;
          _filteredManufacturers = manufacturers;
        });
      }
      return manufacturers;
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Failed to load manufacturers: $e'), backgroundColor: Colors.red),
        );
      }
      rethrow;
    }
  }

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

  void _onSearchChanged() {
    final query = _searchController.text.toLowerCase();
    setState(() {
      _filteredManufacturers = _allManufacturers.where((manufacturer) {
        final name = manufacturer['manufacturerName']?.toString().toLowerCase() ?? '';
        return name.contains(query);
      }).toList();
    });
  }

  void _showFormDialog({Map<String, dynamic>? manufacturer}) {
    final isEdit = manufacturer != null;
    _formController.text = isEdit ? manufacturer['manufacturerName'] : '';

    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
        title: Text(isEdit ? 'Edit Manufacturer' : 'Add Manufacturer'),
        content: TextField(
          controller: _formController,
          autofocus: true,
          decoration: InputDecoration(
            labelText: 'Manufacturer Name',
            border: OutlineInputBorder(borderRadius: BorderRadius.circular(12)),
          ),
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context), child: const Text('Cancel')),
          ElevatedButton(
            onPressed: () => _submitForm(isEdit, manufacturer?['manufacturerId']),
            child: const Text('Save'),
          ),
        ],
      ),
    );
  }

  void _submitForm(bool isEdit, int? id) async {
    if (_formController.text.isEmpty) return;

    Navigator.pop(context);
    final String newName = _formController.text;

    try {
      if (isEdit) {
        await _manufacturerService.updateManufacturer(id!, newName);
      } else {
        await _manufacturerService.addManufacturer(newName);
      }

      if (!mounted) return;

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(isEdit ? 'Manufacturer updated' : 'Manufacturer added'),
          backgroundColor: Colors.green,
        ),
      );

      _fetchManufacturers();

    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('Operation failed: $e'),
          backgroundColor: Colors.red,
        ),
      );
    }
  }

  void _confirmDelete(int id, String name) {
    showDialog(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text('Delete Manufacturer'),
        content: Text('Are you sure you want to delete $name?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext),
            child: const Text('Cancel'),
          ),
          TextButton(
            onPressed: () async {
              try {
                await _manufacturerService.deleteManufacturer(id);

                Navigator.pop(dialogContext);

                if (!mounted) return;
                ScaffoldMessenger.of(context).showSnackBar(
                  const SnackBar(
                    content: Text('Manufacturer deleted successfully'),
                    backgroundColor: Colors.green,
                  ),
                );

                await _fetchManufacturers(); // Refresh only on success

              } catch (e) {
                Navigator.pop(dialogContext);

                if (!mounted) return;
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(
                    content: Text('Deletion failed: $e'),
                    backgroundColor: Colors.red,
                  ),
                );
              }
            },
            child: const Text('Delete', style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFFF5F5F7),
      appBar: const TitleBar(title: 'Manufacturer'),
      drawer: const NavBar(isAdmin: true, selectedScreen: AppScreen.manufacturer), // Placeholder userName
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            Row(
              children: [
                ElevatedButton.icon(
                  onPressed: _showFormDialog,
                  icon: const Icon(Icons.add, size: 18),
                  label: const Text('Add Manufacturer'),
                  style: ElevatedButton.styleFrom(
                    backgroundColor: Colors.purple.shade100,
                    foregroundColor: Colors.black87,
                    padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
                    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: TextField(
                    controller: _searchController,
                    decoration: InputDecoration(
                      hintText: 'Search',
                      hintStyle: TextStyle(color: Colors.grey.shade400),
                      prefixIcon: const Icon(Icons.search),
                      filled: true,
                      fillColor: Colors.white,
                      border: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: BorderSide.none),
                    ),
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),
            Expanded(
              child: RefreshIndicator(
                onRefresh: _fetchManufacturers,
                child: FutureBuilder<List<dynamic>>(
                  future: _manufacturersFuture,
                  builder: (context, snapshot) {
                    if (snapshot.connectionState == ConnectionState.waiting && _allManufacturers.isEmpty) {
                      return const Center(child: CircularProgressIndicator());
                    }
                    if (snapshot.hasError && _allManufacturers.isEmpty) {
                      return Center(child: Text('Error: ${snapshot.error}'));
                    }
                    if (_filteredManufacturers.isEmpty) {
                      return const Center(child: Text('No manufacturers found.'));
                    }

                    return ListView.builder(
                      itemCount: _filteredManufacturers.length,
                      itemBuilder: (context, index) {
                        final manufacturer = _filteredManufacturers[index];
                        final name = manufacturer['manufacturerName'] ?? 'No Name';
                        final id = manufacturer['manufacturerId'];

                        return Padding(
                          padding: const EdgeInsets.only(bottom: 12),
                          child: Slidable(
                            key: Key(id.toString()),
                            endActionPane: ActionPane(
                              motion: const StretchMotion(),
                              children: [
                                SlidableAction(
                                  onPressed: (context) => _showFormDialog(manufacturer: manufacturer),
                                  backgroundColor: Colors.blue,
                                  foregroundColor: Colors.white,
                                  icon: Icons.edit,
                                  label: 'Edit',
                                ),
                                SlidableAction(
                                  onPressed: (context) => _confirmDelete(id, name),
                                  backgroundColor: Colors.red,
                                  foregroundColor: Colors.white,
                                  icon: Icons.delete,
                                  label: 'Delete',
                                  borderRadius: const BorderRadius.horizontal(
                                      right: Radius.circular(16)),
                                ),
                              ],
                            ),
                            child: Card(
                              margin: EdgeInsets.zero,
                              color: Colors.white,
                              elevation: 1,
                              shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(16),
                                side: BorderSide(color: Colors.grey.shade300, width: 1),
                              ),
                              child: ListTile(
                                title: Text(
                                  name,
                                  style: const TextStyle(
                                    fontSize: 16,
                                    fontWeight: FontWeight.w600,
                                    color: Colors.black87,
                                  ),
                                ),
                              ),
                            ),
                          ),
                        );
                      },
                    );
                  },
                ),
              ),
            ),
          ],
        ),
      ),
      bottomNavigationBar: BottomNavBar(
        selectedIndex: _selectedIndex,
        onItemTapped: (index) {
          if (index == 0) {
            Navigator.pop(context);
          } else {
            setState(() {
              _selectedIndex = index;
            });
          }
        },
      ),
    );
  }
}