import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:cashumit/models/receipt_item.dart';
import 'package:shared_preferences/shared_preferences.dart';

class AddItemScreen extends StatefulWidget {
  const AddItemScreen({super.key, this.item});

  // Constructor untuk mode edit
  const AddItemScreen.fromItem(this.item, {super.key});

  final ReceiptItem? item;

  @override
  State<AddItemScreen> createState() => _AddItemScreenState();
}

class _AddItemScreenState extends State<AddItemScreen> {
  final _formKey = GlobalKey<FormState>();
  late final TextEditingController _descriptionController;
  late final TextEditingController _quantityController;
  late final TextEditingController _priceController;
  final FocusNode _priceFocusNode = FocusNode();

  List<Map<String, dynamic>> _recentItems = [];
  static const String _recentItemsKey = 'recent_receipt_items';

  @override
  void initState() {
    super.initState();

    _descriptionController =
        TextEditingController(text: widget.item?.description ?? '');
    _quantityController = TextEditingController(
        text: widget.item != null
            ? (widget.item!.quantity % 1 == 0
                ? widget.item!.quantity.toInt().toString()
                : widget.item!.quantity.toString())
            : '1');
    _priceController = TextEditingController(
        text: widget.item != null
            ? _formatNumber(widget.item!.price.toInt().toString())
            : '');

    _loadRecentItems();
  }

  @override
  void dispose() {
    _descriptionController.dispose();
    _quantityController.dispose();
    _priceController.dispose();
    _priceFocusNode.dispose();
    super.dispose();
  }

  Future<void> _loadRecentItems() async {
    try {
      final prefs = await SharedPreferences.getInstance();
      final list = prefs.getStringList(_recentItemsKey) ?? [];
      if (list.isNotEmpty && mounted) {
        setState(() {
          _recentItems = list
              .map((e) => jsonDecode(e) as Map<String, dynamic>)
              .take(6)
              .toList();
        });
      }
    } catch (_) {}
  }

  Future<void> _saveRecentItem(String desc, double price) async {
    try {
      final prefs = await SharedPreferences.getInstance();
      final list = prefs.getStringList(_recentItemsKey) ?? [];
      final currentList = list
          .map((e) => jsonDecode(e) as Map<String, dynamic>)
          .where((e) => (e['desc'] as String).toLowerCase() != desc.toLowerCase())
          .toList();

      currentList.insert(0, {'desc': desc, 'price': price});
      final encoded =
          currentList.take(8).map((e) => jsonEncode(e)).toList();
      await prefs.setStringList(_recentItemsKey, encoded);
    } catch (_) {}
  }

  String _formatNumber(String s) {
    final clean = s.replaceAll(RegExp(r'[^\d]'), '');
    if (clean.isEmpty) return '';
    final val = int.tryParse(clean);
    if (val == null) return clean;
    return val.toString().replaceAllMapped(
        RegExp(r'(\d{1,3})(?=(\d{3})+(?!\d))'), (Match m) => '${m[1]}.');
  }

  double _parsePrice(String text) {
    final clean = text.replaceAll('.', '').replaceAll(',', '').trim();
    return double.tryParse(clean) ?? 0.0;
  }

  void _onPriceChanged(String value) {
    final formatted = _formatNumber(value);
    if (formatted != value) {
      _priceController.value = TextEditingValue(
        text: formatted,
        selection: TextSelection.collapsed(offset: formatted.length),
      );
    }
  }

  void _addNominalToPrice(int nominal) {
    final current = _parsePrice(_priceController.text);
    final next = current + nominal;
    final formatted = _formatNumber(next.toInt().toString());
    setState(() {
      _priceController.text = formatted;
    });
  }

  void _stepQuantity(int delta) {
    final current = double.tryParse(_quantityController.text) ?? 1.0;
    final next = current + delta;
    if (next >= 1) {
      setState(() {
        _quantityController.text = next % 1 == 0
            ? next.toInt().toString()
            : next.toString();
      });
    }
  }

  void _selectRecentItem(Map<String, dynamic> item) {
    setState(() {
      _descriptionController.text = item['desc']?.toString() ?? '';
      final price = (item['price'] as num?)?.toDouble() ?? 0.0;
      if (price > 0) {
        _priceController.text = _formatNumber(price.toInt().toString());
      }
    });
    _priceFocusNode.requestFocus();
  }

  void _saveItem() {
    if (_formKey.currentState!.validate()) {
      final desc = _descriptionController.text.trim();
      final qty = double.tryParse(_quantityController.text) ?? 1.0;
      final price = _parsePrice(_priceController.text);

      _saveRecentItem(desc, price);

      final item = ReceiptItem(
        description: desc,
        quantity: qty,
        price: price,
      );

      Navigator.pop(context, item);
    }
  }

  @override
  Widget build(BuildContext context) {
    final primaryColor = Theme.of(context).colorScheme.primary;

    return AlertDialog(
      insetPadding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 24.0),
      title: Row(
        children: [
          Icon(
            widget.item == null ? Icons.add_shopping_cart : Icons.edit_note,
            color: primaryColor,
            size: 22,
          ),
          const SizedBox(width: 8),
          Text(widget.item == null ? 'Tambah Item' : 'Edit Item'),
        ],
      ),
      content: SizedBox(
        width: MediaQuery.of(context).size.width,
        child: SingleChildScrollView(
        child: Form(
          key: _formKey,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              // Kolom Deskripsi Item
              TextFormField(
                controller: _descriptionController,
                autofocus: widget.item == null,
                textInputAction: TextInputAction.next,
                decoration: const InputDecoration(
                  labelText: 'Deskripsi / Nama Item',
                  hintText: 'Misal: Kopi Susu, Nasi Goreng',
                  border: OutlineInputBorder(),
                  isDense: true,
                ),
                validator: (value) {
                  if (value == null || value.trim().isEmpty) {
                    return 'Mohon masukkan nama item';
                  }
                  return null;
                },
                onFieldSubmitted: (_) => _priceFocusNode.requestFocus(),
              ),

              // Saran Item Cepat (Riwayat)
              if (widget.item == null && _recentItems.isNotEmpty) ...[
                const SizedBox(height: 8),
                SingleChildScrollView(
                  scrollDirection: Axis.horizontal,
                  child: Row(
                    children: _recentItems.map((recent) {
                      return Padding(
                        padding: const EdgeInsets.only(right: 6.0),
                        child: ActionChip(
                          avatar: const Icon(Icons.history, size: 13),
                          label: Text(
                            recent['desc']?.toString() ?? '',
                            style: const TextStyle(fontSize: 11),
                          ),
                          onPressed: () => _selectRecentItem(recent),
                          visualDensity: VisualDensity.compact,
                          padding: const EdgeInsets.symmetric(horizontal: 2),
                        ),
                      );
                    }).toList(),
                  ),
                ),
              ],

              const SizedBox(height: 14),

              // Baris Jumlah (dengan stepper) & Harga
              Row(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  // Stepper Jumlah
                  Expanded(
                    flex: 4,
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        const Text(
                          'Jumlah (Qty)',
                          style: TextStyle(fontSize: 12, fontWeight: FontWeight.bold),
                        ),
                        const SizedBox(height: 4),
                        Container(
                          decoration: BoxDecoration(
                            border: Border.all(color: Colors.grey.shade400),
                            borderRadius: BorderRadius.circular(4),
                          ),
                          child: Row(
                            children: [
                              InkWell(
                                onTap: () => _stepQuantity(-1),
                                child: const Padding(
                                  padding: EdgeInsets.symmetric(horizontal: 6, vertical: 8),
                                  child: Icon(Icons.remove, size: 16),
                                ),
                              ),
                              Expanded(
                                child: TextFormField(
                                  controller: _quantityController,
                                  textAlign: TextAlign.center,
                                  decoration: const InputDecoration(
                                    border: InputBorder.none,
                                    isDense: true,
                                    contentPadding: EdgeInsets.zero,
                                  ),
                                  keyboardType: TextInputType.number,
                                  validator: (value) {
                                    if (value == null || value.isEmpty) {
                                      return 'Wajib diisi';
                                    }
                                    if (double.tryParse(value) == null) {
                                      return 'Harus angka';
                                    }
                                    return null;
                                  },
                                ),
                              ),
                              InkWell(
                                onTap: () => _stepQuantity(1),
                                child: const Padding(
                                  padding: EdgeInsets.symmetric(horizontal: 6, vertical: 8),
                                  child: Icon(Icons.add, size: 16),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ],
                    ),
                  ),

                  const SizedBox(width: 12),

                  // Input Harga dengan pemisah ribuan
                  Expanded(
                    flex: 6,
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        const Text(
                          'Harga Satuan',
                          style: TextStyle(fontSize: 12, fontWeight: FontWeight.bold),
                        ),
                        const SizedBox(height: 4),
                        TextFormField(
                          controller: _priceController,
                          focusNode: _priceFocusNode,
                          textInputAction: TextInputAction.done,
                          decoration: const InputDecoration(
                            prefixText: 'Rp ',
                            hintText: '0',
                            border: OutlineInputBorder(),
                            isDense: true,
                          ),
                          keyboardType: TextInputType.number,
                          onChanged: _onPriceChanged,
                          onFieldSubmitted: (_) => _saveItem(),
                          validator: (value) {
                            if (value == null || value.isEmpty) {
                              return 'Mohon masukkan harga';
                            }
                            if (_parsePrice(value) <= 0) {
                              return 'Harga harus > 0';
                            }
                            return null;
                          },
                        ),
                      ],
                    ),
                  ),
                ],
              ),

              const SizedBox(height: 8),

              // Chip Bantuan Nominal Cepat (+5k, +10k, +25k, +50k)
              Wrap(
                spacing: 6,
                children: [
                  ActionChip(
                    label: const Text('+5rb', style: TextStyle(fontSize: 11)),
                    onPressed: () => _addNominalToPrice(5000),
                    visualDensity: VisualDensity.compact,
                  ),
                  ActionChip(
                    label: const Text('+10rb', style: TextStyle(fontSize: 11)),
                    onPressed: () => _addNominalToPrice(10000),
                    visualDensity: VisualDensity.compact,
                  ),
                  ActionChip(
                    label: const Text('+25rb', style: TextStyle(fontSize: 11)),
                    onPressed: () => _addNominalToPrice(25000),
                    visualDensity: VisualDensity.compact,
                  ),
                  ActionChip(
                    label: const Text('+50rb', style: TextStyle(fontSize: 11)),
                    onPressed: () => _addNominalToPrice(50000),
                    visualDensity: VisualDensity.compact,
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(context),
          child: const Text('Batal'),
        ),
        ElevatedButton(
          onPressed: _saveItem,
          child: Text(widget.item == null ? 'Tambah' : 'Simpan'),
        ),
      ],
    );
  }
}