Casha/lib/features/add_transaction/provider.dart

import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/constants.dart';
import '../../shared/models/transaction.dart';

class AddTransactionState {
  final double? amount;
  final String category;
  final TransactionType type;
  final DateTime date;
  final String note;
  final bool isSubmitting;
  final String? editingId;

  const AddTransactionState({
    this.amount,
    this.category = 'Food',
    this.type = TransactionType.expense,
    required this.date,
    this.note = '',
    this.isSubmitting = false,
    this.editingId,
  });

  factory AddTransactionState.fromTransaction(Transaction tx) {
    return AddTransactionState(
      amount: tx.amount,
      category: tx.category,
      type: tx.type,
      date: tx.date,
      note: tx.note ?? '',
      editingId: tx.id,
    );
  }

  factory AddTransactionState.empty() {
    return AddTransactionState(date: DateTime.now());
  }

  AddTransactionState copyWith({
    double? amount,
    String? category,
    TransactionType? type,
    DateTime? date,
    String? note,
    bool? isSubmitting,
    String? editingId,
  }) =>
      AddTransactionState(
        amount: amount ?? this.amount,
        category: category ?? this.category,
        type: type ?? this.type,
        date: date ?? this.date,
        note: note ?? this.note,
        isSubmitting: isSubmitting ?? this.isSubmitting,
        editingId: editingId ?? this.editingId,
      );

  bool get isEditing => editingId != null;
}

class AddTransactionNotifier extends StateNotifier<AddTransactionState> {
  AddTransactionNotifier(Transaction? initial)
      : super(initial != null
            ? AddTransactionState.fromTransaction(initial)
            : AddTransactionState.empty());

  void setAmount(double? v) => state = state.copyWith(amount: v);
  
  void setCategory(String v) => state = state.copyWith(category: v);
  
  void setType(TransactionType v) {
    // Reset category to first item of new type
    final newCategory = AppCategories.forType(v).first;
    state = state.copyWith(type: v, category: newCategory);
  }
  
  void setDate(DateTime v) => state = state.copyWith(date: v);
  
  void setNote(String v) => state = state.copyWith(note: v);
  
  void setSubmitting(bool v) => state = state.copyWith(isSubmitting: v);
  
  void reset() => state = AddTransactionState.empty();
}

final addTransactionProvider = StateNotifierProvider.autoDispose
    .family<AddTransactionNotifier, AddTransactionState, Transaction?>(
  (ref, initial) => AddTransactionNotifier(initial),
);

// Reactive categories based on selected type
final availableCategoriesProvider =
    Provider.autoDispose.family<List<String>, Transaction?>((ref, initial) {
  final type = ref.watch(addTransactionProvider(initial).select((s) => s.type));
  return AppCategories.forType(type);
});