اريد اضافة هنا اسلوب لاضافة رصيد اضافي ان وجد
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:shared_preferences/shared_preferences.dart';

class ThousandsSeparatorInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(
    TextEditingValue oldValue,
    TextEditingValue newValue,
  ) {
    String onlyDigits = newValue.text.replaceAll(RegExp(r'[^0-9]'), '');
    if (onlyDigits.isEmpty) return newValue.copyWith(text: '');

    final buffer = StringBuffer();
    int len = onlyDigits.length;
    for (int i = 0; i < len; i++) {
      buffer.write(onlyDigits[i]);
      int posFromRight = len - i - 1;
      if (posFromRight % 3 == 0 && i != len - 1) buffer.write(',');
    }

    return TextEditingValue(
      text: buffer.toString(),
      selection: TextSelection.collapsed(offset: buffer.length),
    );
  }
}

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

  @override
  State<SplashScreen> createState() => _SplashScreenState();
}

class _SplashScreenState extends State<SplashScreen>
    with TickerProviderStateMixin {
  bool _isLoading = true;
  bool _hasSavedBalance = false;
  int _currentBalance = 0;
  late TextEditingController _balanceController;

  late AnimationController _animationController;
  late Animation<double> _logoScaleAnimation;
  late Animation<Offset> _contentSlideAnimation;
  late Animation<double> _fadeAnimation;

  @override
  void initState() {
    super.initState();
    _balanceController = TextEditingController();

    _animationController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 1000),
    );

    _logoScaleAnimation = Tween<double>(begin: 0.8, end: 1).animate(
      CurvedAnimation(parent: _animationController, curve: Curves.easeOutBack),
    );

    _contentSlideAnimation = Tween<Offset>(
      begin: const Offset(0, 30),
      end: Offset.zero,
    ).animate(
      CurvedAnimation(parent: _animationController, curve: Curves.easeOutQuart),
    );

    _fadeAnimation = Tween<double>(begin: 0, end: 1).animate(
      CurvedAnimation(parent: _animationController, curve: Curves.easeInOut),
    );

    _animationController.forward();
    _loadBalance();
  }

  @override
  void dispose() {
    _balanceController.dispose();
    _animationController.dispose();
    super.dispose();
  }

  Future<void> _loadBalance() async {
    final prefs = await SharedPreferences.getInstance();
    final savedBalance = prefs.getInt('current_balance');

    if (savedBalance != null) {
      _currentBalance = savedBalance;
      _hasSavedBalance = true;
    }

    setState(() {
      _isLoading = false;
      if (_hasSavedBalance) {
        _balanceController.text = _formatWithThousandsSeparator(
          _currentBalance,
        );
      }
    });
  }

  String _formatWithThousandsSeparator(int value) {
    final s = value.toString();
    final buffer = StringBuffer();
    final len = s.length;
    for (int i = 0; i < len; i++) {
      buffer.write(s[i]);
      final posFromRight = len - i - 1;
      if (posFromRight % 3 == 0 && i != len - 1) buffer.write(',');
    }
    return buffer.toString();
  }

  Future<void> _saveBalance(int balance) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt('current_balance', balance);
  }

  void _onContinue() {
    final input = _balanceController.text.replaceAll(',', '').trim();
    final balance = int.tryParse(input);

    if (balance == null || balance < 0) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: const Text('يرجى إدخال مبلغ رصيد صالح (صفر أو أكثر)'),
          behavior: SnackBarBehavior.floating,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(10),
          ),
          backgroundColor: Theme.of(context).colorScheme.error,
        ),
      );
      return;
    }

    _saveBalance(balance).then((_) {
      Navigator.pushReplacementNamed(context, '/home');
    });
  }

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

    return Scaffold(
      backgroundColor: Colors.white,
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
          child:
              _isLoading
                  ? Center(
                    child: CircularProgressIndicator(
                      color: colors.primary,
                      strokeWidth: 2,
                    ),
                  )
                  : Column(
                    children: [
                      Expanded(
                        child: SingleChildScrollView(
                          physics: const BouncingScrollPhysics(),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.center,
                            children: [
                              const SizedBox(height: 40),
                              ScaleTransition(
                                scale: _logoScaleAnimation,
                                child: Container(
                                  width: 120,
                                  height: 120,
                                  decoration: BoxDecoration(
                                    color: colors.primary.withOpacity(0.1),
                                    shape: BoxShape.circle,
                                  ),
                                  child: Icon(
                                    Icons.account_balance_wallet,
                                    size: 60,
                                    color: colors.primary,
                                  ),
                                ),
                              ),
                              const SizedBox(height: 40),
                              SlideTransition(
                                position: _contentSlideAnimation,
                                child: FadeTransition(
                                  opacity: _fadeAnimation,
                                  child: Column(
                                    children: [
                                      Text(
                                        'مرحبًا بك في محول الرصيد',
                                        style: theme.textTheme.headlineSmall
                                            ?.copyWith(
                                              color: Colors.black,
                                              fontWeight: FontWeight.bold,
                                              height: 1.4,
                                            ),
                                        textAlign: TextAlign.center,
                                      ),
                                      const SizedBox(height: 16),
                                      Text(
                                        'أدخل رصيدك الحالي لبدء إدارة وتحويل رصيدك بسهولة',
                                        style: theme.textTheme.bodyLarge
                                            ?.copyWith(
                                              color: Colors.grey[700],
                                              height: 1.6,
                                            ),
                                        textAlign: TextAlign.center,
                                      ),
                                    ],
                                  ),
                                ),
                              ),
                              const SizedBox(height: 40),
                              SlideTransition(
                                position: _contentSlideAnimation,
                                child: FadeTransition(
                                  opacity: _fadeAnimation,
                                  child: TextField(
                                    controller: _balanceController,
                                    keyboardType: TextInputType.number,
                                    inputFormatters: [
                                      ThousandsSeparatorInputFormatter(),
                                    ],
                                    textAlign: TextAlign.right,
                                    style: theme.textTheme.titleMedium
                                        ?.copyWith(fontWeight: FontWeight.w600),
                                    decoration: InputDecoration(
                                      filled: true,
                                      fillColor: Colors.grey[50],
                                      hintText: 'مثال: 1,000',
                                      labelText: 'الرصيد الحالي',
                                      prefixIcon: Icon(
                                        Icons.attach_money_rounded,
                                        color: colors.primary,
                                      ),
                                      border: OutlineInputBorder(
                                        borderRadius: BorderRadius.circular(12),
                                        borderSide: BorderSide(
                                          color: Colors.grey[300]!,
                                        ),
                                      ),
                                      enabledBorder: OutlineInputBorder(
                                        borderRadius: BorderRadius.circular(12),
                                        borderSide: BorderSide(
                                          color: Colors.grey[300]!,
                                        ),
                                      ),
                                      focusedBorder: OutlineInputBorder(
                                        borderRadius: BorderRadius.circular(12),
                                        borderSide: BorderSide(
                                          color: colors.primary,
                                          width: 2,
                                        ),
                                      ),
                                      floatingLabelBehavior:
                                          FloatingLabelBehavior.always,
                                      contentPadding:
                                          const EdgeInsets.symmetric(
                                            horizontal: 20,
                                            vertical: 16,
                                          ),
                                    ),
                                  ),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),
                      const SizedBox(height: 24),
                      SlideTransition(
                        position: _contentSlideAnimation,
                        child: FadeTransition(
                          opacity: _fadeAnimation,
                          child: SizedBox(
                            width: double.infinity,
                            child: ElevatedButton(
                              onPressed: _onContinue,
                              style: ElevatedButton.styleFrom(
                                backgroundColor: colors.primary,
                                foregroundColor: Colors.white,
                                padding: const EdgeInsets.symmetric(
                                  vertical: 16,
                                ),
                                shape: RoundedRectangleBorder(
                                  borderRadius: BorderRadius.circular(12),
                                ),
                                elevation: 0,
                                shadowColor: Colors.transparent,
                              ),
                              child: Text(
                                'ابدأ الآن',
                                style: theme.textTheme.titleMedium?.copyWith(
                                  fontWeight: FontWeight.bold,
                                  color: Colors.white,
                                ),
                              ),
                            ),
                          ),
                        ),
                      ),
                    ],
                  ),
        ),
      ),
    );
  }
}

اعطيني الكود الكامل بعد التعديل لاقوم باستخدامة مباشرة