import 'package:flutter/material.dart';

/// 应用颜色常量
class AppColors {
  AppColors._();

  static const Color up = Color(0xFF00C853);
  static const Color down = Color(0xFFFF5252);
  static const Color deposit = Color(0xFF00C853);
  static const Color withdraw = Color(0xFFFF9800);
  static const Color trade = Color(0xFF2196F3);

  static const List<Color> gradientColors = [
    Color(0xFF00D4AA),
    Color(0xFF00B894),
  ];
}

/// 表单验证器
class Validators {
  Validators._();

  static String? amount(String? value) {
    if (value == null || value.isEmpty) {
      return '请输入金额';
    }
    final amount = double.tryParse(value);
    if (amount == null || amount <= 0) {
      return '请输入有效金额';
    }
    return null;
  }

  static String? price(String? value) {
    if (value == null || value.isEmpty) {
      return '请输入价格';
    }
    final price = double.tryParse(value);
    if (price == null || price <= 0) {
      return '请输入有效价格';
    }
    return null;
  }

  static String? quantity(String? value) {
    if (value == null || value.isEmpty) {
      return '请输入数量';
    }
    final quantity = double.tryParse(value);
    if (quantity == null || quantity <= 0) {
      return '请输入有效数量';
    }
    return null;
  }

  static String? required(String? value, String fieldName) {
    if (value == null || value.isEmpty) {
      return '请输入$fieldName';
    }
    return null;
  }
}