using System.Text.RegularExpressions;

namespace Common.Utils
{
    public static class ValidationHelper
    {
        private static readonly Regex MobileRegex = new(@"^1[3-9]\d{9}$", RegexOptions.Compiled);

        private static readonly Regex IdCardRegex = new(@"^[1-9]\d{5}(19|20)\d{2}(0[1-9]|1[0-2])(0[1-9]|[12]\d|3[01])\d{3}[\dXx]$", RegexOptions.Compiled);

        private static readonly Regex UserNameRegex = new(@"^[\u4e00-\u9fa5a-zA-Z0-9_]{2,20}$", RegexOptions.Compiled);

        public static bool IsValidMobile(string mobile)
        {
            if (string.IsNullOrWhiteSpace(mobile))
                return false;
            return MobileRegex.IsMatch(mobile);
        }

        public static bool IsValidIdCard(string idCard)
        {
            if (string.IsNullOrWhiteSpace(idCard) || idCard.Length != 18)
                return false;

            if (!IdCardRegex.IsMatch(idCard))
                return false;

            return ValidateIdCardCheckSum(idCard);
        }

        public static bool IsValidUserName(string userName)
        {
            if (string.IsNullOrWhiteSpace(userName))
                return false;
            return UserNameRegex.IsMatch(userName);
        }

        public static bool IsPositiveAmount(long amount)
        {
            return amount > 0;
        }

        public static bool IsPositiveAmount(int amount)
        {
            return amount > 0;
        }

        public static bool IsInRange(int count, int min, int max)
        {
            return count >= min && count <= max;
        }

        public static bool IsValidLength(string value, int minLength, int maxLength)
        {
            if (string.IsNullOrWhiteSpace(value))
                return false;
            return value.Length >= minLength && value.Length <= maxLength;
        }

        public static bool IsValidPassword(string password)
        {
            if (string.IsNullOrWhiteSpace(password) || password.Length < 6 || password.Length > 20)
                return false;
            return password.Any(char.IsLetter) && password.Any(char.IsDigit);
        }

        private static bool ValidateIdCardCheckSum(string idCard)
        {
            int[] weight = { 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2 };
            char[] checkCodes = { '1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2' };

            int sum = 0;
            for (int i = 0; i < 17; i++)
            {
                sum += (idCard[i] - '0') * weight[i];
            }

            char expectedCheckChar = checkCodes[sum % 11];
            char actualCheckChar = char.ToUpper(idCard[17]);

            return expectedCheckChar == actualCheckChar;
        }
    }
}