using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.Text.RegularExpressions;

namespace Neo.Afx.Validation
{
    /// <summary>
    /// The formatter.
    /// </summary>
    public class RsaTrustNumberValidation
    {
        /// <summary>
        /// Does check digit validation on an RSA Company Registration Number
        /// </summary>
        /// <param name="companyRegNumber">The Company Registration Number.</param>
        /// <returns>True/False</returns>
        [SqlFunction(
            IsDeterministic = true,
            IsPrecise = true,
            DataAccess = DataAccessKind.Read,
            SystemDataAccess = SystemDataAccessKind.Read
            )]
        public static SqlBoolean IsValidRsaTrustNumber(SqlString trustNumber)
        {
            var isValid = false;
            var trustNumberToCheck = trustNumber.Value;

            if (string.IsNullOrEmpty(trustNumberToCheck))
            { 
                return  new SqlBoolean(isValid);
            }

            Regex rgx = new Regex(@"^\d{4}\/\d{6}\/\d{2}$");
            if (rgx.IsMatch(trustNumberToCheck))
            {
                isValid = true;
            }

            return new SqlBoolean(isValid);
        }
    }
}