using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PhilExampleCrawler.Common.Models
{
    public static class Validator
    {
        private const string ALLOWED = "0123456789";

        /// <summary> Removes any character that is not contained in "0123456789" </summary>
        public static string PhoneNumber_Normalize(this string phone)
        {
            if (string.IsNullOrEmpty(phone))
                return "";

            string p = "";
            for (int i = phone.Length - 1; i >= 0; i--)
                if (ALLOWED.Any(c => c == phone[i]))
                    p = phone[i] + p;
            return p;
            //=> phone.Trim().TrimStart('+').TrimStart('0')
        }
    }
}