using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace ConsoleAdvancedTopics
{
    class RegularExpressionEmail
    {
        // regex101.com  tester
        // regexlib.com  examples and patterns

        // Define the pattern to match
        // ^\w+@[a-zA-Z0-9_]+?\.[a-zA-Z0-9]{2,5}$
        // ^ begins with  $ end string  \w word \d digit[0-9]
        // string pattern = @"^\w+@[a-zA-Z0-9_]+?\.[a-zA-Z0-9]{2,5}$";

        private readonly Regex _emailRegex; // hidden

        public RegularExpressionEmail() // constructor name class name decoratored with a tuple ()
        {
            // define the regex pattern for validation
            string pattern = @"^\w+@[a-zA-Z0-9_]+?\.[a-zA-Z0-9]{2,5}$";

            _emailRegex = new Regex(pattern, RegexOptions.Compiled);

        } // constructor


        public bool IsValidEmail(string email)
        {
            return _emailRegex.IsMatch(email);

        } // IsValidEmail

        // List of test values
        public void ValidateEmails(string[] emails)
        {
        
            foreach (string email in emails)
            {
                bool isValid = IsValidEmail(email);
                Console.WriteLine($"Email: {email} is Valid: {isValid}");
            }
        
        } // ValidateEmails


    } // RegularExpressionEmail
}