using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Text.RegularExpressions;

using System.IO;

using System.Globalization;

public class Program

{

​

    //speed optimization

    const string pattern = @"^(?'year'\d{4})(\.|-|\/|\\|\s|\,)*(?'month'0[1-9]|1[1,2])(\.|-|\/|\\|\s|\,)*(?'day'0[1-9]|[12][0-9]|3[01])";

    const RegexOptions options = RegexOptions.Multiline;

    private static readonly Regex myRegex = new Regex(pattern, options);

​

    public static void Main()

    {

        DateTime date; 

        //string input = "2024-04-30-12_20AM-SmokeinBedroom-.JPG";

        string input = "01/31/2024"; 

        //string input = @"2024-04-30";

        //string input = @"2024-30-04";

        //string input = "22-04-2024 -12_20AM-SmokeinBedroom-.JPG";

        string[] dateformats = {"YYYY-MM-DD"}; 

        if ( DateTime.TryParse(input, out date))

            Console.WriteLine(date.ToLongDateString()); 

        else

            Console.WriteLine("Could not convert"); 

        if ( DateTime.TryParseExact(input, dateformats, 

                        System.Globalization.CultureInfo.InvariantCulture,

                        System.Globalization.DateTimeStyles.None, out date))

            Console.WriteLine(date.ToLongDateString()); 

        else

            Console.WriteLine("Could not convert"); 

        try { 

             DateTime dateValue = DateTime.ParseExact(input, "yyyy-MM-dd", System.Globalization.CultureInfo.InvariantCulture); 

             Console.WriteLine("Converted date: " + dateValue); 

        } 

        catch

        { Console.WriteLine("Error: The date is not valid."); }

        try { 

             DateTime dateValue = DateTime.ParseExact(input, "yyyy-dd-MM", System.Globalization.CultureInfo.InvariantCulture); 

             Console.WriteLine("Converted date: " + dateValue); 

        } 

        catch

        { Console.WriteLine("Error: The date is not valid."); }

​

        string input2 = @"2024-04-31-12_20AM-SmokeinBedroom-

2024-31-01-12_20AM-SmokeinBedroom-

30/04/202412_20AM-SmokeinBedroom.jpg

01/31/202412_20AM-SmokeinBedroom.jpg

01-Jan-202212_20AM-SmokeinBedroom.jpg

January 1, 2022 12 20 AM-SmokeinBedroom.jpg";

        string substitution2 = @"${day}-${month}-${year}"; 

​

        MatchCollection mcoll = myRegex.Matches(input2);

        int m = 0;

        Console.WriteLine("mcoll.Count="+mcoll.Count); 

        if (mcoll.Count > 0)

        {

            foreach (Match match in mcoll)

            {

                m++;

                for (int g = 1; g < match.Groups.Count; g++)

                {

                    Console.WriteLine("Match #{0}, Match Value='{1}' Group #{2} -- Index={3}, Value='{4}'", m, match.Value, g, match.Groups[g].Index, match.Groups[g].Value);

                }

​

            }

        }

​

    }

}