using System;

using System.Collections.Generic;

using System.Globalization;

using Newtonsoft.Json;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        /*

                        string val = "4 Jun 2021";

                var isValid = DateTime.TryParseExact(val, "d MMM yyyy", CultureInfo.CurrentCulture, DateTimeStyles.None, out var dateTime);  

                if (isValid) 

                {

                    Console.WriteLine("YES!");

                }

                else Console.WriteLine("Oh NO!");

        */

            //string[] dates = { "2023-12-31", "2022-04-01", "Jun 1 24", "Jun 2 1924 12:00", "3 Mar 01", "4 Mar 2001", "08 September 1922", "2023-02-01T14:28L28,123Z", "08 September 1922 14:43:31.000" };

            //string[] dates = { "4-5-83", "09-10-98", "4-05-83", @"04-5-83", "2021-04-06 15:53:23.000", "04-06-19 01:40:28.020", "2003-01-01T12:02Z", "Feb 5 12:00", "April 19 1975 12:00", "Jul 14 16 12:00:23.142" };

            string[] dates = { "2000-01-01" };

            foreach (var date in dates)

            {

                //Test(date);

                //continue;

                string dateSlash = date.Replace(@"-", @"/");

                string dateDot = date.Replace(@"-", @".");

                //StandardizeDate(date);

                //continue;

                //StandardizeDate(dateSlash);

                //StandardizeDate(dateDot);

​

                //Console.WriteLine("base=" + date);

​

                Console.WriteLine("in=" + date);

                StandardizeDate(date);

                StandardizeDate(date + " 12:00");

                StandardizeDate(date + " 12:01:02");

                StandardizeDate(date + " 12:03:04.555");

                StandardizeDate(date + " 12:05:06.999-0100");

                StandardizeDate(date + " 12:07:09.333+01:00");

                //StandardizeDate(date + " 12:00:00");

                //StandardizeDate(date + " 12:00:00.000");

                //StandardizeDate(date + " 12:00:00.00000");

​

                /*

                StandardizeDate(date + "T12:00Z");

                StandardizeDate(date + "T12:00:00Z");

                StandardizeDate(date + "T12:00:00.000Z");

                StandardizeDate(date + "T12:00:00.00000Z");

                */

                //StandardizeDate(dateSlash + "T12:00:00Z");

                //StandardizeDate(dateDot + "T12:00:00Z");

​

                //StandardizeDate(dateSlash + "T12:00:00.000Z");

                //StandardizeDate(dateDot + "T12:00:00.000Z");

​

                //StandardizeDate(dateSlash + "T12:00:00.00000Z");

                //StandardizeDate(dateDot + "T12:00:00.00000Z");

                //StandardizeDate(date.Replace(" ", "T") + "Z");

                //StandardizeDate(dateSlash.Replace(" ", "T") + "Z");

                //StandardizeDate(dateDot.Replace(" ", "T") + "Z");

​

            }

    }

​

       private static string StandardizeDate(string indate)

        {

            string indate2 = Regex.Replace(indate, @"\s+", " ").ToLower();

            //Console.WriteLine("standardize indate='" + indate + "'");

            try

            {

                Regex re = new Regex(

                @"(?<datetime>" +

                // Date part

                @"(" +

                    @"(\d{4})\s*[\/\-\.]\s*(\d{1,2})\s*[\/\-\.]\s*(\d{1,2})\s*" +

                    @"|^(\d{1,2}[\/\-\.]\d{1,2}[\/\-\.]\d{4}\s*)" +

                    @"|^(\d{1,2}[\/\-\.]\d{1,2}[\/\-\.]\d{2}\s*)" +

                    //@"|((Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-zA-Z]*\s*\d{1,2},?\s*\d{2}\d{2}?)\s*" +

                    //@"|(((\d{1,2}\s+(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-zA-Z]*,?\s*\d{2}\d{2}?))\s*)" +

                    @"|((Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-zA-Z]*\s*\d{1,2}\s*,?\s*\d{2}(\d{2})?)" +

                    @"|(\d{1,2}\s+(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-zA-Z]*,?\s*\d{2}(\d{2})?)" +

                    @")" +

                    // Optional time part

                    @"(" +

                    @"\s*[Tt]?\s*(\d{2})\s*:\s*(\d{2})\s*:\s*(\d{2})\s*\.\s*(\d{1,3})\s*?[Zz]?" +

                    @"|\s*[Tt]?\s*(\d{2})\s*:\s*(\d{2})\s*:\s*(\d{2})\s*[Zz]?" +

                    @"|\s*[Tt]?\s*(\d{2})\s*:\s*(\d{2})\s*[Zz]?" +

                    @")?" +

                    // Optional offset

                    @"(" +

                    @"([\s*]?[+-]\d{2}:?\d{2})?" +  

                    @")?" +

                    @")", RegexOptions.IgnoreCase); ;

​

                Match match = re.Match(indate2);

                if (match.Success)

                {

                    string mv = match.Value;

                    Console.WriteLine("raw match = " + mv);

                    /*

                    //^\w+(?=\sBrown)

                    string reg = @"(\d{2} \d{2})(?=:\d{2})";

                    Regex x = new Regex(reg);

                    Match m = x.Match(mv);

                    if (m.Success)

                    {

                        Console.WriteLine("MATCHTEST=" + m.Value);

                        string mid = m.Value;

                        string spaceGone = mv.Replace(" ", "ZZZ#delimeter#ZZZ");

                        string allSpacesGone = spaceGone.Replace(" ", string.Empty);                        

                        mv = allSpacesGone.Replace("ZZZ#delimeter#ZZZ", " ");

                    }

                    Console.WriteLine(mv);

                    */

​

                    //string[] formats = { "d MMM yyyy", "MMM dd yyyy HH:mm", "yyyy-MM-dd HH:mm:ss.fff", "yyyy-MM-dd HH:mm", "MMM dd yy HH:mm", "dd MMM yy", "dd MMM yyyy", "dd MMMM yyyy", "dd MMMM yyyy HH:mm", "YYYY-mm-ddtHH:mm:ssz" };

                    //string[] formats = { "yyyy-MM-dd HH:mm:ss.fff", "yyyy-MM-dd HH:mm:ss", "yyyy-MM-dd HH:mm", "yyyy-MM-dd", "dd-MM-yy HH:mm:ss.fff", "dd-MM-yy-HH:mm:ss", "dd-MM-yy HH:mm", "dd-MM-yy" };

                    //string[] formats = { "yyyy-MM-ddTHH:mmZ" };

                    string[] formats = { "yyyy-MM-dd HH:mm:ss.fffzzz", "yyyy-MM-dd HH:mm:ss.fff zzz", "yyyy-MM-dd HH:mm:ss.fff", "yyyy-MM-dd HH:mm:ss", "yyyy-MM-dd HH:mm", "yyyy-MM-dd", "MM-dd-yy HH:mm:ss.fff", "MM-dd-yy HH:mm:ss", "MM-dd-yy HH:mm", "MM-dd-yy", "M-d-yy HH:mm:ss.fff", "M-d-yy HH:mm:ss", "M-d-yy HH:mm", "M-d-yy", "MM-d-yy HH:mm:ss.fff", "MM-d-yy HH:mm:ss", "MM-d-yy HH:mm", "MM-d-yy", "M-dd-yy HH:mm:ss.fff", "M-dd-yy HH:mm:ss", "M-dd-yy HH:mm", "M-dd-yy", "MM-dd-yyyy HH:mm:ss.fff", "MM-dd-yyyy HH:mm:ss", "MM-dd-yyyy HH:mm", "MM-dd-yyyy", "M-d-yyyy HH:mm:ss.fff", "M-d-yyyy HH:mm:ss", "M-d-yyyy HH:mm", "M-d-yyyy", "MM-d-yyyy HH:mm:ss.fff", "MM-d-yyyy HH:mm:ss", "MM-d-yyyy HH:mm", "MM-d-yyyy", "M-dd-yyyy HH:mm:ss.fff", "M-dd-yyyy HH:mm:ss", "M-dd-yyyy HH:mm", "M-dd-yyyy", "MMM dd yyyy HH:mm:ss.fff", "MMM dd yyyy HH:mm:ss", "MMM dd yyyy HH:mm", "MMM d yyyy", "MMM dd yy HH:mm:ss.fff", "MMM dd yy HH:mm:ss", "MMM dd yy HH:mm", "MMM dd yy", "MMMM dd yyyy HH:mm:ss.fff", "MMMM dd yyyy HH:mm:ss", "MMMM dd yyyy HH:mm", "MMMM dd yyyy", "MMMM dd yy HH:mm:ss.fff", "MMMM dd yy HH:mm:ss", "MMMM dd yy HH:mm", "MMMM dd yy", "MMM d yyyy HH:mm:ss.fff", "MMM d yyyy HH:mm:ss", "MMM d yyyy HH:mm", "MMM d yyyy", "MMM d yy HH:mm:ss.fff", "MMM d yy HH:mm:ss", "MMM d yy HH:mm", "MMM d yy", "MMMM d yyyy HH:mm:ss.fff", "MMMM d yyyy HH:mm:ss", "MMMM d yyyy HH:mm", "MMMM d yyyy", "MMMM d yy HH:mm:ss.fff", "MMMM d yy HH:mm:ss", "MMMM d yy HH:mm", "MMMM d yy", "d MMMM yy HH:mm:ss.fff", "d MMMM yy HH:mm:ss", "d MMMM yy HH:mm", "d MMMM yy", "d MMMM yyyy HH:mm:ss.fff", "d MMMM yyyy HH:mm:ss", "d MMMM yyyy HH:mm", "d MMMM yyyy", "dd MMMM yy HH:mm:ss.fff", "dd MMMM yy HH:mm:ss", "dd MMMM yy HH:mm", "dd MMMM yy", "dd MMMM yyyy HH:mm:ss.fff", "dd MMMM yyyy HH:mm:ss", "dd MMMM yyyy HH:mm", "dd MMMM yyyy", "d MMM yy HH:mm:ss.fff", "d MMM yy HH:mm:ss", "d MMM yy HH:mm", "d MMM yy", "d MMM yyyy HH:mm:ss.fff", "d MMM yyyy HH:mm:ss", "d MMM yyyy HH:mm", "d MMM yyyy", "dd MMM yy HH:mm:ss.fff", "dd MMM yy HH:mm:ss", "dd MMM yy HH:mm", "dd MMM yy", "dd MMM yyyy HH:mm:ss.fff", "dd MMM yyyy HH:mm:ss", "dd MMM yyyy HH:mm", "dd MMM yyyy" };

                    //string[] formats = { "MMMM dd yyyy HH:mm:ss.fff", "MMMM dd yyyy HH:mm:ss", "MMMM dd yyyy HH:mm", "MMMM dd yyyy" };

                    //string[] formats = { "yyyy-MM-dd HH:mm:ss.fff" };

                    //if (DateTime.TryParseExact(mv, "yyyy-MM-dd HH:mm:ss.fff", null, DateTimeStyles.None, out var d)) Console.WriteLine("tryparse=" + d.ToString());

                    if (DateTime.TryParseExact(mv, formats, null, DateTimeStyles.None, out var d))

                    {

                        Console.WriteLine("  DATE FORMAT FOUND=" + d.ToString());

                    }

                    else

                    {

                        Console.WriteLine("  FAIL!");

                        //mv = "1900-01-01 00:00:00.000";

                    }

​

​

                    /*

                    string temp = match.Value.ToLower().Replace("z", string.Empty).Replace("t", " ");

                    //string temp = mv.Replace(" ", string.Empty);

                    //Console.WriteLine("adapted=" + temp);

                    if (temp.Contains("augus")) mv = mv.Replace("augus ", "aug");

                    else if (temp.Contains("sep ember ")) mv = mv.Replace("sep ember", "sep");

                    else if (temp.Contains("oc ")) mv = mv.Replace("oc ober", "oct").Replace("oc ", "oct");

                    //if (!mv.Contains("aug") && !mv.Contains("sep") && !mv.Contains("oct")) mv = mv.Replace("t", " ");

                    */

​

                    /*

                    string reg = @"((?<full>(?<one>(-*\s*\d{2}))[ ](?<two>(\d{2}\s:))))";

                    Regex x = new Regex(reg);

                    Match m = x.Match(mv);

                    if (m.Success)

                    {

                        //Console.WriteLine("MATCH");

                        //Console.WriteLine("1='" + m.Groups["one"] + "' 2='" + m.Groups["two"] + "'");

                        string newstr = m.Groups["one"] + "T" + m.Groups["two"];

                        //Console.WriteLine("newstr='" + newstr + "'");

                        //Console.WriteLine("full='" + m.Groups["full"] + "'");

                        mv = mv.Replace(m.Groups["full"].ToString(), newstr).Replace(" ", string.Empty);

                        //Console.WriteLine("new line='" + mv + "'");

                    }

                    */

​

                    Console.WriteLine("    pre-standardize=" + mv);

                    string converted = Convert.ToDateTime(mv).ToString("yyyy-MM-dd HH:mm:ss.fff");

                    Console.WriteLine("      converted=" + converted);

                    //int numspaces = 50 - indate.Length;

                    //Console.WriteLine("in=" + indate + StringSpaces(numspaces) + "out=" + converted);

                    //Console.WriteLine("indate=" + indate + ", indate2=" + indate + ", raw_match=" + rm + ", pre-standardize=" + mv + ", out='" + converted);

                    //if (DateTime.TryParseExact(converted, "yyyy-MM-dd HH:mm:ss.fff", null, DateTimeStyles.None, out var notUsed)) return converted;

                    //else Console.WriteLine("TryParseExact FAILED!");

                }

            }

            catch (Exception ex)

            {

                Console.WriteLine("Exception in StandardizeDate: " + ex.Message);

            }

            int numspaces2 = 50 - "1966-03-31T18:36:13Z".Length;

           // Console.WriteLine("in=" + indate + StringSpaces(numspaces2) + "out=INVALID DATE");

            // Unable to convert to valid date, set to legal date that will fail validation

            return "1966-03-31T18:36:13Z";

        }

}