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

namespace Dll
{
    public class Class1
    {
        public static List<int> regions = new List<int> { 102, 103, 111, 113, 116, 118, 121, 122, 123, 124, 125, 126, 130, 134, 136, 138, 142, 147, 150, 152, 154, 155, 156, 158, 159, 161, 163, 164, 172, 173, 174, 177, 178, 180, 181, 186, 190, 193, 196, 197, 198, 199, 252, 277, 299, 702, 716, 725, 750, 754, 761, 763, 774, 777, 790, 797, 799, 977 };
        public static List<char> letters = new List<char> { 'A', 'B', 'E', 'K', 'M', 'H', 'O', 'P', 'C', 'T', 'Y', 'X' };

        public static bool CheckMark(string mark)
        {

            if (string.IsNullOrEmpty(mark) || mark.Length != 9)
            {
                throw new ArgumentException("Строка не соответствует формату");
            }

            Regex regex = new Regex(@"^[ABEKMHOPCTYX]{1}\d{3}[ABEKMHOPCTYX]{2}\d{2}(\d{1}|[0-9]{2}|[0-7][0-9]|[8][0-8])$");

            if (regex.IsMatch(mark))
            {
                string regionCode = mark.Substring(6, 3).ToUpper();
                int regionCodeInt = Convert.ToInt32(regionCode);
                if (regions.Contains(regionCodeInt) || (regionCodeInt >= 1 && regionCodeInt <= 99))
                {
                    return true;
                }
            }
            return false;
        }

        public static string GetNextMarkAfter(string mark)
        {
            if (string.IsNullOrEmpty(mark) || mark.Length != 9)
            {
                throw new ArgumentException("Строка не соответствует формату");
            }

            string newMark = mark;
            int number = Convert.ToInt32(mark.Substring(1, 3));
            if(number != 999)
            {
                number++;
                newMark = newMark.Remove(1, 3);
                newMark = newMark.Insert(1,Convert.ToString(number));
            }
            else
            {
                if (newMark[5] != 'X')
                {
                    int index = letters.IndexOf(newMark[5]);
                    newMark = newMark.Remove(5, 1);
                    newMark = newMark.Insert(5, Convert.ToString(letters[index + 1]));
                }
                else if(newMark[4]!= 'X')
                {
                    int index = letters.IndexOf(newMark[4]);
                    newMark = newMark.Remove(4, 1);
                    newMark = newMark.Insert(4, Convert.ToString(letters[index + 1]));
                }
                else if(newMark[0] != 'X')
                {
                    int index = letters.IndexOf(newMark[0]);
                    newMark = newMark.Remove(0, 1);
                    newMark = newMark.Insert(0, Convert.ToString(letters[index + 1]));
                }
                else
                {
                    return "Это конец...";
                }
            }

            return newMark;
        }

        public static string GetNextMarkAfterInRange(string prevMark, string rangeStart, string rangeEnd)
        {
            if (string.IsNullOrEmpty(prevMark) || string.IsNullOrEmpty(rangeStart) || string.IsNullOrEmpty(rangeEnd))
            {
                throw new ArgumentException("Строка не соответствует формату");
            }

            string newMark = prevMark;
            int number = Convert.ToInt32(prevMark.Substring(1, 3));
            int startNumber = Convert.ToInt32(rangeStart.Substring(1, 3));
            int endNumber = Convert.ToInt32(rangeEnd.Substring(1, 3));
            if (number < endNumber && number >= startNumber)
            {
                number++;
                newMark = newMark.Remove(1, 3);
                newMark = newMark.Insert(1, Convert.ToString(number));
                return newMark;
            }
            else
            {
                return "out of stock";
            }
        }

        public static int GetCombinationsCountInRange(string mark1, string mark2)
        {
            if (string.IsNullOrEmpty(mark1) || string.IsNullOrEmpty(mark2))
            {
                throw new ArgumentException("Строка не соответствует формату");
            }

            int startNumber = Convert.ToInt32(mark1.Substring(1, 3));
            int endNumber = Convert.ToInt32(mark2.Substring(1, 3));
            int count = 0;
            while (startNumber <= endNumber)
            {
                count++;
                startNumber++;
            }
            return count;
        }
    }
}