namespace CSLight
{
    public class Program
    {
        private static object cw;

        static void Main(string[] args)
        {
            string[] listEmployees = new string[0];
            string[] positions = new string[0];
            bool canWork = true;

            const string FillingDossierCommand = "1";
            const string ShowAllDossierCommand = "2";
            const string SearchLastnameCommand = "3";
            const string DeleteDossierCommand = "4";
            const string ExitProgrammCommand = "5";

            while (canWork)
            {
                Console.WriteLine(
                $"{FillingDossierCommand})Добавить досье\n" +
                $"{ShowAllDossierCommand})Вывести все досье\n" +
                $"{SearchLastnameCommand})Поиск по фамилии\n" +
                $"{DeleteDossierCommand})Удалить досье\n" +
                $"{ExitProgrammCommand})Выход из программы\n");

                switch (Console.ReadLine())
                {
                    case FillingDossierCommand:
                        FillDossier(ref listEmployees, ref positions);
                        break;

                    case ShowAllDossierCommand:
                        ShowAllDossier(listEmployees, positions);
                        break;

                    case SearchLastnameCommand:
                        SearchLastname(listEmployees);
                        break;

                    case DeleteDossierCommand:
                        DeleteDossier(ref listEmployees, ref positions);
                        break;

                    case ExitProgrammCommand:
                        canWork = false;
                        break;
                }

            }

        }

        static void FillDossier(ref string[] listEmployees, ref string[] positions)
        {
            Console.WriteLine("Введите ФИО сотрудинка через пробел.");
            string fullName = Console.ReadLine();
            Console.WriteLine("Введите должность сотрудинка через пробел.");
            string post = Console.ReadLine();

            ExpandArray(listEmployees, fullName);
            ExpandArray(positions, post);
        }

        static void ShowAllDossier(string[] listEmployees, string[] positions)
        {
            for (int i = 0; i < listEmployees.Length; i++)
            {
                Console.WriteLine($"{i + 1}){listEmployees[i]}-{positions[i]}");
            }

            Console.ReadKey();
        }

        static void SearchLastname(string[] array)
        {
            Console.WriteLine("Введите нужную фамилию для поиска");
            string lastName = Console.ReadLine();

            Console.WriteLine($"Сотрудники с фамилией '{lastName}':");

            foreach (var worker in array)
            {
                if (worker.StartsWith(lastName, StringComparison.OrdinalIgnoreCase))
                {
                    Console.WriteLine(worker);
                }
            }
        }

        static void DeleteDossier(ref string[] listEmployees, ref string[] positions)
        {
            ShowAllDossier(listEmployees, positions);

            Console.WriteLine("Введите номер досье которое хотите удалить.");
            int number = ReadInt();

            DeleteArrayElement(listEmployees, number);
            DeleteArrayElement(positions, number);
        }

        static string[] ExpandArray(string[] array, string word)
        {
            string[] temporaryArray = new string[array.Length + 1];

            for (int i = 0; i < array.Length; i++)
            {
                temporaryArray[i] = array[i];
            }

            temporaryArray[temporaryArray.Length - 1] = word;

            array = temporaryArray;

            return array;
        }

        static string[] DeleteArrayElement(string[] array, int number)
        {
            string[] temporaryArray = new string[array.Length - 1];
            string dossier = array[number - 1];
            int index = 0;

            foreach (var item in array)
            {
                if (item != dossier)
                {
                    temporaryArray[index++] = item;
                }
            }

            array = temporaryArray;

            return array;
        }

        static int ReadInt()
        {
            int number = 0;

            while (int.TryParse(Console.ReadLine(), out number) == false)
            {
                Console.WriteLine("Это не число.");
            }

            return number;
        }
    }
}