internal class Program : Utils
    {
        static bool _UserExist(string username)
        {
            Utils tools = new Utils();
            SqlConnection connection = new SqlConnection(tools.ConnectionString);
            SqlCommand command = new SqlCommand
            {
                Connection = connection,
                CommandType = CommandType.Text,
                CommandText = "USE TAO; SELECT * FROM [User] WHERE Username = " + "'" + username + "';"
            };

            try
            {
                connection.Open();
                var reader = command.ExecuteReader();
                if (reader.HasRows)
                    return true;
            }
            catch(Exception ex)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("Error during the creation of the user : " + ex.Message);
            }
            finally
            {
                Console.ForegroundColor = ConsoleColor.Gray;
            }
            return false;
        }

        static void _AddUser()
        {
            MD5CryptoServiceProvider md5Hash = new MD5CryptoServiceProvider();
            List<char> passwordMask = new List<char>();
            Utils tools = new Utils();
            string username = null, password = "";
            SqlConnection connection = new SqlConnection(tools.ConnectionString);
            SqlCommand command = new SqlCommand();

            Console.WriteLine("CreationUserTool\n");
            while (string.IsNullOrEmpty(username))
            {
                Console.Write("Username : ");
                username = Console.ReadLine();
            }
            while (passwordMask.Count == 0 || passwordMask.ToString() == "")
            {
                Console.Write("Password : ");
                ConsoleKeyInfo consoleKeyInfo;
                while ((consoleKeyInfo = Console.ReadKey(true)).Key != ConsoleKey.Enter)
                {
                    if (consoleKeyInfo.Key != ConsoleKey.Backspace)
                    {
                        passwordMask.Add(consoleKeyInfo.KeyChar);
                        Console.Write("*");
                    }
                    else if (passwordMask.Count > 0)
                    {
                        Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
                        Console.Write(" ");
                        Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
                        if (passwordMask.Count > 0)
                            passwordMask.RemoveAt(passwordMask.Count - 1);
                    }
                }
                Console.WriteLine("");
                //password = Console.ReadLine();
            }
            if (_UserExist(username))
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("User already exist");
                Console.ForegroundColor = ConsoleColor.White;
                ConsoleKeyInfo key = Console.ReadKey();
                if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                    return;
            }
            foreach (var item in passwordMask)
            {
                password += item;
            }
            var data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(password));
            md5Hash.Dispose();
            command.Connection = connection;
            command.CommandType = CommandType.Text;
            command.CommandText = "USE TAO; INSERT into [User] (Id, Username, Password) VALUES (@Id, @Username, @Password);";
            command.Parameters.AddWithValue("@Id", Guid.NewGuid());
            command.Parameters.AddWithValue("@Username", username);
            command.Parameters.AddWithValue("@Password", Convert.ToBase64String(data));
            try
            {
                connection.Open();
                command.ExecuteNonQuery();
                Console.ForegroundColor = ConsoleColor.Green;
                Console.WriteLine("User added successfully");
                ConsoleKeyInfo key = Console.ReadKey();
                if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                    return;
            }
            catch (SqlException ex)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("Error during the creation of the user : " + ex.Message);
                ConsoleKeyInfo key = Console.ReadKey();
                if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                    return;
            }
            finally
            {
                Console.ForegroundColor = ConsoleColor.Gray;
            }
        }

        static void _ModifyUser()
        {
            int i, choice;
            string username = null, password = "";
            List<string> users = new List<string>();
            Utils tools = new Utils();
            SqlConnection connection = new SqlConnection(tools.ConnectionString);
            SqlCommand command = new SqlCommand
            {
                Connection = connection,
                CommandType = CommandType.Text,
                CommandText = "SELECT Username FROM [User];"
            };

            try
            {
                connection.Open();
                var reader = command.ExecuteReader();
                while (reader.Read())
                {
                    IDataRecord record = (IDataRecord)reader;
                    users.Add($"{record[0]}");
                }
                reader.Close();
                if (users.Count == 0)
                {
                    Console.WriteLine("ModificationUserTool\n");
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("No user to update");
                    Console.ForegroundColor = ConsoleColor.Gray;
                    ConsoleKeyInfo key = Console.ReadKey();
                    if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                        return;
                }
                while (users.Count > 0)
                {
                    Console.WriteLine("ModificationUserTool\n");
                    Console.WriteLine("Choose user for modification : \n");
                    i = 1;
                    foreach (var user in users)
                    {
                        Console.WriteLine($"\t{i}) {user}");
                        i++;
                    }
                    Console.WriteLine($"\t{i}) Quit\n");
                    Console.Write("Which user : ");
                    if (Int32.TryParse(Console.ReadLine(), out choice))
                    {
                        if (choice - 1 >= 0 && choice - 1 < users.Count)
                        {
                            command.CommandText = "USE TAO; DELETE FROM [User] WHERE Username = '" + users[choice - 1] + "';";
                            command.ExecuteNonQuery();
                            users.RemoveAt(choice - 1);
                            Console.ForegroundColor = ConsoleColor.Green;
                            Console.WriteLine("User deleted successfully");
                            Console.ForegroundColor = ConsoleColor.Gray;
                        }
                        else if (choice - 1 == users.Count)
                        {
                            return;
                        }
                    }
                    Console.Clear();
                }
            }
            catch (Exception ex)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("Error during the creation of the user : " + ex.Message);
                ConsoleKeyInfo key = Console.ReadKey();
                if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                    return;
            }
            finally
            {
                Console.ForegroundColor = ConsoleColor.Gray;
            }
        }

        static void _DeleteUser()
        {
            List<string> users = new List<string>();
            Utils tools = new Utils();
            SqlConnection connection = new SqlConnection(tools.ConnectionString);
            SqlCommand command = new SqlCommand
            {
                Connection = connection,
                CommandType = CommandType.Text,
                CommandText = "SELECT Username FROM [User];"
            };

            try
            {
                connection.Open();
                var reader = command.ExecuteReader();
                while (reader.Read())
                {
                    IDataRecord record = (IDataRecord)reader;
                    users.Add($"{record[0]}");
                }
                reader.Close();
                if (users.Count == 0)
                {
                    Console.WriteLine("ModificationUserTool\n");
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("No users to delete");
                    Console.ForegroundColor = ConsoleColor.Gray;
                    ConsoleKeyInfo key = Console.ReadKey();
                    if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                        return;
                }
                while (users.Count > 0)
                {
                    Console.WriteLine("DeletionUserTool\n");
                    Console.WriteLine("Choose agent for deletion : \n");
                    var i = 1;
                    foreach (var user in users)
                    {
                        Console.WriteLine($"\t{0}) {1}", i, user);
                        i++;
                    }
                    Console.WriteLine($"\t{i}) Quit\n");
                    Console.Write("Which agent : ");
                    int choice;
                    if (Int32.TryParse(Console.ReadLine(), out choice))
                    {
                        if (choice - 1 >= 0 && choice - 1 < users.Count)
                        {
                            command.CommandText = "USE TAO; DELETE FROM [User] WHERE Username = '" + users[choice - 1] + "';";
                            command.ExecuteNonQuery();
                            users.RemoveAt(choice - 1);
                            Console.ForegroundColor = ConsoleColor.Green;
                            Console.WriteLine("User deleted successfully");
                            Console.ForegroundColor = ConsoleColor.Gray;
                        }
                        else if (choice - 1 == users.Count)
                        {
                            return;
                        }
                    }
                    Console.Clear();
                }
            }
            catch (Exception ex)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("Error during the creation of the user : " + ex.Message);
                ConsoleKeyInfo key = Console.ReadKey();
                if (key.Key == ConsoleKey.Enter || key.Key != ConsoleKey.Enter)
                    return;
            }
            finally
            {
                Console.ForegroundColor = ConsoleColor.Gray;
            }
        }

        static void CheckChoice(string choice)
        {
            Console.Clear();
            switch (choice)
            {
                case "1":
                    _AddUser();
                    return;
                case "2":
                    _ModifyUser();
                    return;
                case "3":
                    _DeleteUser();
                    return;
            }
        }

        static void Main(string[] args)
        {
            string choice;
            byte quit = 0;

            while (quit != 1)
            {
                do
                {
                    Console.Clear();
                    Console.WriteLine("Welcome to the UsersManagementTool\n");
                    Console.WriteLine("This tool allows you to :\n");
                    Console.WriteLine("\t1) Create an user.");
                    Console.WriteLine("\t2) Modify an user.");
                    Console.WriteLine("\t3) Delete an user.");
                    Console.WriteLine("\t4) Quit.\n");
                    Console.Write("What do you want ? ");
                    choice = Console.ReadLine();
                } while (choice != "1" && choice != "2" && choice != "3" && choice != "4");
                if (choice == "4")
                    quit = 1;
                else
                    CheckChoice(choice);
            }
        }
    }