using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;
using MySql.Data.MySqlClient;
namespace login
{

    class Program
    {
        static string connString = "SERVER=shadowdriz.lima-db.de;" +
                                "DATABASE=db_353486_1;" +
                                "UID=USER353486;" +
                                "PASSWORD=censored girl dont even look. XD;";
        static void Main(string[] args)
        {
        A:
            Console.Clear();
            string id, pw, answer;
            Console.Write("id:");
            id = Console.ReadLine();
            Console.Write("pw:");
            pw = ReadPassword();
            if (IsValid(id, pw))
            {
                Console.WriteLine("Successfully Logged in!");
            }
            else
            {
                Console.WriteLine("Wrong Credentials!");
                Console.WriteLine("Do you want to sign up? y/n");
                if ((answer = Console.ReadLine()) == "y")
                    SignUp();
                else
                    goto A;
            }
        }
        static void SignUp()
        {
            Console.Clear();
            Console.Write("id:");
            string id = Console.ReadLine();
            B:
            Console.Write("pw:");
            string pw = ReadPassword();
            Console.Write("pw:");
            string pw2 = ReadPassword();
            if (pw == pw2)
            {
                Console.WriteLine("Signing up..");
                Console.WriteLine("Checking if id is available..");

            }
            else
            {
                Console.WriteLine("Your passwords do not match! Try again!");
                goto B;
            }
        }
        static bool IsValid(string id, string pw)
        {
            using (MySqlConnection conn = new MySqlConnection(connString))
            {
                MySqlCommand cmd = conn.CreateCommand();
                cmd.CommandText = "select password from users where username='@username';";
                conn.Open();
                MySqlDataReader reader = cmd.ExecuteReader();
                while (reader.Read())
                {
                    if (reader.HasRows)
                    {
                        string password = reader.GetString(0);
                        if ((pw = GetMD5(pw)) == password)
                        {
                            return true;
                        }
                    }
                }
                return false;
            }
        }
        static string GetMD5(string text2hash)
        {
            StringBuilder sb = new StringBuilder();
            using (MD5 md5 = MD5.Create())
            {
                byte[] data = md5.ComputeHash(ASCIIEncoding.UTF8.GetBytes(text2hash));
                for (int i = 0; i < data.Length; i++)
                {
                    sb.Append(data[i].ToString("x2"));
                }
            }
            return sb.ToString();
        }
        static string ReadPassword()
        {
            StringBuilder sb = new StringBuilder();
            while (true)
            {
                ConsoleKeyInfo i = Console.ReadKey(true);
                if (i.Key == ConsoleKey.Enter)
                {
                    Console.WriteLine();
                    break;
                }
                if (i.Key == ConsoleKey.Backspace)
                {
                    if (sb.Length > 0)
                    {
                        Console.Write("\b \b");
                        sb.Length--;
                        continue;
                    }
                }
                Console.Write('*');
                sb.Append(i.KeyChar);
            }
            return sb.ToString();
        }
    }
}