using System;
using System.Data;
using MySql.Data.MySqlClient;

public class Database
{
    private string connectionString = "server=80.90.179.235;database=pozorisp_GorbachevAV;user=pozorisp;password=pozorisp;";

    public MySqlConnection GetConnection()
    {
        return new MySqlConnection(connectionString);
    }

    public bool AuthenticateUser(string username, string password)
    {
        using (var connection = GetConnection())
        {
            connection.Open();
            string query = "SELECT COUNT(*) FROM users WHERE username = @username AND password = @password";
            using (var cmd = new MySqlCommand(query, connection))
            {
                cmd.Parameters.AddWithValue("@username", username);
                cmd.Parameters.AddWithValue("@password", password);
                return Convert.ToInt32(cmd.ExecuteScalar()) > 0;
            }
        }
    }

    public DataTable GetUsers()
    {
        using (var connection = GetConnection())
        {
            connection.Open();
            string query = "SELECT id, username, email FROM users";
            using (var cmd = new MySqlCommand(query, connection))
            using (var adapter = new MySqlDataAdapter(cmd))
            {
                DataTable dt = new DataTable();
                adapter.Fill(dt);
                return dt;
            }
        }
    }

    public void AddUser(string username, string password, string email)
    {
        using (var connection = GetConnection())
        {
            connection.Open();
            string query = "INSERT INTO users (username, password, email) VALUES (@username, @password, @email)";
            using (var cmd = new MySqlCommand(query, connection))
            {
                cmd.Parameters.AddWithValue("@username", username);
                cmd.Parameters.AddWithValue("@password", password);
                cmd.Parameters.AddWithValue("@email", email);
                cmd.ExecuteNonQuery();
            }
        }
    }

    public void UpdateUser(int id, string username, string email)
    {
        using (var connection = GetConnection())
        {
            connection.Open();
            string query = "UPDATE users SET username = @username, email = @email WHERE id = @id";
            using (var cmd = new MySqlCommand(query, connection))
            {
                cmd.Parameters.AddWithValue("@id", id);
                cmd.Parameters.AddWithValue("@username", username);
                cmd.Parameters.AddWithValue("@email", email);
                cmd.ExecuteNonQuery();
            }
        }
    }

    public void DeleteUser(int id)
    {
        using (var connection = GetConnection())
        {
            connection.Open();
            string query = "DELETE FROM users WHERE id = @id";
            using (var cmd = new MySqlCommand(query, connection))
            {
                cmd.Parameters.AddWithValue("@id", id);
                cmd.ExecuteNonQuery();
            }
        }
    }
}