---

package dao;

import db.DatabaseConnection;
import model.User;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.sql.*;

public class UserDAO {

    // Хеширование пароля (SHA-256)
    public static String hashPassword(String password) {
        try {
            MessageDigest md = MessageDigest.getInstance("SHA-256");
            byte[] hash = md.digest(password.getBytes());
            StringBuilder sb = new StringBuilder();
            for (byte b : hash) {
                sb.append(String.format("%02x", b));
            }
            return sb.toString();
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
    }

    // Регистрация
    public boolean register(String username, String email, String password) {
        String sql = "INSERT INTO users (username, email, password_hash) VALUES (?, ?, ?)";
        try (Connection conn = DatabaseConnection.getConnection();
             PreparedStatement stmt = conn.prepareStatement(sql)) {

            stmt.setString(1, username);
            stmt.setString(2, email);
            stmt.setString(3, hashPassword(password));

            return stmt.executeUpdate() > 0;

        } catch (SQLException e) {
            System.err.println("Ошибка регистрации: " + e.getMessage());
            return false;
        }
    }

    // Проверка существования пользователя
    public boolean userExists(String username, String email) {
        String sql = "SELECT 1 FROM users WHERE username = ? OR email = ?";
        try (Connection conn = DatabaseConnection.getConnection();
             PreparedStatement stmt = conn.prepareStatement(sql)) {
            stmt.setString(1, username);
            stmt.setString(2, email);
            try (ResultSet rs = stmt.executeQuery()) {
                return rs.next();
            }
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        }
    }

    // Авторизация
    public User login(String username, String password) {
        String sql = "SELECT id, username, email, password_hash FROM users WHERE username = ?";
        try (Connection conn = DatabaseConnection.getConnection();
             PreparedStatement stmt = conn.prepareStatement(sql)) {

            stmt.setString(1, username);
            try (ResultSet rs = stmt.executeQuery()) {
                if (rs.next()) {
                    String storedHash = rs.getString("password_hash");
                    if (storedHash.equals(hashPassword(password))) {
                        return new User(
                            rs.getInt("id"),
                            rs.getString("username"),
                            rs.getString("email"),
                            storedHash
                        );
                    }
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}