<?php
namespace Hpz937\BillReminder\Service;

use Hpz937\BillReminder\Database\DatabaseInterface;
use Hpz937\BillReminder\Model\User;

class UserManager {
    private DatabaseInterface $db;

    public function __construct(DatabaseInterface $db) {
        $this->db = $db;
    }

    public function register(string $username, string $password): bool {
        $passwordHash = password_hash($password, PASSWORD_DEFAULT);

        $sql = "INSERT INTO users (username, passwordHash) VALUES (:username, :passwordHash)";
        $this->db->prepare($sql);
        return $this->db->execute([
            ':username' => $username,
            ':passwordHash' => $passwordHash,
        ]);
    }

    public function login(string $username, string $password): ?User {
        $sql = "SELECT * FROM users WHERE username = :username";
        $this->db->prepare($sql);
        $this->db->execute([':username' => $username]);
        $result = $this->db->fetch();

        if ($result && (new User($result['id'], $result['username'], $result['passwordHash']))->verifyPassword($password)) {
            // Start or regenerate the session
            session_regenerate_id();
            $_SESSION['user_id'] = $result['id'];
            return new User($result['id'], $result['username'], $result['passwordHash']);
        }

        return null;
    }

    // Additional methods as needed, e.g., for password change, user details update, etc.
}