<?php
require_once __DIR__ . '/../db/config.php';

/**
 * Logs an audit event.
 *
 * @param string $action The action performed (e.g., 'login_success', 'credential_create').
 * @param int|null $userId The ID of the user who performed the action. Can be null.
 * @param string|null $targetType The type of object the action was performed on (e.g., 'client', 'credential').
 * @param int|null $targetId The ID of the object.
 */
function log_audit_event(string $action, ?int $userId, ?string $targetType = null, ?int $targetId = null)
{
    try {
        $pdo = db();
        $stmt = $pdo->prepare(
            "INSERT INTO audit_events (user_id, action, target_type, target_id) VALUES (?, ?, ?, ?)"
        );
        $stmt->execute([$userId, $action, $targetType, $targetId]);
    } catch (PDOException $e) {
        // In a real application, you would log this error to a file or monitoring service.
        // For this example, we'll fail silently to not disrupt the user experience.
        error_log('Audit log failed: ' . $e->getMessage());
    }
}
?>