<?php

declare(strict_types=1);

namespace App\Domain\Analytics;

final class AnalyticsSessionTransitioner
{
    private const ALLOWED = [
        'open' => ['closed'],
    ];

    public function __construct(private readonly AnalyticsSessionRepository $sessions) {}

    /**
     * Transition a session from open → closed.
     * Silently skips if the session does not exist (e.g. already expired / beacon race).
     *
     * @param  int  $durationSeconds  Wall-clock seconds from started_at to close; caller computes this.
     */
    public function close(string $sessionId, string $exitPath, int $durationSeconds): void
    {
        $session = $this->sessions->findById($sessionId);

        if ($session === null) {
            return;
        }

        $this->guard($session->status, 'closed');

        $this->sessions->close($sessionId, $exitPath, $durationSeconds);
    }

    private function guard(string $from, string $to): void
    {
        $allowed = self::ALLOWED[$from] ?? [];
        if (!in_array($to, $allowed, true)) {
            throw new InvalidTransitionException($from, $to);
        }
    }
}