<?php

namespace NoccyLabs\Mercureact\Broker;

use SplObjectStorage;

class Topic
{
    const MAX_HISTORY_AGE = 180;

    /** @var string Topic name */
    private string $topic;
    /** @var array<string,Message> */
    private array $messages = [];
    /** @var int Creation unixtime */
    private int $created;

    private SubscriptionList $subscribers;

    public function __construct(string $topic)
    {
        $this->topic = $topic;
        $this->subscribers = new SubscriptionList();
        $this->created = time();
    }

    public function publish(Message $message)
    {
        // TODO check if message id has already been published

        foreach ($this->subscribers as $subscriber) {
            if ($message->private === true) {
                // TODO check subscriber access
            } else {
                // TODO deliver to subscriber
            }
        }
    }

    public function getAge(): int
    {
        return time() - $this->created;
    }

    public function getHistorySize(): int
    {
        return count($this->messages);
    }

    public function getSubscriberCount(): int
    {
        return count($this->subscribers);
    }

    /**
     * Garbage collect histry
     * 
     */
    public function garbageCollect(): void
    {
        $this->messages = array_filter(
            $this->messages,
            fn($message) => $message->getAge() < self::MAX_HISTORY_AGE
        );
    }
}