<?php


class RateLimitRule implements RuleInterface
{
    const MAX_404_REQUESTS = 20; // Allow a maximum of 20 dead links...
    const TIME_WINDOW = 300;     // ...within 300 seconds (5 minutes)

    public function execute()
    {
        $ip = BotLogger::getRealIp();
        if (BotLogger::isWhitelisted($ip)) {
            return true;
        }
        $context = Context::getContext();

        // 1. Instantly skip if this is NOT a 404 error page.
        // During the hookActionFrontControllerInitBefore hook, PrestaShop has already 
        // resolved the route. If it failed, the controller is set to PageNotFoundController.
        if (!($context->controller instanceof PageNotFoundController)) {
            return true;
        }


        // 2. Safely check if the Cache module is installed and enabled
        if (!Module::isInstalled('dbmemorycache') || !Module::isEnabled('dbmemorycache')) {
            return true; // Pass gracefully if the module is missing or disabled
        }

        /** @var DbMemoryCache $cache */
        $cache = Module::getInstanceByName('dbmemorycache');
        if (!$cache) {
            return true;
        }

        // 3. Generate a unique hash for this specific IP's 404 traffic
        $cacheKey = hash('sha256', '404_spam_limiter_' . $ip);

        // 4. Lookup their current 404 hit count in the memory table
        $currentCount = 0;
        if ($cache->existsValue($cacheKey)) {
            $currentCount = (int) $cache->getValue($cacheKey);
        }

        // 5. Increment their strike counter
        $currentCount++;

        // 6. Have they triggered too many 404s?
        if ($currentCount > self::MAX_404_REQUESTS) {

            // Log it so Fail2ban can block them at the server firewall level
            BotLogger::logBan($ip, '404_RATE_LIMIT_EXCEEDED');

            // Drop the connection instantly to save server resources
            header('HTTP/1.1 429 Too Many Requests');
            die('429 Too Many Requests - Stop Scanning');
        }

        // 7. Save the new strike count back to the cache
        // Note: Because we overwrite it here, this creates a "Sliding Window".
        // If a bot keeps spamming, the 300s timer resets every time, keeping them trapped!
        $cache->setValue($cacheKey, $currentCount, self::TIME_WINDOW);

        return true;
    }
}