===== PART 6/12 =====
                'campaign_id' => $campaign->id,
                        'created >=' => $today_start_utc,
                        'created <=' => $today_end_utc,
                    ])
                    ->count();
                
                if ($today_count >= $campaign->daily_limit) {
                    $is_valid = false;
                    $reject_reason = "Daily limit exceeded (count: {$today_count}, limit: {$campaign->daily_limit})";
                }
            }
            
            // Check ip_limit (only for traffic campaigns - count from start of today)
            if ($is_valid && $ad_type == 4 && !empty($campaign->ip_limit) && $campaign->ip_limit > 0) {
                $Statistics = TableRegistry::getTableLocator()->get('Statistics');
                // Count from start of today (same logic as daily_limit)
                $today_start_local = Time::now($time_zone)->startOfDay();
                $today_start_utc = $today_start_local->timezone('UTC')->format('Y-m-d H:i:s');
                
                $ip_count = $Statistics->find()
                    ->where([
                        'campaign_id' => $campaign->id,
                        'ip' => $current_ip,
                        'created >=' => $today_start_utc,
                    ])
                    ->count();
                
                if ($ip_count >= $campaign->ip_limit) {
                    $is_valid = false;
                    $reject_reason = "IP limit exceeded (count: {$ip_count}, limit: {$campaign->ip_limit})";
                }
            }
            
            // Log result
            if ($is_valid) {
                file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [FILTER] Campaign #{$campaign->id} ({$campaign->name}) - ACCEPTED\n", FILE_APPEND);
                $valid_campaign_items[] = $item;
            } else {
                file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [FILTER] Campaign #{$campaign->id} ({$campaign->name}) - REJECTED: {$reject_reason}\n", FILE_APPEND);
            }
        }
        
        file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [FILTER] Filter complete - Valid campaigns: " . count($valid_campaign_items) . "\n", FILE_APPEND);
        
        // If no valid campaigns found, return to default campaigns
        if (count($valid_campaign_items) == 0) {
            // Try to get default campaigns as fallback
            $campaign_items = $CampaignItems->find()
                ->contain(['Campaigns'])
                ->where([
                    'Campaigns.default_campaign' => 1,
                    'Campaigns.ad_type' => $ad_type,
                    'Campaigns.status' => 1,
                    "Campaigns.traffic_source IN (1, :traffic_source)",
                    'CampaignItems.weight <=' => 100,
                    'CampaignItems.views < (CampaignItems.purchase * 1000)',
                    "CampaignItems.country IN ( 'all', :country)",
                ])
                ->order(['CampaignItems.weight' => 'ASC'])
                ->bind(':traffic_source', $traffic_source, 'integer')
                ->bind(':country', $country, 'string')
                ->toArray();
            
            file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [QUERY] Query 3 (default campaigns) - Found: " . count($campaign_items) . " campaigns\n", FILE_APPEND);
            
            $valid_campaign_items = $campaign_items;
        }

        // If still no valid campaigns found (all exceeded limits), return empty
        if (count($valid_campaign_items) == 0) {
            file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [RESULT] No valid campaigns available\n", FILE_APPEND);
            
            // Return empty paidAds to indicate no campaign available
            $paidAds->mode = 'simple';
            $paidAds->advertiser_price = 0;
            $paidAds->publisher_price = 0;
            $paidAds->ci = 0;
            $paidAds->cui = 0;
            $paidAds->cii = 0;
            $paidAds->website_url = '';
            $paidAds->banner_size = '';
            $paidAds->banner_code = '';
            $paidAds->content = '';
            
            return $paidAds;
        }

        shuffle($valid_campaign_items);

        $campaign_item = array_values($valid_campaign_items)[0];

        // Save campaign to session
        if ($alias) {
            $_SESSION[$session_key] = $campaign_item->id;
        }

        $paidAds->mode = 'campaign';
        $paidAds->advertiser_price = $campaign_item->advertiser_price;
        $paidAds->publisher_price = $campaign_item->publisher_price;
        $paidAds->ci = $campaign_item->campaign_id;
        $paidAds->cui = $campaign_item->campaign->user_id;
        $paidAds->cii = $campaign_item->id;
        $paidAds->website_url = $campaign_item->campaign->website_url;
        $paidAds->banner_size = $campaign_item->campaign->banner_size;
        $paidAds->banner_code = $campaign_item->campaign->banner_code;
        $paidAds->content = $campaign_item->campaign->content ?? '';

        return $paidAds;
    }

    /**
     * @param array|object $data
     * @param \App\Model\Entity\Link $link
     * @param int $ad_type
     * @return array
     */
    protected function calcEarnings($data, $link, $ad_type)
    {
        /**
         * Views reasons
         * 1- Earn
         * 2- Disabled cookie
         * 3- Anonymous user
         * 4- Adblock
         * 5- Proxy
         * 6- IP changed
         * 7- Not unique
         * 8- Full weight
         * 9- Default campaign
         * 10- Direct
         * 11- Invalid Country
         * 12- Earnings disabled
         * 13- User disabled earnings
         * 14- Blocked referer
         * 15- Hourly limit reached
         * 16- Daily limit reached
         * 17- Monthly limit reached
         * 18- Campaign daily limit reached (race condition check)
         * 19- Campaign IP limit reached (race condition check)