===== PART 4/12 =====
   }

        return $referer_url;
    }

    protected function getPaidAds($ad_type, $traffic_source, $country, $alias = null, $force_new = false)
    {
        $paidAds = new \stdClass();

        if (get_option('earning_mode', 'campaign') === 'simple') {
            $prices = [];
            if ($ad_type === 1) {
                $prices = get_option('payout_rates_interstitial', []);
                $paidAds->website_url = get_option('interstitial_ad_url', '');
            }

            if ($ad_type === 2) {
                $prices = get_option('payout_rates_banner', []);
                $paidAds->banner_size = '';
                $paidAds->banner_code = '';
            }

            if ($ad_type === 3) {
                $prices = get_option('payout_rates_popup', []);
                $paidAds->website_url = get_option('popup_ad_url', '');
            }

            if ($ad_type === 4) {
                $prices = get_option('payout_rates_traffic', []);
                $paidAds->website_url = '';
            }

            $publisher_price = 0;
            if (!empty($prices[$country][$traffic_source])) {
                $publisher_price = $prices[$country][$traffic_source];
            } elseif (!empty($prices['all'][$traffic_source])) {
                $publisher_price = $prices['all'][$traffic_source];
            }

            $paidAds->mode = 'simple';
            $paidAds->advertiser_price = 0;
            $paidAds->publisher_price = $publisher_price;
            $paidAds->ci = 0;
            $paidAds->cui = 0;
            $paidAds->cii = 0;

            return $paidAds;
        }

        // Check if we have a saved campaign in session and force_new is not set
        $session_key = 'campaign_' . $alias . '_' . $ad_type;
        if (!$force_new && $alias && isset($_SESSION[$session_key])) {
            $saved_cii = $_SESSION[$session_key];
            
            // Try to load the saved campaign
            $CampaignItems = TableRegistry::getTableLocator()->get('CampaignItems');
            $campaign_item = $CampaignItems->find()
                ->contain(['Campaigns'])
                ->where([
                    'CampaignItems.id' => $saved_cii,
                    'CampaignItems.weight <=' => 100,
                    'CampaignItems.views < (CampaignItems.purchase * 1000)',
                    'Campaigns.status' => 1,
                ])
                ->first();
            
            // Validate saved campaign against schedule and limits
            if ($campaign_item) {
                $campaign = $campaign_item->campaign;
                $is_valid = true;
                $current_ip = get_ip();
                $time_zone = get_option('timezone', 'UTC');
                $now = Time::now($time_zone);
                
                // Check start_date
                if (!empty($campaign->start_date)) {
                    $start_date = $campaign->start_date->timezone($time_zone);
                    if ($now < $start_date) {
                        $is_valid = false;
                    }
                }
                
                // Check end_date
                if ($is_valid && !empty($campaign->end_date)) {
                    $end_date = $campaign->end_date->timezone($time_zone);
                    if ($now > $end_date) {
                        $is_valid = false;
                    }
                }
                
                // Check daily_limit (only for traffic campaigns)
                if ($is_valid && $ad_type == 4 && !empty($campaign->daily_limit) && $campaign->daily_limit > 0) {
                    $Statistics = TableRegistry::getTableLocator()->get('Statistics');
                    // Get today's start and end in local timezone, then convert to UTC for database query
                    $today_start_local = Time::now($time_zone)->startOfDay();
                    $today_end_local = Time::now($time_zone)->endOfDay();
                    
                    // Convert to UTC (database stores in UTC)
                    $today_start_utc = $today_start_local->timezone('UTC')->format('Y-m-d H:i:s');
                    $today_end_utc = $today_end_local->timezone('UTC')->format('Y-m-d H:i:s');
                    
                    $today_count = $Statistics->find()
                        ->where([
                            'campaign_id' => $campaign->id,
                            'created >=' => $today_start_utc,
                            'created <=' => $today_end_utc,
                        ])
                        ->count();
                    
                    if ($today_count >= $campaign->daily_limit) {
                        $is_valid = false;
                    }
                }
                
                // 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;
                    }
                }
                
                // If saved campaign is still valid, use it
                if ($is_valid) {
                    $paidAds->mode = 'campaign';
                    $paidAds->adver