===== PART 5/12 =====
tiser_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;
                }
            }
        }

        // If no saved campaign or force_new, select a new one
        $CampaignItems = TableRegistry::getTableLocator()->get('CampaignItems');

        // Debug: Log query parameters
        $debug_log = ROOT . DS . 'logs' . DS . 'campaign_debug.log';
        file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [QUERY] Searching campaigns - ad_type: {$ad_type}, traffic_source: {$traffic_source}, country: {$country}\n", FILE_APPEND);

        $campaign_items = $CampaignItems->find()
            ->contain(['Campaigns'])
            ->where([
                'Campaigns.default_campaign' => 0,
                'Campaigns.ad_type' => $ad_type,
                'Campaigns.status' => 1,
                "Campaigns.traffic_source IN (1, :traffic_source)",
                'CampaignItems.weight <=' => 100,
                'CampaignItems.country' => $country,
                'CampaignItems.views < (CampaignItems.purchase * 1000)' // Còn codes chưa dùng hết
            ])
            ->order(['CampaignItems.weight' => 'ASC'])
            ->bind(':traffic_source', $traffic_source, 'integer')
            ->toArray();
        
        file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [QUERY] Query 1 (specific country) - Found: " . count($campaign_items) . " campaigns\n", FILE_APPEND);

        if (count($campaign_items) == 0) {
            $campaign_items = $CampaignItems->find()
                ->contain(['Campaigns'])
                ->where([
                    'Campaigns.default_campaign' => 0,
                    'Campaigns.ad_type' => $ad_type,
                    'Campaigns.status' => 1,
                    "Campaigns.traffic_source IN (1, :traffic_source)",
                    'CampaignItems.weight <=' => 100,
                    'CampaignItems.country' => 'all',
                    'CampaignItems.views < (CampaignItems.purchase * 1000)'
                ])
                ->order(['CampaignItems.weight' => 'ASC'])
                ->bind(':traffic_source', $traffic_source, 'integer')
                ->toArray();
            
            file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [QUERY] Query 2 (country='all') - Found: " . count($campaign_items) . " campaigns\n", FILE_APPEND);
        }

        if (count($campaign_items) == 0) {
            $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.country IN ( 'all', :country)",
                ])
                ->order(['CampaignItems.weight' => 'ASC'])
                ->bind(':traffic_source', $traffic_source, 'integer')
                ->bind(':country', $country, 'string')
                ->limit(50)
                ->toArray();
        }

        // Filter campaigns based on schedule and limits
        $valid_campaign_items = [];
        $current_ip = get_ip();
        $time_zone = get_option('timezone', 'UTC');
        $now = Time::now($time_zone);
        
        file_put_contents($debug_log, "[" . date('Y-m-d H:i:s') . "] [FILTER] Starting filter - Total campaigns to check: " . count($campaign_items) . ", IP: {$current_ip}\n", FILE_APPEND);
        
        foreach ($campaign_items as $item) {
            $campaign = $item->campaign;
            $is_valid = true;
            $reject_reason = '';
            
            // Check start_date
            if (!empty($campaign->start_date)) {
                $start_date = $campaign->start_date->timezone($time_zone);
                if ($now < $start_date) {
                    $is_valid = false;
                    $reject_reason = "Start date not reached (start: {$start_date->format('Y-m-d H:i:s')})";
                }
            }
            
            // 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;
                    $reject_reason = "End date passed (end: {$end_date->format('Y-m-d H:i:s')})";
                }
            }
            
            // 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([