<?php
/**
 * Yumee Panels - Persistent Background Worker (Foreground Service Equivalent)
 */

require_once __DIR__ . '/db/config.php';

// Prevent multiple instances
$lockFile = __DIR__ . '/worker.lock';
$lock = fopen($lockFile, 'c');
if (!flock($lock, LOCK_EX | LOCK_NB)) {
    die("Worker is already running.\n");
}

function sendTelegramMessage($text) {
    global $pdo; // Assume db() uses a global or similar, let's fetch from settings
    try {
        $stmt = db()->query("SELECT setting_value FROM settings WHERE setting_key = 'telegram_token'");
        $token = $stmt->fetchColumn();
        $stmt = db()->query("SELECT setting_value FROM settings WHERE setting_key = 'telegram_chat_id'");
        $chatId = $stmt->fetchColumn();

        if (!$token || !$chatId) return false;

        $url = "https://api.telegram.org/bot$token/sendMessage";
        $data = [
            'chat_id' => $chatId,
            'text' => "🔔 *Uptime Alert*\n" . $text,
            'parse_mode' => 'Markdown'
        ];
        
        $options = [
            'http' => [
                'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
                'method'  => 'POST',
                'content' => http_build_query($data),
            ],
        ];
        $context  = stream_context_create($options);
        return file_get_contents($url, false, $context);
    } catch (Exception $e) {
        return false;
    }
}

echo "Yumee Panels Background Worker Started (v1.1)...
";

while (true) {
    try {
        $start_time = microtime(true);
        
        // Fetch monitors
        $stmt = db()->query("SELECT * FROM monitors");
        $monitors = $stmt->fetchAll();

        if (!empty($monitors)) {
            $mh = curl_multi_init();
            $handles = [];
            
            foreach ($monitors as $m) {
                $ch = curl_init($m['url']);
                curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
                curl_setopt($ch, CURLOPT_TIMEOUT, 5);
                curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
                curl_setopt($ch, CURLOPT_USERAGENT, 'YumeePinger-Worker/1.1');
                curl_multi_add_handle($mh, $ch);
                $handles[$m['id']] = ['ch' => $ch, 'data' => $m];
            }

            $running = null;
            do {
                curl_multi_exec($mh, $running);
                usleep(5000); 
            } while ($running);

            foreach ($handles as $id => $h) {
                $ch = $h['ch'];
                $m = $h['data'];
                $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
                $latency = round(curl_getinfo($ch, CURLINFO_TOTAL_TIME) * 1000);
                curl_multi_remove_handle($mh, $ch);
                curl_close($ch);

                $is_up = ($http_code >= 200 && $http_code < 400);
                $prev_status = $m['last_status'];
                $prev_notified = $m['last_notified_status'];

                // Update monitor
                $upd = db()->prepare("UPDATE monitors SET last_status = ?, last_latency = ? WHERE id = ?");
                $upd->execute([$http_code, $latency, $id]);

                // Log entry
                $log = db()->prepare("INSERT INTO monitor_logs (monitor_id, status_code, latency) VALUES (?, ?, ?)");
                $log->execute([$id, $http_code, $latency]);

                // Notification logic: only notify on transition
                if ($prev_notified !== null) {
                    $prev_was_up = ($prev_notified >= 200 && $prev_notified < 400);
                    if ($is_up !== $prev_was_up) {
                        $status_str = $is_up ? "✅ UP" : "❌ DOWN";
                        $msg = "Monitor *{$m['name']}* is now $status_str\nURL: {$m['url']}\nStatus: $http_code\nLatency: {$latency}ms";
                        sendTelegramMessage($msg);
                        
                        // Update last notified status
                        $upd_notify = db()->prepare("UPDATE monitors SET last_notified_status = ? WHERE id = ?");
                        $upd_notify->execute([$http_code, $id]);
                    }
                } else {
                    // Initial notification status set
                    $upd_notify = db()->prepare("UPDATE monitors SET last_notified_status = ? WHERE id = ?");
                    $upd_notify->execute([$http_code, $id]);
                }
            }
            curl_multi_close($mh);
        }

        // Record heartbeat in settings for UI to check
        db()->prepare("INSERT INTO settings (setting_key, setting_value) VALUES ('worker_heartbeat', UNIX_TIMESTAMP()) ON DUPLICATE KEY UPDATE setting_value = VALUES(setting_value)")->execute();

        $end_time = microtime(true);
        $execution_time = ($end_time - $start_time);
        $sleep_time = max(0.1, 1 - $execution_time);
        usleep($sleep_time * 1000000);

    } catch (Exception $e) {
        echo "Error: " . $e->getMessage() . "\n";
        sleep(2);
    }
}