<?php
require_once __DIR__ . '/../includes/bootstrap.php';
$staff = require_staff_login();
header('Content-Type: application/json');

$ticketId = (int)($_GET['ticket_id'] ?? 0);
$action   = $_GET['action'] ?? 'ping';
$pdo      = get_db();

if (!$ticketId) { echo json_encode([]); exit; }

if ($action === 'leave') {
    $pdo->prepare("DELETE FROM ticket_presence WHERE ticket_id=? AND staff_id=?")
        ->execute([$ticketId, $staff['id']]);
    echo json_encode(['ok' => true]);
    exit;
}

if ($action === 'ping') {
    // Eigene Präsenz aktualisieren
    $presenceSql = $pdo->getAttribute(PDO::ATTR_DRIVER_NAME) === 'sqlite'
        ? 'INSERT INTO ticket_presence (ticket_id, staff_id, last_seen_at) VALUES (?,?,?)
           ON CONFLICT(ticket_id, staff_id) DO UPDATE SET last_seen_at=excluded.last_seen_at'
        : 'INSERT INTO ticket_presence (ticket_id, staff_id, last_seen_at) VALUES (?,?,?)
           ON DUPLICATE KEY UPDATE last_seen_at=VALUES(last_seen_at)';
    $pdo->prepare($presenceSql)->execute([$ticketId, $staff['id'], db_now()]);

    // Alte Einträge (> 30 Sek.) löschen
    $pdo->prepare('DELETE FROM ticket_presence WHERE last_seen_at < ?')
        ->execute([date('Y-m-d H:i:s', time() - 30)]);
}

// Alle aktiven Mitarbeiter auf diesem Ticket zurückgeben
$activeSince = date('Y-m-d H:i:s', time() - 30);
$stmt = $pdo->prepare(
    "SELECT s.id, s.name, tp.last_seen_at
     FROM ticket_presence tp
     JOIN staff s ON s.id = tp.staff_id
     WHERE tp.ticket_id = ? AND tp.staff_id != ?
     AND tp.last_seen_at >= ?
     ORDER BY s.name"
);
$stmt->execute([$ticketId, $staff['id'], $activeSince]);
echo json_encode($stmt->fetchAll());