<?php
/**
 * staff/ticket_merge_search.php
 * JSON-Endpunkt für die Ticket-Zusammenführen-Suche.
 * Gibt max. 8 Tickets zurück die zur Suchanfrage passen.
 */
require_once __DIR__ . '/../includes/bootstrap.php';
$staff = require_staff_login();
$pdo   = get_db();

header('Content-Type: application/json');

$q       = trim($_GET['q'] ?? '');
$exclude = trim($_GET['exclude'] ?? '');

if (strlen($q) < 2) {
    echo json_encode([]);
    exit;
}

$myDeptIds = staff_department_ids($staff);
$like      = '%' . $q . '%';

// Basis-Query: Ticket suchen (nicht geschlossene und nicht bereits zusammengeführte)
$sql = "SELECT t.ticket_number, t.subject, t.requester_name, t.requester_email,
               t.status, t.created_at,
               p.name AS priority_name,
               d.name AS department_name,
               s.name AS staff_name
        FROM tickets t
        JOIN priorities p ON p.id = t.priority_id
        JOIN departments d ON d.id = t.department_id
        LEFT JOIN staff s ON s.id = t.assigned_staff_id
        WHERE t.merged_into IS NULL
          AND t.status != 'closed'
          AND (t.ticket_number LIKE ? OR t.subject LIKE ? OR t.requester_name LIKE ? OR t.requester_email LIKE ?)";

$params = [$like, $like, $like, $like];

// Ausschluss des aktuellen Tickets
if ($exclude !== '') {
    $sql .= " AND t.ticket_number != ?";
    $params[] = $exclude;
}

// Abteilungsfilter für Nicht-Admins
if ($myDeptIds !== null) {
    $placeholders = implode(',', array_fill(0, count($myDeptIds), '?'));
    $sql .= " AND t.department_id IN ($placeholders)";
    $params = array_merge($params, $myDeptIds);
}

$sql .= " ORDER BY t.updated_at DESC LIMIT 8";

$stmt = $pdo->prepare($sql);
$stmt->execute($params);
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Nur nötige Felder zurückgeben
$out = array_map(fn($t) => [
    'ticket_number'   => $t['ticket_number'],
    'subject'         => $t['subject'],
    'requester_name'  => $t['requester_name'],
    'requester_email' => $t['requester_email'],
    'status'          => $t['status'],
    'priority_name'   => $t['priority_name'],
    'department_name' => $t['department_name'],
    'staff_name'      => $t['staff_name'] ?? '–',
    'created_at'      => $t['created_at'],
], $results);

echo json_encode($out, JSON_UNESCAPED_UNICODE | JSON_HEX_TAG);