<?php
declare(strict_types=1);
require_once __DIR__ . '/common.php';

api_require_method('PATCH', 'POST');
$staff = api_require_staff();
$body = api_request_body();
$number = trim((string) ($body['number'] ?? ''));
if ($number === '') {
    api_error(422, 'TICKET_NUMBER_REQUIRED', 'Eine Ticketnummer ist erforderlich.');
}
$pdo = get_db();
$ticket = api_find_ticket($pdo, $staff, $number);
if ($ticket['source'] !== 'chat') {
    $lockedByName = ticket_locked_by_other($ticket, (int) $staff['id'], $pdo);
    if ($lockedByName) {
        api_error(409, 'TICKET_LOCKED', "Dieses Ticket wird gerade von \"$lockedByName\" bearbeitet.");
    }
}
$updates = [];
$params = [];
$now = db_now();
$chatJustClosed = false;

if (array_key_exists('status', $body) && $body['status'] !== $ticket['status']) {
    $status = (string) $body['status'];
    if (!in_array($status, MOBILE_API_STATUSES, true)) {
        api_error(422, 'INVALID_STATUS', 'Der Status ist ungültig.');
    }
    api_require_permission($staff, in_array($status, ['resolved', 'closed'], true) ? 'close_ticket' : 'reply_ticket', (int) $ticket['department_id']);
    $updates[] = 'status = ?';
    $params[] = $status;
    if ($status === 'resolved' && empty($ticket['resolved_at'])) {
        $updates[] = 'resolved_at = ?';
        $params[] = $now;
    }
    if ($status === 'closed' && empty($ticket['closed_at'])) {
        $updates[] = 'closed_at = ?';
        $params[] = $now;
    }
    // Live-Chat, der über die App geschlossen wird, bekommt denselben Chatverlauf-Mail-
    // Versand wie über staff/live_chat.php (Aktion "end") – siehe unten nach dem UPDATE.
    $chatJustClosed = $status === 'closed' && $ticket['source'] === 'chat';
}

if (array_key_exists('assignedStaffId', $body)) {
    $assignedId = $body['assignedStaffId'] === null ? null : filter_var($body['assignedStaffId'], FILTER_VALIDATE_INT);
    if ($assignedId === false) {
        api_error(422, 'INVALID_ASSIGNEE', 'Die Mitarbeiter-ID ist ungültig.');
    }
    if ($assignedId !== null) {
        $agentStmt = $pdo->prepare('SELECT COUNT(*) FROM staff WHERE id = ? AND is_active = 1');
        $agentStmt->execute([$assignedId]);
        if (!(bool) $agentStmt->fetchColumn()) {
            api_error(422, 'INVALID_ASSIGNEE', 'Der ausgewählte Mitarbeiter ist nicht verfügbar.');
        }
    }
    $currentId = $ticket['assigned_staff_id'] === null ? null : (int) $ticket['assigned_staff_id'];
    if ($assignedId !== $currentId) {
        api_require_permission($staff, 'assign_ticket', (int) $ticket['department_id']);
        $updates[] = 'assigned_staff_id = ?';
        $params[] = $assignedId;
    }
}

if (!$updates) {
    api_json(['ticket' => api_ticket_summary($ticket)]);
}
$updates[] = 'updated_at = ?';
$params[] = $now;
$params[] = $ticket['id'];
$pdo->prepare('UPDATE tickets SET ' . implode(', ', $updates) . ' WHERE id = ?')->execute($params);
if (array_key_exists('status', $body) && $body['status'] !== $ticket['status']) {
    [$label] = status_label((string) $body['status']);
    log_activity($pdo, (int) $ticket['id'], (int) $staff['id'], 'Status geändert: ' . $label . ' (Mobile App)');
}
if (array_key_exists('assignedStaffId', $body)) {
    log_activity($pdo, (int) $ticket['id'], (int) $staff['id'], 'Zuweisung geändert (Mobile App)');
}
if ($chatJustClosed && $ticket['requester_email']) {
    try {
        $transcriptStmt = $pdo->prepare(
            'SELECT tt.author_type AS authorType, tt.message, tt.created_at AS createdAt, s.name AS staff_name
             FROM ticket_threads tt LEFT JOIN staff s ON s.id = tt.staff_id
             WHERE tt.ticket_id = ? AND tt.is_internal_note = 0 ORDER BY tt.created_at ASC, tt.id ASC'
        );
        $transcriptStmt->execute([$ticket['id']]);
        $transcriptMessages = array_map(fn(array $m) => [
            'authorType' => $m['authorType'],
            'authorName' => $m['staff_name'],
            'message'    => $m['message'],
            'createdAt'  => $m['createdAt'],
        ], $transcriptStmt->fetchAll());
        notify_customer_chat_transcript($ticket, $transcriptMessages);
    } catch (Throwable $e) {
        error_log('ticket_update (Mobile App) transcript mail: ' . $e->getMessage());
    }
}
$updated = api_find_ticket($pdo, $staff, $number);
if ($updated['status'] !== $ticket['status']) webhook_dispatch($pdo, 'ticket.status_changed', (int) $ticket['id'], ['previousStatus' => $ticket['status']]);
if ((int) ($updated['assigned_staff_id'] ?? 0) !== (int) ($ticket['assigned_staff_id'] ?? 0)) webhook_dispatch($pdo, 'ticket.assigned', (int) $ticket['id']);
api_json(['ticket' => api_ticket_summary($updated)]);