<?php
// dezky autodiscover dispatcher. EAS devices and Outlook's mail setup POST
// the same /autodiscover/autodiscover.xml URL but request different response
// schemas — and Z-Push's autodiscover only answers the mobilesync schema
// (it 400s the outlook schema), while Stalwart only serves the mail one.
// So: sniff the request body and route mobilesync to Z-Push, everything
// else to Stalwart unchanged. Deployed into /usr/share/z-push/autodiscover/
// because autodiscover.php resolves its requires relative to that directory.

$body = file_get_contents('php://input');

if (stripos($body, 'autodiscover/mobilesync/responseschema') !== false) {
    chdir(__DIR__);
    require __DIR__ . '/autodiscover.php';
    exit;
}

$upstream = getenv('MAIL_AUTODISCOVER_UPSTREAM');
if ($upstream === false || $upstream === '') {
    http_response_code(502);
    header('Content-Type: text/plain');
    echo "autodiscover upstream not configured\n";
    exit;
}

// Forward the raw Authorization header when present (SetEnvIf in zpush.conf
// exposes it); fall back to rebuilding Basic from mod_php's decoded pair.
$headers = array('Content-Type: ' . ($_SERVER['CONTENT_TYPE'] ?? 'text/xml'));
if (!empty($_SERVER['HTTP_AUTHORIZATION'])) {
    $headers[] = 'Authorization: ' . $_SERVER['HTTP_AUTHORIZATION'];
} elseif (isset($_SERVER['PHP_AUTH_USER'])) {
    $headers[] = 'Authorization: Basic '
        . base64_encode($_SERVER['PHP_AUTH_USER'] . ':' . ($_SERVER['PHP_AUTH_PW'] ?? ''));
}

$ch = curl_init(rtrim($upstream, '/') . '/autodiscover/autodiscover.xml');
curl_setopt_array($ch, array(
    CURLOPT_CUSTOMREQUEST => $_SERVER['REQUEST_METHOD'],
    CURLOPT_POSTFIELDS => $body,
    CURLOPT_HTTPHEADER => $headers,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT => 15,
));
$response = curl_exec($ch);

if ($response === false) {
    http_response_code(502);
    header('Content-Type: text/plain');
    echo "autodiscover upstream unreachable\n";
    curl_close($ch);
    exit;
}

$status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
$contentType = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
curl_close($ch);

http_response_code($status ?: 502);
header('Content-Type: ' . ($contentType ?: 'application/xml'));
echo $response;