<?php
/*
 * Ready-made search page powered by Polias: a single file, PHP 7.4 or newer, no dependencies.
 * Put it on your web server (e.g. as search.php) and adjust the settings below.
 * Every request with a query costs one search from your Polias credit (check: /api/v1/usage).
 * Your visitors' queries are sent to Polias to answer them: please mention this in your privacy policy.
 * License MIT-0, provided without warranty.
 */

// ---- Settings -----------------------------------------------------------------------------------
$API_KEY        = getenv('POLIAS_API_KEY') ?: 'pol_YOUR_API_KEY'; // your key
$TITLE          = 'Search';      // page heading
$UI_LANGUAGE    = 'en';          // language of this page for your visitors: 'en' or 'de'
$INDEX_LANGUAGE = 'de';          // search index: 'de' (German) or 'en' (English, focus on technical topics)
$TOWN           = '';            // e.g. 'Freiburg im Breisgau': prefer results for this town (German index only)
$OFFICIAL_ONLY  = false;         // true: only results from public authorities and courts (German index only)
$PER_PAGE       = 10;            // results per page, 1 to 10
$MAX_PER_MINUTE = 30;            // at most this many searches per minute through this page (protects against bots)
// -------------------------------------------------------------------------------------------------

$TEXT = [
    'en' => ['placeholder' => 'Enter a search term', 'button' => 'Search', 'none' => 'No results for “%s”.',
             'busy' => 'Too many searches right now. Please try again in a minute.',
             'down' => 'Search is not available right now. Please try again later.',
             'more' => 'More results →', 'credit' => 'Search results by'],
    'de' => ['placeholder' => 'Suchbegriff eingeben', 'button' => 'Suchen', 'none' => 'Keine Treffer für „%s“.',
             'busy' => 'Gerade sind zu viele Suchen auf einmal. Bitte in einer Minute noch einmal versuchen.',
             'down' => 'Die Suche ist gerade nicht erreichbar. Bitte später noch einmal versuchen.',
             'more' => 'Weitere Treffer →', 'credit' => 'Suchergebnisse von'],
][$UI_LANGUAGE] ?? [];

function h($text) { return htmlspecialchars((string) $text, ENT_QUOTES, 'UTF-8'); }

// Counts the searches of the current minute for the whole page (stores nothing about visitors).
function within_limit(int $limit): bool
{
    $file = fopen(sys_get_temp_dir() . '/polias-search-counter', 'c+');
    if (!$file) return true;
    flock($file, LOCK_EX);
    [$minute, $count] = array_map('intval', explode(' ', trim(stream_get_contents($file)) . ' 0 0'));
    $now = (int) (time() / 60);
    $count = $minute === $now ? $count + 1 : 1;
    ftruncate($file, 0);
    rewind($file);
    fwrite($file, "$now $count");
    flock($file, LOCK_UN);
    fclose($file);
    return $count <= $limit;
}

$query = trim(mb_substr((string) ($_GET['q'] ?? ''), 0, 200));
$offset = max(0, min(90, (int) ($_GET['start'] ?? 0)));
$results = [];
$error = '';

if ($query !== '' && !within_limit($MAX_PER_MINUTE)) {
    $error = $TEXT['busy'];
} elseif ($query !== '') {
    $params = ['q' => $query, 'count' => $PER_PAGE, 'offset' => $offset, 'lang' => $INDEX_LANGUAGE];
    if ($TOWN !== '' && $INDEX_LANGUAGE === 'de') $params['ort'] = $TOWN;
    if ($OFFICIAL_ONLY && $INDEX_LANGUAGE === 'de') $params['quelle'] = 'amtlich';
    $context = stream_context_create(['http' => [
        'header' => "Authorization: Bearer $API_KEY\r\n",
        'timeout' => 15,
        'ignore_errors' => true,
    ]]);
    $body = @file_get_contents('https://polias.eu/api/v1/search?' . http_build_query($params), false, $context);
    $status = isset($http_response_header[0]) && preg_match('/\s(\d{3})\s/', $http_response_header[0], $m) ? (int) $m[1] : 0;
    if ($status === 200) {
        $results = json_decode($body, true)['results'] ?? [];
    } elseif ($status === 429) {
        $error = $TEXT['busy'];
    } else {
        $error = $TEXT['down'];
        error_log("Polias search: status $status"); // 401 = wrong key, 402 = credit used up
    }
}
?><!doctype html>
<html lang="<?= h($UI_LANGUAGE) ?>">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <meta name="robots" content="noindex, nofollow">
  <title><?= h($query !== '' ? "$query – $TITLE" : $TITLE) ?></title>
  <style>
    body { font: 17px/1.5 system-ui, sans-serif; max-width: 760px; margin: 0 auto; padding: 24px 16px; color: #1d1d1b; }
    form { display: flex; gap: 8px; margin: 16px 0 24px; }
    input[type=search] { flex: 1; font: inherit; padding: 10px 14px; border: 1px solid #bbb; border-radius: 10px; }
    button { font: inherit; padding: 10px 18px; border: 0; border-radius: 10px; background: #16241a; color: #fff; cursor: pointer; }
    .result { margin: 0 0 22px; }
    .result a { font-size: 19px; color: #1a4fa0; text-decoration: none; }
    .result a:hover { text-decoration: underline; }
    .url { color: #2e6b3a; font-size: 14px; word-break: break-all; }
    .snippet { margin: 2px 0 0; color: #444; }
    .credit { color: #666; font-size: 14px; }
  </style>
</head>
<body>
  <h1><?= h($TITLE) ?></h1>
  <form method="get" role="search">
    <input type="search" name="q" value="<?= h($query) ?>" placeholder="<?= h($TEXT['placeholder']) ?>" maxlength="200" aria-label="<?= h($TEXT['placeholder']) ?>" autofocus>
    <button type="submit"><?= h($TEXT['button']) ?></button>
  </form>

  <?php if ($error !== ''): ?>
    <p><?= h($error) ?></p>
  <?php elseif ($query !== '' && !$results): ?>
    <p><?= h(sprintf($TEXT['none'], $query)) ?></p>
  <?php endif; ?>

  <?php foreach ($results as $r): if (!preg_match('#^https?://#i', $r['url'] ?? '')) continue; ?>
    <div class="result">
      <a href="<?= h($r['url']) ?>" rel="noopener"><?= h($r['title']) ?></a>
      <div class="url"><?= h($r['url']) ?></div>
      <?php if (!empty($r['snippet'])): ?><p class="snippet"><?= h($r['snippet']) ?></p><?php endif; ?>
    </div>
  <?php endforeach; ?>

  <?php if (count($results) === $PER_PAGE && $offset + $PER_PAGE <= 90): ?>
    <p><a href="?<?= h(http_build_query(['q' => $query, 'start' => $offset + $PER_PAGE])) ?>" rel="nofollow"><?= h($TEXT['more']) ?></a></p>
  <?php endif; ?>

  <p class="credit"><?= h($TEXT['credit']) ?> <a href="https://polias.eu">Polias</a></p>
</body>
</html>