/', '', $html); $html = preg_replace('/<\/code><\/pre>$/', '', $html);
  $html = str_replace('
', "\n", $html);
  $out = []; $open = null;
  foreach (explode("\n", $html) as $line) {
    $line = rtrim($line, "\r");
    $pre = $open !== null ? '' : '';
    $count = preg_match_all('//', $line, $m, PREG_OFFSET_CAPTURE); $closes = substr_count($line, '');
    if ($count > $closes) { $open = $m[1][$count - 1][0]; $line .= ''; }
    elseif ($count < $closes) { $open = null; }
    $out[] = $pre.$line;
  }
  return $out;
}
function code_ver_link(string $v, string $f = '', array $extra = []): string {
  $q = ['p' => 'code', 'v' => $v]; if ($f !== '') { $q['f'] = $f; } return 'index.php?'.http_build_query($q + $extra);
}

code_rate_limit();
$snapRoot = __DIR__.'/../inc/snapshots';
$versions = code_versions($snapRoot);
$current = is_file("$snapRoot/current.json") ? (json_decode((string)file_get_contents("$snapRoot/current.json"), true) ?: []) : [];
$v = (string)($_GET['v'] ?? '');
if ($v !== '' && !in_array($v, $versions, true)) { http_response_code(404); page_header('Code', 'code'); echo '
Code
No such version. Current snapshot.
'; page_footer(); exit; }
if ($v === '') { $v = (string)($current['version'] ?? ($versions[0] ?? '')); }
if ($v === '') { page_header('Code', 'code'); echo '
Code
No snapshot has been written yet; the next deploy writes the first one.
'.CODE_STATEMENT.'
'; page_footer(); exit; }
$manifest = json_decode((string)file_get_contents("$snapRoot/$v/code-manifest.json"), true) ?: ['files' => []];
$byPath = []; foreach ($manifest['files'] as $e) { $byPath[$e['path']] = $e; }
$isCurrent = $v === ($current['version'] ?? '');

/* the manifest itself */
if (!empty($_GET['manifest'])) {
  header('Content-Type: application/json; charset=utf-8'); header('Content-Disposition: attachment; filename="code-manifest-'.$v.'.json"'); header('X-Content-Type-Options: nosniff');
  readfile("$snapRoot/$v/code-manifest.json"); exit;
}

/* one file */
$f = (string)($_GET['f'] ?? '');
if ($f !== '') {
  if (!isset($byPath[$f])) { http_response_code(404); page_header('Code', 'code'); echo '
Code
No such file in snapshot '.h($v).'. Back to the tree.
'; page_footer(); exit; }
  $e = $byPath[$f];
  $fn = (string)($_GET['fn'] ?? '');
  if ($fn !== '') {
    if (isset($e['functions'][$fn])) { [$a, $b] = $e['functions'][$fn]; header('Location: '.code_ver_link($v, $f, ['from' => max(1, intdiv($a - 1, CODE_MAX_LINES) * CODE_MAX_LINES + 1)]).'#L'.$a.'-L'.$b); exit; }
    header('Location: '.code_ver_link($v, $f)); exit;
  }
  $src = (string)file_get_contents("$snapRoot/$v/$f");
  if (!empty($_GET['raw'])) { header('Content-Type: text/plain; charset=utf-8'); header('X-Content-Type-Options: nosniff'); header('Content-Disposition: inline; filename="'.basename($f).'.txt"'); echo $src; exit; }
  $lines = code_lines($src, strtolower(pathinfo($f, PATHINFO_EXTENSION)));
  $total = count($lines);
  $from = max(1, (int)($_GET['from'] ?? 1)); $from = min($from, $total); $to = min($total, $from + CODE_MAX_LINES - 1);
  page_header('Code · '.$f, 'code');
  echo '
'.h($f).'
Snapshot '.h($v).''.($isCurrent ? ' (current)' : ' (an earlier version; current)').' · '.(int)$e['lines'].' lines · '.number_format((int)$e['bytes']).' bytes · tree · plain text
';
  echo '
SHA-256 '.h($e['sha256']).'
';
  if (!empty($e['functions'])) { echo '
Functions: '; $i = 0; foreach ($e['functions'] as $name => [$a, $b]) { echo ($i++ ? ' · ' : '').''.h($name).' L'.$a.'-L'.$b.''; } echo '
'; }
  if ($total > CODE_MAX_LINES) {
    echo '
Pages: ';
    for ($s = 1; $s <= $total; $s += CODE_MAX_LINES) { echo 'L'.$s.'-L'.min($total, $s + CODE_MAX_LINES - 1).' '; }
    echo '
';
  }
  echo '
';
  for ($n = $from; $n <= $to; $n++) { echo ''; }
  echo '
'.$n.'
'.($lines[$n - 1] === '' ? ' ' : $lines[$n - 1]).'
';
  echo '
Lines can be cited as '.h($f).' L120-L140, platform code '.h($v).'; add #L120-L140 to this page\'s address to highlight them. '.CODE_STATEMENT.'
';
  echo '';
  page_footer(); exit;
}

/* search */
$q = trim((string)($_GET['q'] ?? ''));
if ($q !== '') {
  page_header('Code · search', 'code');
  echo '
Search the code
';
  echo '
TEXT
Search
';
  if (mb_strlen($q) < 3) { echo '
Three characters at least.
'; page_footer(); exit; }
  $hits = 0; $needle = mb_strtolower(mb_substr($q, 0, 80));
  echo '
Snapshot '.h($v).', file names and contents, case-insensitive.
';
  foreach ($byPath as $path => $e) {
    if (mb_strpos(mb_strtolower($path), $needle) !== false) { echo ''; if (++$hits >= CODE_MAX_HITS) { break; } }
    foreach (explode("\n", (string)file_get_contents("$snapRoot/$v/$path")) as $i => $line) {
      if (mb_strpos(mb_strtolower($line), $needle) === false) { continue; }
      $n = $i + 1; $snip = trim($line); if (mb_strlen($snip) > 160) { $pos = max(0, mb_strpos(mb_strtolower($snip), $needle) - 60); $snip = ($pos ? '…' : '').mb_substr($snip, $pos, 160).'…'; }
      echo '';
      if (++$hits >= CODE_MAX_HITS) { break 2; }
    }
  }
  echo '
File
Line
Text
'.h($path).'
file name
'.h($path).'
'.$n.'
'.h($snip).'
'.($hits === 0 ? 'Nothing found.' : ($hits >= CODE_MAX_HITS ? 'The first '.CODE_MAX_HITS.' matches are shown; narrow the search for the rest.' : $hits.' match'.($hits === 1 ? '' : 'es').'.')).'
';
  page_footer(); exit;
}

/* the tree */
page_header('Code', 'code');
echo '
Code
The Research Labs platform as it runs, shown for scrutiny: every file that reads an instrument, computes a stream, aggregates, checks provenance or renders a page, with a checksum per file. A reader of any published number can open the code that produced it.
';
echo '
Version stamp
'.h($v).'
'.($isCurrent ? 'current snapshot' : 'an earlier version; current').' · written '.h(str_replace('T', ' ', substr((string)($manifest['generated_at'] ?? ''), 0, 19))).' UTC · '.count($byPath).' files · commit: '.h((string)($manifest['commit'] ?? 'not from git')).'
';
echo '
tree SHA-256 '.h((string)($manifest['tree_sha256'] ?? '')).'
manifest SHA-256 '.h((string)($manifest['manifest_sha256'] ?? '')).' · code-manifest.json (also printed on the Raw Vault)
';
echo '
redaction: '.(!empty($manifest['redaction']['ran']) ? 'ran, '.(int)($manifest['redaction']['emails_redacted'] ?? 0).' e-mail address'.((int)($manifest['redaction']['emails_redacted'] ?? 0) === 1 ? '' : 'es').' redacted, secret scan '.h((string)($manifest['redaction']['secret_scan'] ?? '')) : 'not recorded').'
';
if (count($versions) > 1) { echo '
Versions: '; foreach ($versions as $ov) { echo ''.h($ov).' '; } echo '
'; }
echo '
';
echo '
SEARCH THE TREE
Search
';

echo '
How this platform is built
';
echo '
Stack. PHP 8 and MySQL 8 behind Apache, written for this platform without a framework. Charts are dependency-free SVG drawn by assets/app.js. No third-party library is part of the tree; the one outside service is the Anthropic API, called from inc/ai.php for the Ask Grímnir page with a key held in the excluded configuration file.
';
echo '
From instrument to published table. cron/poll_all.php runs on a schedule and calls one client per instrument family under cron/clients/ (weather station, water-quality sonde, aquifer logger, sky quality meter, footfall counters, acoustic recorders). Each pull is stored as a raw file, checksummed and listed in files_raw (the Raw Vault), then parsed into readings rows: stream, timestamp, value, and a placeholder flag. Every stream starts in placeholder mode and flips to live with its first real reading; cron/health_check.php watches freshness and completeness. Pages under pages/ render the readings through inc/streampage.php and inc/helpers.php (series, latest, mode badges); api.php serves the same readings to keyed clients. schema.sql defines the tables.
';
echo '
Excluded, and why. config.php and its template (credentials); data/ (raw files, uploads, media); logs; admin/ (the write path, no part of how a published number is produced); diagnose.php (server layout); the snapshots themselves. Paths are shown relative to the application root. E-mail addresses other than the company\'s are redacted at snapshot time, and a scan for secret-like strings refuses to publish a snapshot that contains one; the allowlist and the snapshot script are in the tree (inc/code-allowlist.php, inc/code-snapshot.php).
';
echo '
Versions. A snapshot is written at each deploy. The version is the UTC date plus seven characters of the tree\'s SHA-256, so an unchanged tree keeps its version and a changed one cannot hide. Every version stays reachable by its stamp, every page footer prints the version that rendered it, and a citation reads: file, lines, platform code version.
';
echo '
'.CODE_STATEMENT.'
';

$groups = [];
foreach ($byPath as $path => $e) { $dir = str_contains($path, '/') ? dirname($path) : '.'; $groups[$dir][] = $e; }
uksort($groups, fn($a, $b) => $a === '.' ? -1 : ($b === '.' ? 1 : strcmp($a, $b)));
foreach ($groups as $dir => $list) {
  echo '
'.h($dir === '.' ? 'application root' : $dir.'/').'
';
  foreach ($list as $e) { echo ''; }
  echo '
File
Lines
Bytes
SHA-256
'.h(basename($e['path'])).''.(!empty($e['functions']) ? ' '.count($e['functions']).' function'.(count($e['functions']) === 1 ? '' : 's').'' : '').'
'.(int)$e['lines'].'
'.number_format((int)$e['bytes']).'
'.h(substr($e['sha256'], 0, 16)).'…
';
}
echo '
'.CODE_STATEMENT.' To verify a file: download it as plain text, compute its SHA-256, compare with the manifest.
';
page_footer();