Adding version checking

includes/functions.php

@@ -180,6 +180,64 @@ function run_fetch(): array {
     return $results;
 }
 
+// ── Upstream version check ────────────────────────────────────────────────────
+
+define('UPSTREAM_VERSION_URL', 'https://git.ny.daprogs.com/api/v1/repos/DAProgs/portspoof_concentrator/raw/version.php?ref=main');
+define('UPSTREAM_VERSION_CACHE', __DIR__ . '/../upstream_version.cache');
+define('UPSTREAM_VERSION_TTL', 3600); // seconds
+
+/**
+ * Fetch the upstream version string from the git repo, with a 1-hour file cache.
+ * Returns null silently on any failure so the page always loads.
+ */
+function fetch_upstream_version(): ?string {
+    // Return cached value if still fresh
+    if (file_exists(UPSTREAM_VERSION_CACHE)) {
+        $cached = json_decode(file_get_contents(UPSTREAM_VERSION_CACHE), true);
+        if (isset($cached['version'], $cached['checked_at'])
+            && (time() - $cached['checked_at']) < UPSTREAM_VERSION_TTL) {
+            return $cached['version'];
+        }
+    }
+
+    $ch = curl_init(UPSTREAM_VERSION_URL);
+    curl_setopt_array($ch, [
+        CURLOPT_RETURNTRANSFER => true,
+        CURLOPT_TIMEOUT        => 5,
+        CURLOPT_FOLLOWLOCATION => true,
+    ]);
+    $body = curl_exec($ch);
+    $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+    curl_close($ch);
+
+    if ($body === false || $code !== 200) {
+        return null;
+    }
+
+    if (!preg_match("/define\s*\(\s*'APP_VERSION'\s*,\s*'([^']+)'\s*\)/", $body, $m)) {
+        return null;
+    }
+
+    $version = $m[1];
+    file_put_contents(
+        UPSTREAM_VERSION_CACHE,
+        json_encode(['version' => $version, 'checked_at' => time()]),
+        LOCK_EX
+    );
+    return $version;
+}
+
+/**
+ * Returns true if $upstream is a newer version than $local.
+ * Format: YYMM.N  e.g. 2603.4
+ */
+function is_newer_version(string $upstream, string $local): bool {
+    $parse = fn($v) => array_map('intval', explode('.', $v, 2));
+    [$um, $un] = $parse($upstream);
+    [$lm, $ln] = $parse($local);
+    return $um > $lm || ($um === $lm && $un > $ln);
+}
+
 // ── API queries ───────────────────────────────────────────────────────────────
 
 /**