Add --no-alt and --skip-extract option to install-pkg command

src/SPC/store/Downloader.php

@@ -608,6 +608,29 @@ class Downloader
         return "{$source}-{$os_family}-{$gnu_arch}-{$libc}-{$libc_version}";
     }
 
+    public static function getDefaultAlternativeSource(string $source_name): array
+    {
+        return [
+            'type' => 'custom',
+            'func' => function (bool $force, array $source, int $download_as) use ($source_name) {
+                logger()->debug("Fetching alternative source for {$source_name}");
+                // get from dl.static-php.dev
+                $url = "https://dl.static-php.dev/static-php-cli/deps/spc-download-mirror/{$source_name}/?format=json";
+                $json = json_decode(Downloader::curlExec(url: $url, retries: intval(getenv('SPC_DOWNLOAD_RETRIES') ?: 0)), true);
+                if (!is_array($json)) {
+                    throw new RuntimeException('failed http fetch');
+                }
+                $item = $json[0] ?? null;
+                if ($item === null) {
+                    throw new RuntimeException('failed to parse json');
+                }
+                $full_url = 'https://dl.static-php.dev' . $item['full_path'];
+                $filename = basename($item['full_path']);
+                Downloader::downloadFile($source_name, $full_url, $filename, $source['path'] ?? null, $download_as);
+            },
+        ];
+    }
+
     /**
      * Register CTRL+C event for different OS.
      *