setup: Introduce class `WebModuleRequirement`

modules/setup/library/Setup/Requirement/WebModuleRequirement.php

@@ -0,0 +1,25 @@
+<?php
+/* Icinga Web 2 | (c) 2020 Icinga GmbH | GPLv2+ */
+
+namespace Icinga\Module\Setup\Requirement;
+
+use Icinga\Application\Icinga;
+use Icinga\Module\Setup\Requirement;
+
+class WebModuleRequirement extends Requirement
+{
+    protected function evaluate()
+    {
+        list($name, $op, $version) = $this->getCondition();
+
+        $mm = Icinga::app()->getModuleManager();
+        if (! $mm->hasInstalled($name)) {
+            $this->setStateText(sprintf(mt('setup', '%s is not installed'), $this->getAlias()));
+            return false;
+        }
+
+        $module = $mm->getModule($name, false);
+        $this->setStateText(sprintf(mt('setup', '%s version: %s'), $this->getAlias(), $module->getVersion()));
+        return version_compare($module->getVersion(), $version, $op);
+    }
+}