public function actionIndex()
    {
        $error = false;

        @chdir(Yii::getAlias('@app'));

        $this->output('The directory the health commands is applying to: ' . Yii::getAlias('@app'));
        
        foreach ($this->folders as $folder => $writable) {
            $mode = ($writable) ? 0777 : 0775;
            if (!file_exists($folder)) {
                if (FileHelper::createDirectory($folder, $mode)) {
                    $this->outputSuccess("$folder: successfully created directory");
                } else {
                    $error = true;
                    $this->outputError("$folder: unable to create directory");
                }
            } else {
                $this->outputInfo("$folder: directory exists already");
            }
            
            if ($writable && !is_writable($folder)) {
                $this->outputInfo("$folder: is not writeable, try to set mode '$mode'.");
                @chmod($folder, $mode);
            }

            if ($writable) {
                if (!is_writable($folder)) {
                    $error = true;
                    $this->outputError("$folder: is not writable, please change permissions.");
                }
            }
        }

        foreach ($this->files as $file) {
            if (file_exists($file)) {
                $this->outputInfo("$file: file exists.");
            } else {
                $error = true;
                $this->outputError("$file: file does not exists!");
            }
        }
        
        return $error ? $this->outputError('Health check found errors!') : $this->outputSuccess('O.K.');
    }