CMS Project with Drag n drop, build a site

Hi Everyone, 

I'm new to the forums and new to Codeigniter. 

I understand that it is possible to use Codeigniter to create a content management system.  I'd like to look at creating a content management system that allows the user to choose a template design, add new features (plugins) and allow for new updates to be applied on the fly.  If the user doesn't choose a pre-defined template they can essentially create their own using a drag and drop system of different features, eventually ending up with a complete website.  

I'd be very interested to hear whether this is possible and the best place to get started.  

I look forward to hearing from anyone. 

Regards

Robert