How To Turn Yii Into A Full-Fledged, Social-Networking Site

I would like to create social networking site like Facebook using Yii, where in site users can post comment, share photos, and set privacy for there post.

Yes there are many open source applications available for social networking like Jom Social - For Joomla , AroundMe

Is there any extension, module available which we can use for creating social networking. or how to configure users, auth, roles rights etc module to get social networking platform.


Build on Rails, not Yii/php

Thanks…but I am specifically looking for Yii extension or how we can integrate social networking in yii