Create a wifi login page, that is linked to Instagram and Facebook.

Hi i own a shisha cafe, and we have an Instagram account which we use to share our lovely shisha images etc.. i also have free wifi at my cafe. this is my idea... 80% of my customers connect to the wifi when they visit my cafe. when a customer connects to my wifi, in order for them to use it free, i would like something to pop up, and to activate the wifi they need to follow our Instagram and like 5 of our pictures. once they have followed our instagram page and like 5 pictures the free wifi will be ready to use.