ESP8266 RESET and PUBLIC IP Discovery

Hell, I have an already Arduino project for my ESP8266 module and would like to add just 2 functions. 1st is the reset or factory default function that if press GPIO-0 for more than 5-10sec It will go back or reset all inputs or details on my existing Arduino application. This is like any device that you buy and after set your own details, but if you press for a long time it will reset all the fields, so you can start over from beginning. The 2nd. step is to detect the public ip of my home network and if this Public IP changes then It will discover the new one and send by SMS to the USER phone number. Note that all SMS API are working and SMS system as well. my Current project is working 100% but need to add these 2 functions. THIS IS SIMPLE AND DO. NOT GET CONFUSE ABOUT THIS LONG TEXT. I COULD RESUME IN A SHORT WAY IF WOULD LIKE TO PARTICIPATE.