Integrating A Php Page With Prestashop In The Front End

[JERRY777]

When customer clicks  'Add To Cart' from the front end page of Prestashop, I want to show a php page in a popup ,now by default a popup with below message is appearing when we click Add to Cart button.

Product successfully added to your shopping cart , screen shot of the current default pop up is shown, before this pop up appear I want  to make customer to select a ticket related to a particular product, so after selecting the ticket  the default pop up must appear and proceed  to the payment gateway page .

  The php page which I  developed for displaying tickets (cinema tickets, ticket may vary from 1- 5000 )  depending on  the product I need to show different tickets  page /different php page  depending upon the product choose ( screen shot of the page attached), So by this  customer can choose the ticket  and proceed to the payment.

I tried to look into modules\blockcart module ,but   still struggling  so can you please   just guide me where to edit  or how to edit to achieve  this customization so that I can integrate my ticket page when customer clicks   the Add to Cart button. I am php developer and trying to learn this prestashop (new to prestashop) and and I am developing and implementing a prestashop based ticket website , So please  help in integrating a php page to the prestashop by editing the core prestashop php files.