Website Form generates Expiring Coupon

I can provide the coupon in PDF format or generate it in any format you wish.
I want the output to be able to be added to the a website.
I want the forms to use gravity forms (which I have )
I want the date entered in the form to be added to the coupon
I want the coupon to then be created and emailed to the user as a PDF that can not be edited.

Here is a copy of the coupon , https://www.dropbox.com/s/769plwsxchp74iu/CouponForm.pdf

which can be updated if need be to allow for what ever is needed in the document to allow for the script to edit it, adding name/email/phone to it of the intended user, along with expire date of current date +15 days.