need ideas for this issue

I have 1000 coupons of non wordpress site and I want to sell it in wordpress site
I need the next
instead of creating 1000 product for the 1000 coupons
I need to a way to add 1000 coupon to only one product and every time some user purchase the number of coupon become 999 and the second time any user purchase the number become 998 and thus till all is finished to be out of stock

any one have any idea or any plugin to do this process

thank you in advanced