Sending codes

I have an online store selling game cards and I would like to provide a system or for selling codes to provide the following services:

. Add several codes, for example 5 licenses per game / card. When the customer buys the game or card and is approved his code will appear in his account License No. 1 to be able to use it, and become the remaining product codes 4 This is done automatically.
. When codes reach a certain limit, for example, 3 codes, the management will receive an email notification that the game / card has reached the minimum of the codes.
. When the customer bought 2 codes, will receive two codes in one application and will be deducted from the total number of codes automatically.
. When payment is made by PayPal or Credit Card, the codes will be emailed to the customer and appears in his / her account automatically.

Any post ??