Hello everyone,
I'm trying to implement subscription logic in the game, but I couldn't find any way to handle cancel/renew subscriptions. Here's the things I've tried so far: (I'm using Unity and Unity IAP plugin)
I created an empty item in the catalog so that when a player purchases a subscription, I can give them an item and do some logic on PlayFab.
First purchase is made without a problem. I can see the item in the player's inventory and I can see the receipt in the Purchases menu. The problem is when the subscription renews itself, the receipt isn't renewed, which means I have the same receipt on the client side. When I send the receipt to PlayFab, I got this log:
"Valid": true,
"Error": "Receipt already used",
Receipt validation says that the receipt is already used, which is true. I can see the receipt in the Purchases menu.
At this point, I thought that maybe I can ignore the error and use "valid" value to check if the player's subscription is still active. Just to test this value, I canceled my subscription on Play Store and sent the same receipt to PlayFab. In the log, I got the same output. Valid value was true even though I canceled my subscription and it's expired, and the error message was same.
I have no idea how I can check if the player still has a valid receipt. There is a something called "Service account key" in Google Add-on, but I don't really know what it is and if it's related to this problem. How can I handle subscriptions?
EDIT: I'm trying to make a system like this:
A player buys a subscription. The receipt gets validated on PlayFab. At this point, I need to save expiration date to the player's read only or internal data. I can't trust the client about this information. The context can be modified. The first problem is how can I get the expiration date on the server-side?
Let's say I got the expiration date and saved the date in the player's read only data. Every time the player logs in to the game, I check if the player's subscription expired or not by using the date I saved in the player's read only data. If the date indicates the future, that means the subscription is valid. I don't have to do anything. If the date indicates the past, that means the subscription needs to be renewed. At this point, I get the receipt information again from the client and check if the receipt is still active/valid (check if the player canceled the subscription on Google Play or not). Since the receipt is the same as the old one, PlayFab returns error saying receipt already used. I need to check if that receipt is still active on Play Store or not. How can I check this situation?
After checking the receipt, I need to get a new expiration date and overwrite it in the player's read only data. This process repeats itself.
While checking the receipt if the receipt is not valid/canceled, I simply need to delete the expiration date that is in the player's read only data so that I can understand that the player doesn't have a valid subscription. (When I try to read the expiration date on Cloudscript, it will return null since the key doesn't exist).
