I am trying to implement IAP with Auto-renewable subscriptions in my app. My app has his own system of users and I want to implement this behaviour:
In the same device, if the user logged buy a subscription, then the user logout and other user login, I want to this user can buy is own subscription.
All the information about what user has buy the subscription, with all the info about the transaction can be save in a server side, but even I can handle that, for avoid restore when the user which is logged is not the user which bought the subscriptions, but still this user can not buy a subscription because it show a popup which said "You are currently subscribed".
There is a way to implement this behaviour? or for each Apple ID only can be one subscription active at the same time? There is a way of with same Apple ID, to different users of my own system account of my app logged can buy two subscription?
I'm not sure to understand your question... An Apple ID can only have one active auto-renewable subscription to a product at the same time. If multiple users share the same device : if a user buy a subscription, log-out, then another user log-in and buy a subscription it will work. The subscription is linked to the user's Apple ID.