I am currently programming coredata, icloud, and in-app subscriptions. Currently, I have created an app that stores and synchronizes notes with icloud. In addition, many notes have already been stored in icloud before. However, subscriptions in the app If not done, only coredata is used to save memos. In the future, if a user subscribes and activates the icloud function, all of the coredata contents written in the basic will disappear, and only memos previously stored in icloud will be synchronized with coredata. It's possible. To sum up, is it theoretically impossible to update coredata and icloud contents by combining the previous icloud memo contents and coredata memo contents when the user starts the icloud in-app subscription after saving the memos only in coredata when the user has not subscribed?
(Should I upload and merge the contents stored in the coredata stored in the device to icloud when connecting to icloud when subscribing, and then synchronize the icloud contents to the coredata of the device again?)