Your best bet is to use autobackup of the control file as well as snapshot. You need to make sure that the control file is the last thing that gets backed up. Then once you restore the latest control file backup, you can do a startup mount. Then your database has all of the information that it needs for you to do a "restore database;" followed by a "recover database;" you then simply do an "open database reset logs;" followed by a new backup, I would assume.
configure Controlfile autobackup format for device type disk to
configure snapshot controlfile name to
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