As we all know, after factory reset, the content and settings will be erased from our iPhone.
If you do it mistakenly, you don't have to worry about too much.
The
iPhone data recovery for Mac [joyoshare.com] or Windows can be used to help recover data, like videos, photos, messages, call history, calendars, etc.
You also have a way to extract files from iTunes or iCloud backups with high success rate.
Related:
How to Recover Data from iPhone after Factory Reset [joyoshare.com]