Schema for handling duplicate filenames on user import?

I am developing a presentation style app (e.g. Powerpoint, Keynote) in Electron where the user can import their image files into a project folder and I am wondering how to handle the issue of potential file name conflicts.

I don't want to be reinventing wheels: are there schema, design patterns or frameworks for this sort of thing? For example on OSX, iPhoto uses date of import plus seemingly random(?) ids to organize imported images.

I will be implementing this is Javascript but am interested primarily in how to approach the problem so language doesn't matter.

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iPhoto Library: