Hello cz48b1,
As a best practice we recommend disabling the ribbon in InfoPath. This is recommended for many reasons, but in you particular case you may want to make sure that records are not duplicated because a user decides to rename a file, or a user chooses a pre-existing file name.
For best practices we recommend using some helper fields.
1. Form Name - a field that gets set to something unique on first submit - concat(username(), "-", now()) is usually a good one to use. Also make sure this field only gets set if it is blank.
2. Form Status - a field that captures workflow step and can e leveraged in a SharePoint workflow to kick-off something like an automatic email.
In the form you can use a singular submit data connection and 2 buttons with different labels. You then use logic to enable and disable each button, depending on the form state.
Hope that helps!
Bre