Auto merge
Linked to the pull request https://github.com/nextcloud/contacts/pull/2756#issue-1246324202
Allow to automatically merge contacts who have the same Fullname, Phone number or Email adress
How it works
When the auto merge button is clicked, all the contacts which have the same Fullname, phone number or email adress will be merged together

Nice work @MrPompom! :)
To prevent mistakes, what do you think of doing it in a way similar to other Contacts apps which have a "Merge duplicates" entry if there are duplicates?
Then people can go through the suspected duplicates and double check, instead of possibly merging some correct and some wrong.
who have the same Fullname, Phone number or Email adress
I'm not able to read this from your code, so is this condition an or or an and? In larger organizations there are often people with the same full name. E.g. we had customer issues about this when the share menu wasn't distinguishable and now it also shows the email address. So it's important that the match is based on more than just the fullname.
First of all, thanks for your contribution.
I like the idea but I'm concerned with the UX. Automatically merging contacts involves too much magic. IMO, we should implement some form of dialog/preview similar to what Jan said.
Hi, I'll add something to look over ... maybe this is helpful to determine duplicates:
I might show something, what could help to identify duplicates ... Maybe you know a software called gSyncIt (https://www.fieldstonsoftware.com/software/gsyncit5/?gclid=CjwKCAjw-rOaBhA9EiwAUkLV4ncJIelfTRjuFwlpUvZZsE461VARySjZRqJ7x9wqoIzWwdVNHeMNMRoCbeIQAvD_BwE
This software contains a functionality to determine duplicates and "delete" them (move them to the recycle bin). Of course we don't want a delete, but I would appreciate something like this. In this software you can define the fields that should be compared and only if all of these criteria are identical we have a duplicate. Something like this would be great for NextCloud-Contacts.
@MrPompom could you pleaes have a look at the feedback above?