I'm looking for an algorithm to find unknown patterns in a string

Question

I am trying to detect patterns in huge code bases. I managed to filter the entire codebase into a tagged string, as in: ABACBABAABBCBABA

The result should be: ABA *3 CBA *2

I'm trying to build / use an algorithm which will find ANY unknown repeating pattern inside the string. The length of the pattern, it's composition, and the number of repeats is unknow.

To be a pattern it must occur atleast twice. And have atleast 2 items. Once I detect the patterns I can represent them back in their original context

I have tried iterating over each tag. For each tag find the following tag in the string. continue until adding a tag matches only one repeat - hence no more pattern.

I get lost in implemetation (in JS or Python) and I'm hoping there is a better way. Thanks.