Creating an Enrichment for URL Deduplication and Data Aggregation

Hello - I'm trying to create an enrichment that will handle deduplication according to the following algorithm:

1.
check if the URL in first column is unique to list
2.
if the URL is unique, copy the value of first column & second column into the output columns
3.
if the URL is not unique, copy the value of the first instance of the URL into the first output column, then generate a comma-separated concatenated list of unique results from the second column and add it to the second output column