Link: Google Cloud Storage with suffixed unsubscribe bucket

type.inbound
// two distinct paths
and length(distinct(map(filter(body.links,
                               .href_url.domain.domain == "storage.googleapis.com"
                        ),
                        .href_url.path
                    )
           )
) == 2
// split each distinct path into bucket and trailer once
and any(map(distinct(filter(body.links,
                            .href_url.domain.domain == "storage.googleapis.com"
                     ),
                     .href_url.path
            ),
            // return just the bucket/trailer for the path
            regex.extract(.href_url.path,
                          '^/(?P<bucket>[^/]+)/(?P<trailer>.+)$'
            )[0]
        ),
        // loop the links that aren't the current .href_url.path (from the outer loop)
        any(map(distinct(filter(body.links,
                                .href_url.domain.domain == "storage.googleapis.com"
                                and .href_url.path != ..full_match
                         ),
                         // return just the .href_url.path
                         .href_url.path
                ),
                // create the bucket/trailer for the path
                regex.extract(.href_url.path,
                              '^/(?P<bucket>[^/]+)/(?P<trailer>.+)$'
                )[0]
            ),
            // this bucket is the outer bucket plus a suffix, serving the same trailer
            strings.starts_with(.named_groups['bucket'],
                                ..named_groups['bucket']
            )
            and .named_groups['trailer'] == ..named_groups['trailer']
        )
)