Sum results from top_hits aggregation

[alfred.bez]

Hi guys, I'm trying to sum data from an top_hits result and I need some help.

First, here's my data:

{"clientId":1, "gender": "male", "dateTime":"2017-06-06 17:54:38", "phoneIsValid":1},
{"clientId":1, "gender": "male", "dateTime":"2017-06-01 09:12:56", "phoneIsValid":1},
{"clientId":2, "gender": "female", "dateTime":"2017-06-06 17:54:38", "phoneIsValid":0},
{"clientId":3, "gender": "male", "dateTime":"2017-06-06 17:54:38", "phoneIsValid":1}

I want something like this (pseudo):

...
{
  "key": "male",
  "doc_count": 2,
  "clients": {...},
  "count_email": { "value": 2 }
},
{
  "key": "female",
  "doc_count": 1,
  "clients": {...},
  "count_email": { "value": 0 }
},
...

It's possible that we have multiple documents per client, so I need to group them an pick that with the latest "dateTime"-field:

...
"aggs": {
    "clients": {
        "terms": {
            "field": "clientId"
        },
        "aggs": {
            "latest_dateTime": {
                "max": {
                    "field": "dateTime"
                }
            }
...

I added this aggregation, since I need this field too:

"phoneIsValid": {
    "top_hits": {
        "size": 1,
        "_source": "phoneIsValid"
    }
},

Then I have this snippet, which should sum how many clients have valid phonenumbers:

"count_valid": {
    "sum": {
        "field": "clients>phoneIsValid"
    }
}

I tried the Sum Bucket Aggregation like this:

"count_valid": {
    "sum_bucket": {
        "buckets_path": "clients>phoneIsValid"
    }
}

And got the following error:

"caused_by": {
  "type": "aggregation_execution_exception",
  "reason": "buckets_path must reference either a number value or a single value numeric metric aggregation, got: org.elasticsearch.search.aggregations.metrics.tophits.InternalTopHits"
}

Here is my full query:

{
    "query": {
        "bool": {},
    "size": 0,
    "aggs": {
        "genders": {
            "terms": {
                "field": "gender"
            },
            "aggs": {
                "clients": {
                    "terms": {
                        "field": "clientId"
                    },
                    "aggs": {
                        "latest_dateTime": {
                            "max": {
                                "field": "dateTime"
                            }
                        },
                        "phoneIsValid": {
                            "top_hits": {
                                "size": 1,
                                "_source": "phoneIsValid"
                            }
                        }
                    }
                },
                "count_valid": {
                    "sum_bucket": {
                        "buckets_path": "clients>phoneIsValid"
                    }
                }
            }
        }
    }
}

I found this question: How to sum a field from top_hits results
Unfortunately this question is closed without an answer.