Nest Bulk update in elasticsearch

[piyush_kumar]

Elasticsearch - 6.5.1
Nest - 6.5.1

Hi All,

I am able to write code to update the single document 1 at a time.

var scriptParams = new Dictionary<string, object>
{
    {"id", BaseMapping.id}
};
return Client.UpdateByQuery<BaseMapping>(s => s
    .Query(q => q
        .Match(m => m
            .Field(f => f.question_id.Suffix("raw"))
            .Query(BaseMapping.id.ToString())
        )
    )
    .Script(script =>
        script.Source((
                $"ctx._source.id=params.id;" +
                $"ctx._source.answer='" + BaseMapping.answer + "';" +
                $"ctx._source.question='" + BaseMapping.question + "';" 
            )
            )
        .Params(scriptParams)
        )
    .Conflicts(Elasticsearch.Net.Conflicts.Proceed)
 );

I wanted to write code which can do a bulk update with below logic
1-check if the document exists based on _id then update the existing document and if it doesn't exist then insert the document.

I have referred one code from the elasticsearch documentation.

POST twitter/_update_by_query
{
  "script": {
    "source": "if (ctx._source.tags.contains(params.tag)) { ctx.op = 'update' } else { ctx.op = 'insert' }",
    "lang": "painless"
  },
  "query": {
    "term": {
      "user": "kimchy"
    }
  }
}

can anybody help me with how to write it in Nest bulk update.?