text: // Copyright 2012-present Oliver Eilhard. All rights reserved.
  // Use of this source code is governed by a MIT-license.
  // See http://olivere.mit-license.org/license.txt for details.
  
  package elastic
  
  // BucketScriptAggregation is a parent pipeline aggregation which executes
  // a script which can perform per bucket computations on specified metrics
  // in the parent multi-bucket aggregation. The specified metric must be
  // numeric and the script must return a numeric value.
  //
  // For more details, see
  // https://www.elastic.co/guide/en/elasticsearch/reference/6.0/search-aggregations-pipeline-bucket-script-aggregation.html
  type BucketScriptAggregation struct {
  	format    string
  	gapPolicy string
  	script    *Script
  
  	subAggregations map[string]Aggregation
  	meta            map[string]interface{}
  	bucketsPathsMap map[string]string
  }
  
  // NewBucketScriptAggregation creates and initializes a new BucketScriptAggregation.
  func NewBucketScriptAggregation() *BucketScriptAggregation {
  	return &BucketScriptAggregation{
  		subAggregations: make(map[string]Aggregation),
  		bucketsPathsMap: make(map[string]string),
  	}
  }
  
  func (a *BucketScriptAggregation) Format(format string) *BucketScriptAggregation {
  	a.format = format
  	return a
  }
  
  // GapPolicy defines what should be done when a gap in the series is discovered.
  // Valid values include "insert_zeros" or "skip". Default is "insert_zeros".
  func (a *BucketScriptAggregation) GapPolicy(gapPolicy string) *BucketScriptAggregation {
  	a.gapPolicy = gapPolicy
  	return a
  }
  
  // GapInsertZeros inserts zeros for gaps in the series.
  func (a *BucketScriptAggregation) GapInsertZeros() *BucketScriptAggregation {
  	a.gapPolicy = "insert_zeros"
  	return a
  }
  
  // GapSkip skips gaps in the series.
  func (a *BucketScriptAggregation) GapSkip() *BucketScriptAggregation {
  	a.gapPolicy = "skip"
  	return a
  }
  
  // Script is the script to run.
  func (a *BucketScriptAggregation) Script(script *Script) *BucketScriptAggregation {
  	a.script = script
  	return a
  }
  
  // SubAggregation adds a sub-aggregation to this aggregation.
  func (a *BucketScriptAggregation) SubAggregation(name string, subAggregation Aggregation) *BucketScriptAggregation {
  	a.subAggregations[name] = subAggregation
  	return a
  }
  
  // Meta sets the meta data to be included in the aggregation response.
  func (a *BucketScriptAggregation) Meta(metaData map[string]interface{}) *BucketScriptAggregation {
  	a.meta = metaData
  	return a
  }
  
  // BucketsPathsMap sets the paths to the buckets to use for this pipeline aggregator.
  func (a *BucketScriptAggregation) BucketsPathsMap(bucketsPathsMap map[string]string) *BucketScriptAggregation {
  	a.bucketsPathsMap = bucketsPathsMap
  	return a
  }
  
  // AddBucketsPath adds a bucket path to use for this pipeline aggregator.
  func (a *BucketScriptAggregation) AddBucketsPath(name, path string) *BucketScriptAggregation {
  	if a.bucketsPathsMap == nil {
  		a.bucketsPathsMap = make(map[string]string)
  	}
  	a.bucketsPathsMap[name] = path
  	return a
  }
  
  func (a *BucketScriptAggregation) Source() (interface{}, error) {
  	source := make(map[string]interface{})
  	params := make(map[string]interface{})
  	source["bucket_script"] = params
  
  	if a.format != "" {
  		params["format"] = a.format
  	}
  	if a.gapPolicy != "" {
  		params["gap_policy"] = a.gapPolicy
  	}
  	if a.script != nil {
  		src, err := a.script.Source()
  		if err != nil {
  			return nil, err
  		}
  		params["script"] = src
  	}
  
  	// Add buckets paths
  	if len(a.bucketsPathsMap) > 0 {
  		params["buckets_path"] = a.bucketsPathsMap
  	}
  
  	// AggregationBuilder (SubAggregations)
  	if len(a.subAggregations) > 0 {
  		aggsMap := make(map[string]interface{})
  		source["aggregations"] = aggsMap
  		for name, aggregate := range a.subAggregations {
  			src, err := aggregate.Source()
  			if err != nil {
  				return nil, err
  			}
  			aggsMap[name] = src
  		}
  	}
  
  	// Add Meta data if available
  	if len(a.meta) > 0 {
  		source["meta"] = a.meta
  	}
  
  	return source, nil
  }
  