// Copyright 2012-2015 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

// GeoBoundsAggregation is a metric aggregation that computes the
// bounding box containing all geo_point values for a field.
// See: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-metrics-geobounds-aggregation.html
type GeoBoundsAggregation struct {
	field           string
	script          *Script
	wrapLongitude   *bool
	subAggregations map[string]Aggregation
	meta            map[string]interface{}
}

func NewGeoBoundsAggregation() *GeoBoundsAggregation {
	return &GeoBoundsAggregation{
		subAggregations: make(map[string]Aggregation),
	}
}

func (a *GeoBoundsAggregation) Field(field string) *GeoBoundsAggregation {
	a.field = field
	return a
}

func (a *GeoBoundsAggregation) Script(script *Script) *GeoBoundsAggregation {
	a.script = script
	return a
}

func (a *GeoBoundsAggregation) WrapLongitude(wrapLongitude bool) *GeoBoundsAggregation {
	a.wrapLongitude = &wrapLongitude
	return a
}

func (a *GeoBoundsAggregation) SubAggregation(name string, subAggregation Aggregation) *GeoBoundsAggregation {
	a.subAggregations[name] = subAggregation
	return a
}

// Meta sets the meta data to be included in the aggregation response.
func (a *GeoBoundsAggregation) Meta(metaData map[string]interface{}) *GeoBoundsAggregation {
	a.meta = metaData
	return a
}

func (a *GeoBoundsAggregation) Source() (interface{}, error) {
	// Example:
	// {
	//     "query" : {
	//         "match" : { "business_type" : "shop" }
	//     },
	//     "aggs" : {
	//         "viewport" : {
	//             "geo_bounds" : {
	//                 "field" : "location"
	//                 "wrap_longitude" : "true"
	//             }
	//         }
	//     }
	// }
	//
	// This method returns only the { "geo_bounds" : { ... } } part.

	source := make(map[string]interface{})
	opts := make(map[string]interface{})
	source["geo_bounds"] = opts

	if a.field != "" {
		opts["field"] = a.field
	}
	if a.script != nil {
		src, err := a.script.Source()
		if err != nil {
			return nil, err
		}
		opts["script"] = src
	}
	if a.wrapLongitude != nil {
		opts["wrap_longitude"] = *a.wrapLongitude
	}

	// 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
}