1// Copyright 2012-2015 Oliver Eilhard. All rights reserved.
2// Use of this source code is governed by a MIT-license.
3// See http://olivere.mit-license.org/license.txt for details.
4
5package elastic
6
7// MinAggregation is a single-value metrics aggregation that keeps track and
8// returns the minimum value among numeric values extracted from the
9// aggregated documents. These values can be extracted either from
10// specific numeric fields in the documents, or be generated by a
11// provided script.
12// See: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-metrics-min-aggregation.html
13type MinAggregation struct {
14	field           string
15	script          string
16	scriptFile      string
17	lang            string
18	format          string
19	params          map[string]interface{}
20	subAggregations map[string]Aggregation
21}
22
23func NewMinAggregation() MinAggregation {
24	a := MinAggregation{
25		params:          make(map[string]interface{}),
26		subAggregations: make(map[string]Aggregation),
27	}
28	return a
29}
30
31func (a MinAggregation) Field(field string) MinAggregation {
32	a.field = field
33	return a
34}
35
36func (a MinAggregation) Script(script string) MinAggregation {
37	a.script = script
38	return a
39}
40
41func (a MinAggregation) ScriptFile(scriptFile string) MinAggregation {
42	a.scriptFile = scriptFile
43	return a
44}
45
46func (a MinAggregation) Lang(lang string) MinAggregation {
47	a.lang = lang
48	return a
49}
50
51func (a MinAggregation) Format(format string) MinAggregation {
52	a.format = format
53	return a
54}
55
56func (a MinAggregation) Param(name string, value interface{}) MinAggregation {
57	a.params[name] = value
58	return a
59}
60
61func (a MinAggregation) SubAggregation(name string, subAggregation Aggregation) MinAggregation {
62	a.subAggregations[name] = subAggregation
63	return a
64}
65
66func (a MinAggregation) Source() interface{} {
67	// Example:
68	//	{
69	//    "aggs" : {
70	//      "min_price" : { "min" : { "field" : "price" } }
71	//    }
72	//	}
73	// This method returns only the { "min" : { "field" : "price" } } part.
74
75	source := make(map[string]interface{})
76	opts := make(map[string]interface{})
77	source["min"] = opts
78
79	// ValuesSourceAggregationBuilder
80	if a.field != "" {
81		opts["field"] = a.field
82	}
83	if a.script != "" {
84		opts["script"] = a.script
85	}
86	if a.scriptFile != "" {
87		opts["script_file"] = a.scriptFile
88	}
89	if a.lang != "" {
90		opts["lang"] = a.lang
91	}
92	if a.format != "" {
93		opts["format"] = a.format
94	}
95	if len(a.params) > 0 {
96		opts["params"] = a.params
97	}
98
99	// AggregationBuilder (SubAggregations)
100	if len(a.subAggregations) > 0 {
101		aggsMap := make(map[string]interface{})
102		source["aggregations"] = aggsMap
103		for name, aggregate := range a.subAggregations {
104			aggsMap[name] = aggregate.Source()
105		}
106	}
107
108	return source
109}
110