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// 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
import "errors"
// SuggesterContextQuery is used to define context information within
// a suggestion request.
type SuggesterContextQuery interface {
Source() (interface{}, error)
}
// ContextSuggester is a fast suggester for e.g. type-ahead completion that supports filtering and boosting based on contexts.
// See https://www.elastic.co/guide/en/elasticsearch/reference/6.0/suggester-context.html
// for more details.
type ContextSuggester struct {
Suggester
name string
prefix string
field string
size *int
contextQueries []SuggesterContextQuery
}
// Creates a new context suggester.
func NewContextSuggester(name string) *ContextSuggester {
return &ContextSuggester{
name: name,
contextQueries: make([]SuggesterContextQuery, 0),
}
}
func (q *ContextSuggester) Name() string {
return q.name
}
func (q *ContextSuggester) Prefix(prefix string) *ContextSuggester {
q.prefix = prefix
return q
}
func (q *ContextSuggester) Field(field string) *ContextSuggester {
q.field = field
return q
}
func (q *ContextSuggester) Size(size int) *ContextSuggester {
q.size = &size
return q
}
func (q *ContextSuggester) ContextQuery(query SuggesterContextQuery) *ContextSuggester {
q.contextQueries = append(q.contextQueries, query)
return q
}
func (q *ContextSuggester) ContextQueries(queries ...SuggesterContextQuery) *ContextSuggester {
q.contextQueries = append(q.contextQueries, queries...)
return q
}
// contextSuggesterRequest is necessary because the order in which
// the JSON elements are routed to Elasticsearch is relevant.
// We got into trouble when using plain maps because the text element
// needs to go before the completion element.
type contextSuggesterRequest struct {
Prefix string `json:"prefix"`
Completion interface{} `json:"completion"`
}
// Creates the source for the context suggester.
func (q *ContextSuggester) Source(includeName bool) (interface{}, error) {
cs := &contextSuggesterRequest{}
if q.prefix != "" {
cs.Prefix = q.prefix
}
suggester := make(map[string]interface{})
cs.Completion = suggester
if q.field != "" {
suggester["field"] = q.field
}
if q.size != nil {
suggester["size"] = *q.size
}
switch len(q.contextQueries) {
case 0:
case 1:
src, err := q.contextQueries[0].Source()
if err != nil {
return nil, err
}
suggester["contexts"] = src
default:
ctxq := make(map[string]interface{})
for _, query := range q.contextQueries {
src, err := query.Source()
if err != nil {
return nil, err
}
// Merge the dictionary into ctxq
m, ok := src.(map[string]interface{})
if !ok {
return nil, errors.New("elastic: context query is not a map")
}
for k, v := range m {
ctxq[k] = v
}
}
suggester["contexts"] = ctxq
}
if !includeName {
return cs, nil
}
source := make(map[string]interface{})
source[q.name] = cs
return source, nil
}
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