Issue search support elasticsearch (#9428)

* Issue search support elasticsearch

* Fix lint

* Add indexer name on app.ini

* add a warnning on SearchIssuesByKeyword

* improve code

vendor/github.com/olivere/elastic/v7/suggester_term.go

@@ -0,0 +1,233 @@
+// 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
+
+// TermSuggester suggests terms based on edit distance.
+// For more details, see
+// https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-suggesters-term.html.
+type TermSuggester struct {
+	Suggester
+	name           string
+	text           string
+	field          string
+	analyzer       string
+	size           *int
+	shardSize      *int
+	contextQueries []SuggesterContextQuery
+
+	// fields specific to term suggester
+	suggestMode    string
+	accuracy       *float64
+	sort           string
+	stringDistance string
+	maxEdits       *int
+	maxInspections *int
+	maxTermFreq    *float64
+	prefixLength   *int
+	minWordLength  *int
+	minDocFreq     *float64
+}
+
+// NewTermSuggester creates a new TermSuggester.
+func NewTermSuggester(name string) *TermSuggester {
+	return &TermSuggester{
+		name: name,
+	}
+}
+
+func (q *TermSuggester) Name() string {
+	return q.name
+}
+
+func (q *TermSuggester) Text(text string) *TermSuggester {
+	q.text = text
+	return q
+}
+
+func (q *TermSuggester) Field(field string) *TermSuggester {
+	q.field = field
+	return q
+}
+
+func (q *TermSuggester) Analyzer(analyzer string) *TermSuggester {
+	q.analyzer = analyzer
+	return q
+}
+
+func (q *TermSuggester) Size(size int) *TermSuggester {
+	q.size = &size
+	return q
+}
+
+func (q *TermSuggester) ShardSize(shardSize int) *TermSuggester {
+	q.shardSize = &shardSize
+	return q
+}
+
+func (q *TermSuggester) ContextQuery(query SuggesterContextQuery) *TermSuggester {
+	q.contextQueries = append(q.contextQueries, query)
+	return q
+}
+
+func (q *TermSuggester) ContextQueries(queries ...SuggesterContextQuery) *TermSuggester {
+	q.contextQueries = append(q.contextQueries, queries...)
+	return q
+}
+
+func (q *TermSuggester) SuggestMode(suggestMode string) *TermSuggester {
+	q.suggestMode = suggestMode
+	return q
+}
+
+func (q *TermSuggester) Accuracy(accuracy float64) *TermSuggester {
+	q.accuracy = &accuracy
+	return q
+}
+
+func (q *TermSuggester) Sort(sort string) *TermSuggester {
+	q.sort = sort
+	return q
+}
+
+func (q *TermSuggester) StringDistance(stringDistance string) *TermSuggester {
+	q.stringDistance = stringDistance
+	return q
+}
+
+func (q *TermSuggester) MaxEdits(maxEdits int) *TermSuggester {
+	q.maxEdits = &maxEdits
+	return q
+}
+
+func (q *TermSuggester) MaxInspections(maxInspections int) *TermSuggester {
+	q.maxInspections = &maxInspections
+	return q
+}
+
+func (q *TermSuggester) MaxTermFreq(maxTermFreq float64) *TermSuggester {
+	q.maxTermFreq = &maxTermFreq
+	return q
+}
+
+func (q *TermSuggester) PrefixLength(prefixLength int) *TermSuggester {
+	q.prefixLength = &prefixLength
+	return q
+}
+
+func (q *TermSuggester) MinWordLength(minWordLength int) *TermSuggester {
+	q.minWordLength = &minWordLength
+	return q
+}
+
+func (q *TermSuggester) MinDocFreq(minDocFreq float64) *TermSuggester {
+	q.minDocFreq = &minDocFreq
+	return q
+}
+
+// termSuggesterRequest 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 term element.
+type termSuggesterRequest struct {
+	Text string      `json:"text"`
+	Term interface{} `json:"term"`
+}
+
+// Source generates the source for the term suggester.
+func (q *TermSuggester) Source(includeName bool) (interface{}, error) {
+	// "suggest" : {
+	//   "my-suggest-1" : {
+	//     "text" : "the amsterdma meetpu",
+	//     "term" : {
+	//       "field" : "body"
+	//     }
+	//   },
+	//   "my-suggest-2" : {
+	//     "text" : "the rottredam meetpu",
+	//     "term" : {
+	//       "field" : "title",
+	//     }
+	//   }
+	// }
+	ts := &termSuggesterRequest{}
+	if q.text != "" {
+		ts.Text = q.text
+	}
+
+	suggester := make(map[string]interface{})
+	ts.Term = suggester
+
+	if q.analyzer != "" {
+		suggester["analyzer"] = q.analyzer
+	}
+	if q.field != "" {
+		suggester["field"] = q.field
+	}
+	if q.size != nil {
+		suggester["size"] = *q.size
+	}
+	if q.shardSize != nil {
+		suggester["shard_size"] = *q.shardSize
+	}
+	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([]interface{}, len(q.contextQueries))
+		for i, query := range q.contextQueries {
+			src, err := query.Source()
+			if err != nil {
+				return nil, err
+			}
+			ctxq[i] = src
+		}
+		suggester["contexts"] = ctxq
+	}
+
+	// Specific to term suggester
+	if q.suggestMode != "" {
+		suggester["suggest_mode"] = q.suggestMode
+	}
+	if q.accuracy != nil {
+		suggester["accuracy"] = *q.accuracy
+	}
+	if q.sort != "" {
+		suggester["sort"] = q.sort
+	}
+	if q.stringDistance != "" {
+		suggester["string_distance"] = q.stringDistance
+	}
+	if q.maxEdits != nil {
+		suggester["max_edits"] = *q.maxEdits
+	}
+	if q.maxInspections != nil {
+		suggester["max_inspections"] = *q.maxInspections
+	}
+	if q.maxTermFreq != nil {
+		suggester["max_term_freq"] = *q.maxTermFreq
+	}
+	if q.prefixLength != nil {
+		suggester["prefix_length"] = *q.prefixLength
+	}
+	if q.minWordLength != nil {
+		suggester["min_word_len"] = *q.minWordLength
+	}
+	if q.minDocFreq != nil {
+		suggester["min_doc_freq"] = *q.minDocFreq
+	}
+
+	if !includeName {
+		return ts, nil
+	}
+
+	source := make(map[string]interface{})
+	source[q.name] = ts
+	return source, nil
+}