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_completion.go

@@ -0,0 +1,358 @@
+// 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"
+
+// CompletionSuggester is a fast suggester for e.g. type-ahead completion.
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-suggesters-completion.html
+// for more details.
+type CompletionSuggester struct {
+	Suggester
+	name           string
+	text           string
+	prefix         string
+	regex          string
+	field          string
+	analyzer       string
+	size           *int
+	shardSize      *int
+	contextQueries []SuggesterContextQuery
+
+	fuzzyOptions   *FuzzyCompletionSuggesterOptions
+	regexOptions   *RegexCompletionSuggesterOptions
+	skipDuplicates *bool
+}
+
+// Creates a new completion suggester.
+func NewCompletionSuggester(name string) *CompletionSuggester {
+	return &CompletionSuggester{
+		name: name,
+	}
+}
+
+func (q *CompletionSuggester) Name() string {
+	return q.name
+}
+
+func (q *CompletionSuggester) Text(text string) *CompletionSuggester {
+	q.text = text
+	return q
+}
+
+func (q *CompletionSuggester) Prefix(prefix string) *CompletionSuggester {
+	q.prefix = prefix
+	return q
+}
+
+func (q *CompletionSuggester) PrefixWithEditDistance(prefix string, editDistance interface{}) *CompletionSuggester {
+	q.prefix = prefix
+	q.fuzzyOptions = NewFuzzyCompletionSuggesterOptions().EditDistance(editDistance)
+	return q
+}
+
+func (q *CompletionSuggester) PrefixWithOptions(prefix string, options *FuzzyCompletionSuggesterOptions) *CompletionSuggester {
+	q.prefix = prefix
+	q.fuzzyOptions = options
+	return q
+}
+
+func (q *CompletionSuggester) FuzzyOptions(options *FuzzyCompletionSuggesterOptions) *CompletionSuggester {
+	q.fuzzyOptions = options
+	return q
+}
+
+func (q *CompletionSuggester) Fuzziness(fuzziness interface{}) *CompletionSuggester {
+	if q.fuzzyOptions == nil {
+		q.fuzzyOptions = NewFuzzyCompletionSuggesterOptions()
+	}
+	q.fuzzyOptions = q.fuzzyOptions.EditDistance(fuzziness)
+	return q
+}
+
+func (q *CompletionSuggester) Regex(regex string) *CompletionSuggester {
+	q.regex = regex
+	return q
+}
+
+func (q *CompletionSuggester) RegexWithOptions(regex string, options *RegexCompletionSuggesterOptions) *CompletionSuggester {
+	q.regex = regex
+	q.regexOptions = options
+	return q
+}
+
+func (q *CompletionSuggester) RegexOptions(options *RegexCompletionSuggesterOptions) *CompletionSuggester {
+	q.regexOptions = options
+	return q
+}
+
+func (q *CompletionSuggester) SkipDuplicates(skipDuplicates bool) *CompletionSuggester {
+	q.skipDuplicates = &skipDuplicates
+	return q
+}
+
+func (q *CompletionSuggester) Field(field string) *CompletionSuggester {
+	q.field = field
+	return q
+}
+
+func (q *CompletionSuggester) Analyzer(analyzer string) *CompletionSuggester {
+	q.analyzer = analyzer
+	return q
+}
+
+func (q *CompletionSuggester) Size(size int) *CompletionSuggester {
+	q.size = &size
+	return q
+}
+
+func (q *CompletionSuggester) ShardSize(shardSize int) *CompletionSuggester {
+	q.shardSize = &shardSize
+	return q
+}
+
+func (q *CompletionSuggester) ContextQuery(query SuggesterContextQuery) *CompletionSuggester {
+	q.contextQueries = append(q.contextQueries, query)
+	return q
+}
+
+func (q *CompletionSuggester) ContextQueries(queries ...SuggesterContextQuery) *CompletionSuggester {
+	q.contextQueries = append(q.contextQueries, queries...)
+	return q
+}
+
+// completionSuggesterRequest 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 completionSuggesterRequest struct {
+	Text       string      `json:"text,omitempty"`
+	Prefix     string      `json:"prefix,omitempty"`
+	Regex      string      `json:"regex,omitempty"`
+	Completion interface{} `json:"completion,omitempty"`
+}
+
+// Source creates the JSON data for the completion suggester.
+func (q *CompletionSuggester) Source(includeName bool) (interface{}, error) {
+	cs := &completionSuggesterRequest{}
+
+	if q.text != "" {
+		cs.Text = q.text
+	}
+	if q.prefix != "" {
+		cs.Prefix = q.prefix
+	}
+	if q.regex != "" {
+		cs.Regex = q.regex
+	}
+
+	suggester := make(map[string]interface{})
+	cs.Completion = 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(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
+	}
+
+	// Fuzzy options
+	if q.fuzzyOptions != nil {
+		src, err := q.fuzzyOptions.Source()
+		if err != nil {
+			return nil, err
+		}
+		suggester["fuzzy"] = src
+	}
+
+	// Regex options
+	if q.regexOptions != nil {
+		src, err := q.regexOptions.Source()
+		if err != nil {
+			return nil, err
+		}
+		suggester["regex"] = src
+	}
+
+	if q.skipDuplicates != nil {
+		suggester["skip_duplicates"] = *q.skipDuplicates
+	}
+
+	// TODO(oe) Add completion-suggester specific parameters here
+
+	if !includeName {
+		return cs, nil
+	}
+
+	source := make(map[string]interface{})
+	source[q.name] = cs
+	return source, nil
+}
+
+// -- Fuzzy options --
+
+// FuzzyCompletionSuggesterOptions represents the options for fuzzy completion suggester.
+type FuzzyCompletionSuggesterOptions struct {
+	editDistance          interface{}
+	transpositions        *bool
+	minLength             *int
+	prefixLength          *int
+	unicodeAware          *bool
+	maxDeterminizedStates *int
+}
+
+// NewFuzzyCompletionSuggesterOptions initializes a new FuzzyCompletionSuggesterOptions instance.
+func NewFuzzyCompletionSuggesterOptions() *FuzzyCompletionSuggesterOptions {
+	return &FuzzyCompletionSuggesterOptions{}
+}
+
+// EditDistance specifies the maximum number of edits, e.g. a number like "1" or "2"
+// or a string like "0..2" or ">5".
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/common-options.html#fuzziness
+// for details.
+func (o *FuzzyCompletionSuggesterOptions) EditDistance(editDistance interface{}) *FuzzyCompletionSuggesterOptions {
+	o.editDistance = editDistance
+	return o
+}
+
+// Transpositions, if set to true, are counted as one change instead of two (defaults to true).
+func (o *FuzzyCompletionSuggesterOptions) Transpositions(transpositions bool) *FuzzyCompletionSuggesterOptions {
+	o.transpositions = &transpositions
+	return o
+}
+
+// MinLength represents the minimum length of the input before fuzzy suggestions are returned (defaults to 3).
+func (o *FuzzyCompletionSuggesterOptions) MinLength(minLength int) *FuzzyCompletionSuggesterOptions {
+	o.minLength = &minLength
+	return o
+}
+
+// PrefixLength represents the minimum length of the input, which is not checked for
+// fuzzy alternatives (defaults to 1).
+func (o *FuzzyCompletionSuggesterOptions) PrefixLength(prefixLength int) *FuzzyCompletionSuggesterOptions {
+	o.prefixLength = &prefixLength
+	return o
+}
+
+// UnicodeAware, if true, all measurements (like fuzzy edit distance, transpositions, and lengths)
+// are measured in Unicode code points instead of in bytes. This is slightly slower than
+// raw bytes, so it is set to false by default.
+func (o *FuzzyCompletionSuggesterOptions) UnicodeAware(unicodeAware bool) *FuzzyCompletionSuggesterOptions {
+	o.unicodeAware = &unicodeAware
+	return o
+}
+
+// MaxDeterminizedStates is currently undocumented in Elasticsearch. It represents
+// the maximum automaton states allowed for fuzzy expansion.
+func (o *FuzzyCompletionSuggesterOptions) MaxDeterminizedStates(max int) *FuzzyCompletionSuggesterOptions {
+	o.maxDeterminizedStates = &max
+	return o
+}
+
+// Source creates the JSON data.
+func (o *FuzzyCompletionSuggesterOptions) Source() (interface{}, error) {
+	out := make(map[string]interface{})
+
+	if o.editDistance != nil {
+		out["fuzziness"] = o.editDistance
+	}
+	if o.transpositions != nil {
+		out["transpositions"] = *o.transpositions
+	}
+	if o.minLength != nil {
+		out["min_length"] = *o.minLength
+	}
+	if o.prefixLength != nil {
+		out["prefix_length"] = *o.prefixLength
+	}
+	if o.unicodeAware != nil {
+		out["unicode_aware"] = *o.unicodeAware
+	}
+	if o.maxDeterminizedStates != nil {
+		out["max_determinized_states"] = *o.maxDeterminizedStates
+	}
+
+	return out, nil
+}
+
+// -- Regex options --
+
+// RegexCompletionSuggesterOptions represents the options for regex completion suggester.
+type RegexCompletionSuggesterOptions struct {
+	flags                 interface{} // string or int
+	maxDeterminizedStates *int
+}
+
+// NewRegexCompletionSuggesterOptions initializes a new RegexCompletionSuggesterOptions instance.
+func NewRegexCompletionSuggesterOptions() *RegexCompletionSuggesterOptions {
+	return &RegexCompletionSuggesterOptions{}
+}
+
+// Flags represents internal regex flags.
+// Possible flags are ALL (default), ANYSTRING, COMPLEMENT, EMPTY, INTERSECTION, INTERVAL, or NONE.
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-suggesters-completion.html#regex
+// for details.
+func (o *RegexCompletionSuggesterOptions) Flags(flags interface{}) *RegexCompletionSuggesterOptions {
+	o.flags = flags
+	return o
+}
+
+// MaxDeterminizedStates represents the maximum automaton states allowed for regex expansion.
+//
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-suggesters-completion.html#regex
+// for details.
+func (o *RegexCompletionSuggesterOptions) MaxDeterminizedStates(max int) *RegexCompletionSuggesterOptions {
+	o.maxDeterminizedStates = &max
+	return o
+}
+
+// Source creates the JSON data.
+func (o *RegexCompletionSuggesterOptions) Source() (interface{}, error) {
+	out := make(map[string]interface{})
+
+	if o.flags != nil {
+		out["flags"] = o.flags
+	}
+	if o.maxDeterminizedStates != nil {
+		out["max_determinized_states"] = *o.maxDeterminizedStates
+	}
+
+	return out, nil
+}