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/explain.go

@@ -0,0 +1,390 @@
+// 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 (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/olivere/elastic/v7/uritemplates"
+)
+
+// ExplainService computes a score explanation for a query and
+// a specific document.
+// See https://www.elastic.co/guide/en/elasticsearch/reference/7.0/search-explain.html.
+type ExplainService struct {
+	client *Client
+
+	pretty     *bool       // pretty format the returned JSON response
+	human      *bool       // return human readable values for statistics
+	errorTrace *bool       // include the stack trace of returned errors
+	filterPath []string    // list of filters used to reduce the response
+	headers    http.Header // custom request-level HTTP headers
+
+	id                     string
+	index                  string
+	typ                    string
+	q                      string
+	routing                string
+	lenient                *bool
+	analyzer               string
+	df                     string
+	fields                 []string
+	lowercaseExpandedTerms *bool
+	xSourceInclude         []string
+	analyzeWildcard        *bool
+	parent                 string
+	preference             string
+	xSource                []string
+	defaultOperator        string
+	xSourceExclude         []string
+	source                 string
+	bodyJson               interface{}
+	bodyString             string
+}
+
+// NewExplainService creates a new ExplainService.
+func NewExplainService(client *Client) *ExplainService {
+	return &ExplainService{
+		client:         client,
+		typ:            "_doc",
+		xSource:        make([]string, 0),
+		xSourceExclude: make([]string, 0),
+		fields:         make([]string, 0),
+		xSourceInclude: make([]string, 0),
+	}
+}
+
+// Pretty tells Elasticsearch whether to return a formatted JSON response.
+func (s *ExplainService) Pretty(pretty bool) *ExplainService {
+	s.pretty = &pretty
+	return s
+}
+
+// Human specifies whether human readable values should be returned in
+// the JSON response, e.g. "7.5mb".
+func (s *ExplainService) Human(human bool) *ExplainService {
+	s.human = &human
+	return s
+}
+
+// ErrorTrace specifies whether to include the stack trace of returned errors.
+func (s *ExplainService) ErrorTrace(errorTrace bool) *ExplainService {
+	s.errorTrace = &errorTrace
+	return s
+}
+
+// FilterPath specifies a list of filters used to reduce the response.
+func (s *ExplainService) FilterPath(filterPath ...string) *ExplainService {
+	s.filterPath = filterPath
+	return s
+}
+
+// Header adds a header to the request.
+func (s *ExplainService) Header(name string, value string) *ExplainService {
+	if s.headers == nil {
+		s.headers = http.Header{}
+	}
+	s.headers.Add(name, value)
+	return s
+}
+
+// Headers specifies the headers of the request.
+func (s *ExplainService) Headers(headers http.Header) *ExplainService {
+	s.headers = headers
+	return s
+}
+
+// Id is the document ID.
+func (s *ExplainService) Id(id string) *ExplainService {
+	s.id = id
+	return s
+}
+
+// Index is the name of the index.
+func (s *ExplainService) Index(index string) *ExplainService {
+	s.index = index
+	return s
+}
+
+// Type is the type of the document.
+//
+// Deprecated: Types are in the process of being removed.
+func (s *ExplainService) Type(typ string) *ExplainService {
+	s.typ = typ
+	return s
+}
+
+// Source is the URL-encoded query definition (instead of using the request body).
+func (s *ExplainService) Source(source string) *ExplainService {
+	s.source = source
+	return s
+}
+
+// XSourceExclude is a list of fields to exclude from the returned _source field.
+func (s *ExplainService) XSourceExclude(xSourceExclude ...string) *ExplainService {
+	s.xSourceExclude = append(s.xSourceExclude, xSourceExclude...)
+	return s
+}
+
+// Lenient specifies whether format-based query failures
+// (such as providing text to a numeric field) should be ignored.
+func (s *ExplainService) Lenient(lenient bool) *ExplainService {
+	s.lenient = &lenient
+	return s
+}
+
+// Query in the Lucene query string syntax.
+func (s *ExplainService) Q(q string) *ExplainService {
+	s.q = q
+	return s
+}
+
+// Routing sets a specific routing value.
+func (s *ExplainService) Routing(routing string) *ExplainService {
+	s.routing = routing
+	return s
+}
+
+// AnalyzeWildcard specifies whether wildcards and prefix queries
+// in the query string query should be analyzed (default: false).
+func (s *ExplainService) AnalyzeWildcard(analyzeWildcard bool) *ExplainService {
+	s.analyzeWildcard = &analyzeWildcard
+	return s
+}
+
+// Analyzer is the analyzer for the query string query.
+func (s *ExplainService) Analyzer(analyzer string) *ExplainService {
+	s.analyzer = analyzer
+	return s
+}
+
+// Df is the default field for query string query (default: _all).
+func (s *ExplainService) Df(df string) *ExplainService {
+	s.df = df
+	return s
+}
+
+// Fields is a list of fields to return in the response.
+func (s *ExplainService) Fields(fields ...string) *ExplainService {
+	s.fields = append(s.fields, fields...)
+	return s
+}
+
+// LowercaseExpandedTerms specifies whether query terms should be lowercased.
+func (s *ExplainService) LowercaseExpandedTerms(lowercaseExpandedTerms bool) *ExplainService {
+	s.lowercaseExpandedTerms = &lowercaseExpandedTerms
+	return s
+}
+
+// XSourceInclude is a list of fields to extract and return from the _source field.
+func (s *ExplainService) XSourceInclude(xSourceInclude ...string) *ExplainService {
+	s.xSourceInclude = append(s.xSourceInclude, xSourceInclude...)
+	return s
+}
+
+// DefaultOperator is the default operator for query string query (AND or OR).
+func (s *ExplainService) DefaultOperator(defaultOperator string) *ExplainService {
+	s.defaultOperator = defaultOperator
+	return s
+}
+
+// Parent is the ID of the parent document.
+func (s *ExplainService) Parent(parent string) *ExplainService {
+	s.parent = parent
+	return s
+}
+
+// Preference specifies the node or shard the operation should be performed on (default: random).
+func (s *ExplainService) Preference(preference string) *ExplainService {
+	s.preference = preference
+	return s
+}
+
+// XSource is true or false to return the _source field or not, or a list of fields to return.
+func (s *ExplainService) XSource(xSource ...string) *ExplainService {
+	s.xSource = append(s.xSource, xSource...)
+	return s
+}
+
+// Query sets a query definition using the Query DSL.
+func (s *ExplainService) Query(query Query) *ExplainService {
+	src, err := query.Source()
+	if err != nil {
+		// Do nothing in case of an error
+		return s
+	}
+	body := make(map[string]interface{})
+	body["query"] = src
+	s.bodyJson = body
+	return s
+}
+
+// BodyJson sets the query definition using the Query DSL.
+func (s *ExplainService) BodyJson(body interface{}) *ExplainService {
+	s.bodyJson = body
+	return s
+}
+
+// BodyString sets the query definition using the Query DSL as a string.
+func (s *ExplainService) BodyString(body string) *ExplainService {
+	s.bodyString = body
+	return s
+}
+
+// buildURL builds the URL for the operation.
+func (s *ExplainService) buildURL() (string, url.Values, error) {
+	// Build URL
+	var path string
+	var err error
+
+	if s.typ == "" || s.typ == "_doc" {
+		path, err = uritemplates.Expand("/{index}/_explain/{id}", map[string]string{
+			"id":    s.id,
+			"index": s.index,
+		})
+	} else {
+		path, err = uritemplates.Expand("/{index}/{type}/{id}/_explain", map[string]string{
+			"id":    s.id,
+			"index": s.index,
+			"type":  s.typ,
+		})
+	}
+	if err != nil {
+		return "", url.Values{}, err
+	}
+
+	// Add query string parameters
+	params := url.Values{}
+	if v := s.pretty; v != nil {
+		params.Set("pretty", fmt.Sprint(*v))
+	}
+	if v := s.human; v != nil {
+		params.Set("human", fmt.Sprint(*v))
+	}
+	if v := s.errorTrace; v != nil {
+		params.Set("error_trace", fmt.Sprint(*v))
+	}
+	if len(s.filterPath) > 0 {
+		params.Set("filter_path", strings.Join(s.filterPath, ","))
+	}
+	if len(s.xSource) > 0 {
+		params.Set("_source", strings.Join(s.xSource, ","))
+	}
+	if s.defaultOperator != "" {
+		params.Set("default_operator", s.defaultOperator)
+	}
+	if s.parent != "" {
+		params.Set("parent", s.parent)
+	}
+	if s.preference != "" {
+		params.Set("preference", s.preference)
+	}
+	if s.source != "" {
+		params.Set("source", s.source)
+	}
+	if len(s.xSourceExclude) > 0 {
+		params.Set("_source_excludes", strings.Join(s.xSourceExclude, ","))
+	}
+	if s.lenient != nil {
+		params.Set("lenient", fmt.Sprintf("%v", *s.lenient))
+	}
+	if s.q != "" {
+		params.Set("q", s.q)
+	}
+	if s.routing != "" {
+		params.Set("routing", s.routing)
+	}
+	if len(s.fields) > 0 {
+		params.Set("fields", strings.Join(s.fields, ","))
+	}
+	if s.lowercaseExpandedTerms != nil {
+		params.Set("lowercase_expanded_terms", fmt.Sprintf("%v", *s.lowercaseExpandedTerms))
+	}
+	if len(s.xSourceInclude) > 0 {
+		params.Set("_source_includes", strings.Join(s.xSourceInclude, ","))
+	}
+	if s.analyzeWildcard != nil {
+		params.Set("analyze_wildcard", fmt.Sprintf("%v", *s.analyzeWildcard))
+	}
+	if s.analyzer != "" {
+		params.Set("analyzer", s.analyzer)
+	}
+	if s.df != "" {
+		params.Set("df", s.df)
+	}
+	return path, params, nil
+}
+
+// Validate checks if the operation is valid.
+func (s *ExplainService) Validate() error {
+	var invalid []string
+	if s.index == "" {
+		invalid = append(invalid, "Index")
+	}
+	if s.typ == "" {
+		invalid = append(invalid, "Type")
+	}
+	if s.id == "" {
+		invalid = append(invalid, "Id")
+	}
+	if len(invalid) > 0 {
+		return fmt.Errorf("missing required fields: %v", invalid)
+	}
+	return nil
+}
+
+// Do executes the operation.
+func (s *ExplainService) Do(ctx context.Context) (*ExplainResponse, error) {
+	// Check pre-conditions
+	if err := s.Validate(); err != nil {
+		return nil, err
+	}
+
+	// Get URL for request
+	path, params, err := s.buildURL()
+	if err != nil {
+		return nil, err
+	}
+
+	// Setup HTTP request body
+	var body interface{}
+	if s.bodyJson != nil {
+		body = s.bodyJson
+	} else {
+		body = s.bodyString
+	}
+
+	// Get HTTP response
+	res, err := s.client.PerformRequest(ctx, PerformRequestOptions{
+		Method:  "GET",
+		Path:    path,
+		Params:  params,
+		Body:    body,
+		Headers: s.headers,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// Return operation response
+	ret := new(ExplainResponse)
+	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+// ExplainResponse is the response of ExplainService.Do.
+type ExplainResponse struct {
+	Index       string                 `json:"_index"`
+	Type        string                 `json:"_type"`
+	Id          string                 `json:"_id"`
+	Matched     bool                   `json:"matched"`
+	Explanation map[string]interface{} `json:"explanation"`
+}