MM-6992 Added highlighting to elasticsearch results (#8861)

* MM-6992 Added highlighting to elasticsearch results

* Added a unique type for post search matches

* Fixed Elasticsearch matches not being sent through API

6 files changed, 65 insertions, 8 deletions

diff --git a/api4/post.go b/api4/post.go
index 68c1967ff..27ecd1584 100644
--- a/api4/post.go
+++ b/api4/post.go
@@ -341,7 +341,7 @@ func searchPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	startTime := time.Now()
 
-	posts, err := c.App.SearchPostsInTeam(terms, c.Session.UserId, c.Params.TeamId, isOrSearch)
+	results, err := c.App.SearchPostsInTeam(terms, c.Session.UserId, c.Params.TeamId, isOrSearch)
 
 	elapsedTime := float64(time.Since(startTime)) / float64(time.Second)
 	metrics := c.App.Metrics
@@ -355,8 +355,10 @@ func searchPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	results = model.MakePostSearchResults(c.App.PostListWithProxyAddedToImageURLs(results.PostList), results.Matches)
+
 	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
-	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(posts).ToJson()))
+	w.Write([]byte(results.ToJson()))
 }
 
 func updatePost(c *Context, w http.ResponseWriter, r *http.Request) {
diff --git a/app/post.go b/app/post.go
index 4f4c6f65c..e24018995 100644
--- a/app/post.go
+++ b/app/post.go
@@ -621,7 +621,7 @@ func (a *App) DeletePostFiles(post *model.Post) {
 	}
 }
 
-func (a *App) SearchPostsInTeam(terms string, userId string, teamId string, isOrSearch bool) (*model.PostList, *model.AppError) {
+func (a *App) SearchPostsInTeam(terms string, userId string, teamId string, isOrSearch bool) (*model.PostSearchResults, *model.AppError) {
 	paramsList := model.ParseSearchParams(terms)
 
 	esInterface := a.Elasticsearch
@@ -656,7 +656,7 @@ func (a *App) SearchPostsInTeam(terms string, userId string, teamId string, isOr
 
 		// If the processed search params are empty, return empty search results.
 		if len(finalParamsList) == 0 {
-			return model.NewPostList(), nil
+			return model.MakePostSearchResults(model.NewPostList(), nil), nil
 		}
 
 		// We only allow the user to search in channels they are a member of.
@@ -666,7 +666,7 @@ func (a *App) SearchPostsInTeam(terms string, userId string, teamId string, isOr
 			return nil, err
 		}
 
-		postIds, err := a.Elasticsearch.SearchPosts(userChannels, finalParamsList)
+		postIds, matches, err := a.Elasticsearch.SearchPosts(userChannels, finalParamsList)
 		if err != nil {
 			return nil, err
 		}
@@ -684,7 +684,7 @@ func (a *App) SearchPostsInTeam(terms string, userId string, teamId string, isOr
 			}
 		}
 
-		return postList, nil
+		return model.MakePostSearchResults(postList, matches), nil
 	} else {
 		if !*a.Config().ServiceSettings.EnablePostSearch {
 			return nil, model.NewAppError("SearchPostsInTeam", "store.sql_post.search.disabled", nil, fmt.Sprintf("teamId=%v userId=%v", teamId, userId), http.StatusNotImplemented)
@@ -712,7 +712,7 @@ func (a *App) SearchPostsInTeam(terms string, userId string, teamId string, isOr
 
 		posts.SortByCreateAt()
 
-		return posts, nil
+		return model.MakePostSearchResults(posts, nil), nil
 	}
 }
 
diff --git a/einterfaces/elasticsearch.go b/einterfaces/elasticsearch.go
index 5582fd4e8..1b7444b2b 100644
--- a/einterfaces/elasticsearch.go
+++ b/einterfaces/elasticsearch.go
@@ -12,7 +12,7 @@ import (
 type ElasticsearchInterface interface {
 	Start() *model.AppError
 	IndexPost(post *model.Post, teamId string) *model.AppError
-	SearchPosts(channels *model.ChannelList, searchParams []*model.SearchParams) ([]string, *model.AppError)
+	SearchPosts(channels *model.ChannelList, searchParams []*model.SearchParams) ([]string, model.PostSearchMatches, *model.AppError)
 	DeletePost(post *model.Post) *model.AppError
 	TestConfig(cfg *model.Config) *model.AppError
 	PurgeIndexes() *model.AppError
diff --git a/i18n/en.json b/i18n/en.json
index 6828740fc..4b1849ccc 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -4279,6 +4279,10 @@
     "translation": "Search failed to complete"
   },
   {
+    "id": "ent.elasticsearch.search_posts.parse_matches_failed",
+    "translation": "Failed to parse search result matches"
+  },
+  {
     "id": "ent.elasticsearch.search_posts.unmarshall_post_failed",
     "translation": "Failed to decode search results"
   },
diff --git a/model/client4.go b/model/client4.go
index f5a856835..3a93a9541 100644
--- a/model/client4.go
+++ b/model/client4.go
@@ -2127,6 +2127,17 @@ func (c *Client4) SearchPosts(teamId string, terms string, isOrSearch bool) (*Po
 	}
 }
 
+// SearchPosts returns any posts with matching terms string, including .
+func (c *Client4) SearchPostsWithMatches(teamId string, terms string, isOrSearch bool) (*PostSearchResults, *Response) {
+	requestBody := map[string]interface{}{"terms": terms, "is_or_search": isOrSearch}
+	if r, err := c.DoApiPost(c.GetTeamRoute(teamId)+"/posts/search", StringInterfaceToJson(requestBody)); err != nil {
+		return nil, BuildErrorResponse(r, err)
+	} else {
+		defer closeBody(r)
+		return PostSearchResultsFromJson(r.Body), BuildResponse(r)
+	}
+}
+
 // DoPostAction performs a post action.
 func (c *Client4) DoPostAction(postId, actionId string) (bool, *Response) {
 	if r, err := c.DoApiPost(c.GetPostRoute(postId)+"/actions/"+actionId, ""); err != nil {
diff --git a/model/post_search_results.go b/model/post_search_results.go
new file mode 100644
index 000000000..2317f1831
--- /dev/null
+++ b/model/post_search_results.go
@@ -0,0 +1,40 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"encoding/json"
+	"io"
+)
+
+type PostSearchMatches map[string][]string
+
+type PostSearchResults struct {
+	*PostList
+	Matches PostSearchMatches `json:"matches"`
+}
+
+func MakePostSearchResults(posts *PostList, matches PostSearchMatches) *PostSearchResults {
+	return &PostSearchResults{
+		posts,
+		matches,
+	}
+}
+
+func (o *PostSearchResults) ToJson() string {
+	copy := *o
+	copy.PostList.StripActionIntegrations()
+	b, err := json.Marshal(&copy)
+	if err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func PostSearchResultsFromJson(data io.Reader) *PostSearchResults {
+	var o *PostSearchResults
+	json.NewDecoder(data).Decode(&o)
+	return o
+}