[MM-44084] Feature: Top threads insights (#20195)

* Add route endpoints, model, store functions, and tests for top threads

* Run make store-layers

* Make the following changes

 - Fix top user threads query
 - Fix passing parameters in api4/insights.go to handler in app
 - Add top user threads test

* Add post-message, user_id, participants information to insights results

* model.TopThread.UserID -> model.TopThread.UserId, for compatibility with MySQL

* Rename name -> channel_name

* Add user information to response

* Link post in response, filter out deleted root posts from top threads

* Handle thread delete cases, add app tests for threads insights

* lint: fix typo

* lint: rename asserts

* lint: require.nil -> require.NoError

* Add integration tests for thread insights

* Add embeds and images to top posts

* Add license checks for top threads endpoints

* Query users in batch to populate post-creator

* Make the following changes

 - Add license to test server in api4/
 - Add tests for threads insights
    - top team threads shouldn't include threads from other teams, DMs
    - Test duration constraint
    - Pagination testing for top threads in model/insights_test.go

* Add i18n-extract

* i18n fixes

* Add username, nickname to user_information

* Hide message, user_id, post_id, reply_count in depth=1 of top threads response

* Fix tests using response.reply_count to use response.post.reply_count

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/insights.go

@@ -20,6 +20,10 @@ func (api *API) InitInsights() {
 	// Channels
 	api.BaseRoutes.InsightsForTeam.Handle("/channels", api.APISessionRequired(minimumProfessionalLicense(rejectGuests(getTopChannelsForTeamSince)))).Methods("GET")
 	api.BaseRoutes.InsightsForUser.Handle("/channels", api.APISessionRequired(minimumProfessionalLicense(rejectGuests(getTopChannelsForUserSince)))).Methods("GET")
+
+	// Threads
+	api.BaseRoutes.InsightsForTeam.Handle("/threads", api.APISessionRequired(requireLicense(getTopThreadsForTeamSince))).Methods("GET")
+	api.BaseRoutes.InsightsForUser.Handle("/threads", api.APISessionRequired(requireLicense(getTopThreadsForUserSince))).Methods("GET")
 }
 
 // Top Reactions
@@ -227,6 +231,116 @@ func getTopChannelsForUserSince(c *Context, w http.ResponseWriter, r *http.Reque
 	w.Write(js)
 }
 
+// Top Threads
+func getTopThreadsForTeamSince(c *Context, w http.ResponseWriter, r *http.Request) {
+	c.RequireTeamId()
+	if c.Err != nil {
+		return
+	}
+
+	team, err := c.App.GetTeam(c.Params.TeamId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	// license check
+	lic := c.App.Srv().License()
+	if lic.SkuShortName != model.LicenseShortSkuProfessional && lic.SkuShortName != model.LicenseShortSkuEnterprise {
+		c.Err = model.NewAppError("", "api.insights.license_error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	// restrict guests and users with no access to team
+	user, err := c.App.GetUser(c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	if !c.App.SessionHasPermissionToTeam(*c.AppContext.Session(), team.Id, model.PermissionViewTeam) || user.IsGuest() {
+		c.SetPermissionError(model.PermissionViewTeam)
+		return
+	}
+
+	startTime := model.StartOfDayForTimeRange(c.Params.TimeRange, user.GetTimezoneLocation())
+
+	topThreads, err := c.App.GetTopThreadsForTeamSince(c.Params.TeamId, c.AppContext.Session().UserId, &model.InsightsOpts{
+		StartUnixMilli: startTime.UnixMilli(),
+		Page:           c.Params.Page,
+		PerPage:        c.Params.PerPage,
+	})
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	js, jsonErr := json.Marshal(topThreads)
+	if jsonErr != nil {
+		c.Err = model.NewAppError("getTopThreadsForTeamSince", "api.marshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Write(js)
+}
+
+func getTopThreadsForUserSince(c *Context, w http.ResponseWriter, r *http.Request) {
+	c.Params.TeamId = r.URL.Query().Get("team_id")
+
+	// restrict guests and users with no access to team
+	user, err := c.App.GetUser(c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+	// TeamId is an optional parameter
+	if c.Params.TeamId != "" {
+		if !model.IsValidId(c.Params.TeamId) {
+			c.SetInvalidURLParam("team_id")
+			return
+		}
+
+		team, teamErr := c.App.GetTeam(c.Params.TeamId)
+		if teamErr != nil {
+			c.Err = teamErr
+			return
+		}
+
+		// license check
+		lic := c.App.Srv().License()
+		if lic.SkuShortName != model.LicenseShortSkuProfessional && lic.SkuShortName != model.LicenseShortSkuEnterprise {
+			c.Err = model.NewAppError("", "api.insights.license_error", nil, "", http.StatusNotImplemented)
+			return
+		}
+
+		if !c.App.SessionHasPermissionToTeam(*c.AppContext.Session(), team.Id, model.PermissionViewTeam) || user.IsGuest() {
+			c.SetPermissionError(model.PermissionViewTeam)
+			return
+		}
+	}
+
+	startTime := model.StartOfDayForTimeRange(c.Params.TimeRange, user.GetTimezoneLocation())
+
+	topThreads, err := c.App.GetTopThreadsForUserSince(c.Params.TeamId, c.AppContext.Session().UserId, &model.InsightsOpts{
+		StartUnixMilli: startTime.UnixMilli(),
+		Page:           c.Params.Page,
+		PerPage:        c.Params.PerPage,
+	})
+
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	js, jsonErr := json.Marshal(topThreads)
+	if jsonErr != nil {
+		c.Err = model.NewAppError("getTopThreadsForUserSince", "api.marshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	w.Write(js)
+}
+
 // postCountByDurationViewModel expects a list of channels that are pre-authorized for the given user to view.
 func postCountByDurationViewModel(app app.AppIface, topChannelList *model.TopChannelList, startTime *time.Time, timeRange string, userID *string, location *time.Location) (model.ChannelPostCountByDuration, *model.AppError) {
 	if len(topChannelList.Items) == 0 {