[MM-27535] User invite limits for MM Cloud (#15197)

* Add a config for MM User Limit

* Adding graceful errors for if an administrator invites people passed their user limit

* Including changed vendor files

* Adding unit test

* Fix a bug

* Push up working tests (Thanks Joram)

* Add more cases, clean up logs in code

* One more case

* Refactoring based on PR comments

* Updating i18n

* Some changes based on PR review

* Remove a comment

* Bring back some translations that were somehow removed

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

app/app_iface.go

@@ -537,6 +537,7 @@ type AppIface interface {
 	GetEmojiByName(emojiName string) (*model.Emoji, *model.AppError)
 	GetEmojiImage(emojiId string) ([]byte, string, *model.AppError)
 	GetEmojiList(page, perPage int, sort string) ([]*model.Emoji, *model.AppError)
+	GetErrorListForEmailsOverLimit(emailList []string, cloudUserLimit int64) ([]string, []*model.EmailInviteWithError, *model.AppError)
 	GetFile(fileId string) ([]byte, *model.AppError)
 	GetFileInfo(fileId string) (*model.FileInfo, *model.AppError)
 	GetFileInfos(page, perPage int, opt *model.GetFileInfosOptions) ([]*model.FileInfo, *model.AppError)

app/opentracing/opentracing_layer.go

@@ -5069,6 +5069,28 @@ func (a *OpenTracingAppLayer) GetEnvironmentConfig() map[string]interface{} {
 	return resultVar0
 }
 
+func (a *OpenTracingAppLayer) GetErrorListForEmailsOverLimit(emailList []string, cloudUserLimit int64) ([]string, []*model.EmailInviteWithError, *model.AppError) {
+	origCtx := a.ctx
+	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.GetErrorListForEmailsOverLimit")
+
+	a.ctx = newCtx
+	a.app.Srv().Store.SetContext(newCtx)
+	defer func() {
+		a.app.Srv().Store.SetContext(origCtx)
+		a.ctx = origCtx
+	}()
+
+	defer span.Finish()
+	resultVar0, resultVar1, resultVar2 := a.app.GetErrorListForEmailsOverLimit(emailList, cloudUserLimit)
+
+	if resultVar2 != nil {
+		span.LogFields(spanlog.Error(resultVar2))
+		ext.Error.Set(span, true)
+	}
+
+	return resultVar0, resultVar1, resultVar2
+}
+
 func (a *OpenTracingAppLayer) GetFile(fileId string) ([]byte, *model.AppError) {
 	origCtx := a.ctx
 	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.GetFile")

app/team.go

@@ -1127,6 +1127,47 @@ func (a *App) prepareInviteNewUsersToTeam(teamId, senderId string) (*model.User,
 	return user, team, nil
 }
 
+func genEmailInviteWithErrorList(emailList []string) []*model.EmailInviteWithError {
+	invitesNotSent := make([]*model.EmailInviteWithError, len(emailList))
+	for i := range emailList {
+		invite := &model.EmailInviteWithError{
+			Email: emailList[i],
+			Error: model.NewAppError("inviteUsersToTeam", "api.team.invite_members.limit_reached.app_error", map[string]interface{}{"Addresses": emailList[i]}, "", http.StatusBadRequest),
+		}
+		invitesNotSent[i] = invite
+	}
+	return invitesNotSent
+}
+
+func (a *App) GetErrorListForEmailsOverLimit(emailList []string, cloudUserLimit int64) ([]string, []*model.EmailInviteWithError, *model.AppError) {
+	var invitesNotSent []*model.EmailInviteWithError
+	if cloudUserLimit <= 0 {
+		return emailList, invitesNotSent, nil
+	}
+	systemUserCount, _ := a.Srv().Store.User().Count(model.UserCountOptions{})
+	remainingUsers := cloudUserLimit - systemUserCount
+	if remainingUsers <= 0 {
+		// No remaining users so all fail
+		invitesNotSent = genEmailInviteWithErrorList(emailList)
+		emailList = nil
+	} else if remainingUsers < int64(len(emailList)) {
+		// Trim the email list to only invite as many users as are remaining in subscription
+		// Set graceful errors for the remaining email addresses
+		emailsAboveLimit := emailList[remainingUsers:]
+		invitesNotSent = genEmailInviteWithErrorList(emailsAboveLimit)
+		// If 1 user remaining we have to prevent 0:0 reslicing
+		if remainingUsers == 1 {
+			email := emailList[0]
+			emailList = nil
+			emailList = append(emailList, email)
+		} else {
+			emailList = emailList[:(remainingUsers - 1)]
+		}
+	}
+
+	return emailList, invitesNotSent, nil
+}
+
 func (a *App) InviteNewUsersToTeamGracefully(emailList []string, teamId, senderId string) ([]*model.EmailInviteWithError, *model.AppError) {
 	if !*a.Config().ServiceSettings.EnableEmailInvitations {
 		return nil, model.NewAppError("InviteNewUsersToTeam", "api.team.invite_members.disabled.app_error", nil, "", http.StatusNotImplemented)
@@ -1136,7 +1177,6 @@ func (a *App) InviteNewUsersToTeamGracefully(emailList []string, teamId, senderI
 		err := model.NewAppError("InviteNewUsersToTeam", "api.team.invite_members.no_one.app_error", nil, "", http.StatusBadRequest)
 		return nil, err
 	}
-
 	user, team, err := a.prepareInviteNewUsersToTeam(teamId, senderId)
 	if err != nil {
 		return nil, err