MM-14753: Verifies that user can join teams and channels in spite of group constraints. (#10529)

* MM-147753: Verifies that users are allowed to be members of a team or a channel, based on group constraints, prior to allowing the API to add them.

* MM-14753: Allow methods to return meaningful results for deleted teams or channels.

* MM-14753: Renames methods to differentiate from permissions and other team and channel restrictions.

* MM-14753: Only check if users are team/channel members if team/channel is group constrained.

* MM-14753: Updates test function names.

* MM-14753: Changes a few method signatures.

* MM-14753: Small refactor and adds missing returns.

* MM-14753: Changes method names from Get* to Filter* name prefixes.

* MM-14753: Renames error variables.

* MM-14753: Updates method names for consistency with join table names.

* MM-14753: Adds case for non AppError return.

* Update i18n/en.json

store/sqlstore/user_store.go

@@ -1536,3 +1536,83 @@ func (us SqlUserStore) GetUsersBatchForIndexing(startTime, endTime int64, limit
 		result.Data = usersForIndexing
 	})
 }
+
+func (us SqlUserStore) GetTeamGroupUsers(teamID string) store.StoreChannel {
+	return store.Do(func(result *store.StoreResult) {
+		query := us.usersQuery.
+			Where(`Id IN (
+				SELECT
+					GroupMembers.UserId
+				FROM
+					Teams
+					JOIN GroupTeams ON GroupTeams.TeamId = Teams.Id
+					JOIN UserGroups ON UserGroups.Id = GroupTeams.GroupId
+					JOIN GroupMembers ON GroupMembers.GroupId = UserGroups.Id
+				WHERE
+					Teams.Id = ?
+					AND GroupTeams.DeleteAt = 0
+					AND UserGroups.DeleteAt = 0
+					AND GroupMembers.DeleteAt = 0
+				GROUP BY
+					GroupMembers.UserId
+			)`, teamID)
+
+		queryString, args, err := query.ToSql()
+		if err != nil {
+			result.Err = model.NewAppError("SqlUserStore.UsersPermittedToTeam", "store.sql_user.app_error", nil, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		var users []*model.User
+		if _, err := us.GetReplica().Select(&users, queryString, args...); err != nil {
+			result.Err = model.NewAppError("SqlUserStore.UsersPermittedToTeam", "store.sql_user.get_profiles.app_error", nil, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		for _, u := range users {
+			u.Sanitize(map[string]bool{})
+		}
+
+		result.Data = users
+	})
+}
+
+func (us SqlUserStore) GetChannelGroupUsers(channelID string) store.StoreChannel {
+	return store.Do(func(result *store.StoreResult) {
+		query := us.usersQuery.
+			Where(`Id IN (
+				SELECT
+					GroupMembers.UserId
+				FROM
+					Channels
+					JOIN GroupChannels ON GroupChannels.ChannelId = Channels.Id
+					JOIN UserGroups ON UserGroups.Id = GroupChannels.GroupId
+					JOIN GroupMembers ON GroupMembers.GroupId = UserGroups.Id
+				WHERE
+					Channels.Id = ?
+					AND GroupChannels.DeleteAt = 0
+					AND UserGroups.DeleteAt = 0
+					AND GroupMembers.DeleteAt = 0
+				GROUP BY
+					GroupMembers.UserId
+			)`, channelID)
+
+		queryString, args, err := query.ToSql()
+		if err != nil {
+			result.Err = model.NewAppError("SqlUserStore.GetChannelGroupUsers", "store.sql_user.app_error", nil, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		var users []*model.User
+		if _, err := us.GetReplica().Select(&users, queryString, args...); err != nil {
+			result.Err = model.NewAppError("SqlUserStore.GetChannelGroupUsers", "store.sql_user.get_profiles.app_error", nil, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		for _, u := range users {
+			u.Sanitize(map[string]bool{})
+		}
+
+		result.Data = users
+	})
+}