Method QueryRestrictedJoinAllowed

roomserver/internal/query/query.go:770–895

nolint:gocyclo

(ctx context.Context, req *api.QueryRestrictedJoinAllowedRequest, res *api.QueryRestrictedJoinAllowedResponse)

// nolint:gocyclo
func (r *Queryer) QueryRestrictedJoinAllowed(ctx context.Context, req *api.QueryRestrictedJoinAllowedRequest, res *api.QueryRestrictedJoinAllowedResponse) error {
	// Look up if we know anything about the room. If it doesn't exist
	// or is a stub entry then we can't do anything.
	roomInfo, err := r.DB.RoomInfo(ctx, req.RoomID)
	if err != nil {
		return fmt.Errorf("r.DB.RoomInfo: %w", err)
	}
	if roomInfo == nil || roomInfo.IsStub() {
		return nil // fmt.Errorf("room %q doesn't exist or is stub room", req.RoomID)
	}
	// If the room version doesn't allow restricted joins then don't
	// try to process any further.
	allowRestrictedJoins, err := roomInfo.RoomVersion.MayAllowRestrictedJoinsInEventAuth()
	if err != nil {
		return fmt.Errorf("roomInfo.RoomVersion.AllowRestrictedJoinsInEventAuth: %w", err)
	} else if !allowRestrictedJoins {
		return nil
	}
	// Start off by populating the "resident" flag in the response. If we
	// come across any rooms in the request that are missing, we will unset
	// the flag.
	res.Resident = true
	// Get the join rules to work out if the join rule is "restricted".
	joinRulesEvent, err := r.DB.GetStateEvent(ctx, req.RoomID, gomatrixserverlib.MRoomJoinRules, "")
	if err != nil {
		return fmt.Errorf("r.DB.GetStateEvent: %w", err)
	}
	if joinRulesEvent == nil {
		return nil
	}
	var joinRules gomatrixserverlib.JoinRuleContent
	if err = json.Unmarshal(joinRulesEvent.Content(), &joinRules); err != nil {
		return fmt.Errorf("json.Unmarshal: %w", err)
	}
	// If the join rule isn't "restricted" then there's nothing more to do.
	res.Restricted = joinRules.JoinRule == gomatrixserverlib.Restricted
	if !res.Restricted {
		return nil
	}
	// If the user is already invited to the room then the join is allowed
	// but we don't specify an authorised via user, since the event auth
	// will allow the join anyway.
	var pending bool
	if pending, _, _, err = helpers.IsInvitePending(ctx, r.DB, req.RoomID, req.UserID); err != nil {
		return fmt.Errorf("helpers.IsInvitePending: %w", err)
	} else if pending {
		res.Allowed = true
		return nil
	}
	// We need to get the power levels content so that we can determine which
	// users in the room are entitled to issue invites. We need to use one of
	// these users as the authorising user.
	powerLevelsEvent, err := r.DB.GetStateEvent(ctx, req.RoomID, gomatrixserverlib.MRoomPowerLevels, "")
	if err != nil {
		return fmt.Errorf("r.DB.GetStateEvent: %w", err)
	}
	var powerLevels gomatrixserverlib.PowerLevelContent
	if err = json.Unmarshal(powerLevelsEvent.Content(), &powerLevels); err != nil {