[feature] support canceling scheduled tasks, some federation API performance improvements (#2329)

6 files changed, 146 insertions, 292 deletions

diff --git a/internal/federation/federatingdb/create.go b/internal/federation/federatingdb/create.go
index 14e846b15..0fb459190 100644
--- a/internal/federation/federatingdb/create.go
+++ b/internal/federation/federatingdb/create.go
@@ -24,7 +24,6 @@ import (
 	"strings"
 
 	"codeberg.org/gruf/go-logger/v2/level"
-	"github.com/superseriousbusiness/activity/pub"
 	"github.com/superseriousbusiness/activity/streams/vocab"
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
@@ -137,22 +136,37 @@ func (f *federatingDB) activityCreate(
 		return gtserror.Newf("could not convert asType %T to ActivityStreamsCreate", asType)
 	}
 
-	for _, object := range ap.ExtractObjects(create) {
-		// Try to get object as vocab.Type,
-		// else skip handling (likely) IRI.
-		objType := object.GetType()
-		if objType == nil {
-			continue
-		}
+	var errs gtserror.MultiError
+
+	// Extract objects from create activity.
+	objects := ap.ExtractObjects(create)
+
+	// Extract Statusables from objects slice (this must be
+	// done AFTER extracting options due to how AS typing works).
+	statusables, objects := ap.ExtractStatusables(objects)
 
-		if statusable, ok := ap.ToStatusable(objType); ok {
-			return f.createStatusable(ctx, statusable, receivingAccount, requestingAccount)
+	for _, statusable := range statusables {
+		// Check if this is a forwarded object, i.e. did
+		// the account making the request also create this?
+		forwarded := !isSender(statusable, requestingAccount)
+
+		// Handle create event for this statusable.
+		if err := f.createStatusable(ctx,
+			receivingAccount,
+			requestingAccount,
+			statusable,
+			forwarded,
+		); err != nil {
+			errs.Appendf("error creating statusable: %w", err)
 		}
+	}
 
-		// TODO: handle CREATE of other types?
+	if len(objects) > 0 {
+		// Log any unhandled objects after filtering for debug purposes.
+		log.Debugf(ctx, "unhandled CREATE types: %v", typeNames(objects))
 	}
 
-	return nil
+	return errs.Combine()
 }
 
 // createStatusable handles a Create activity for a Statusable.
@@ -161,88 +175,36 @@ func (f *federatingDB) activityCreate(
 // the processor for further asynchronous processing.
 func (f *federatingDB) createStatusable(
 	ctx context.Context,
+	receiver *gtsmodel.Account,
+	requester *gtsmodel.Account,
 	statusable ap.Statusable,
-	receivingAccount *gtsmodel.Account,
-	requestingAccount *gtsmodel.Account,
+	forwarded bool,
 ) error {
-	// Statusable must have an attributedTo.
-	attrToProp := statusable.GetActivityStreamsAttributedTo()
-	if attrToProp == nil {
-		return gtserror.Newf("statusable had no attributedTo")
-	}
-
-	// Statusable must have an ID.
-	idProp := statusable.GetJSONLDId()
-	if idProp == nil || !idProp.IsIRI() {
-		return gtserror.Newf("statusable had no id, or id was not a URI")
-	}
-
-	statusableURI := idProp.GetIRI()
-
-	// Check if we have a forward. In other words, was the
-	// statusable posted to our inbox by at least one actor
-	// who actually created it, or are they forwarding it?
-	forward := true
-	for iter := attrToProp.Begin(); iter != attrToProp.End(); iter = iter.Next() {
-		actorURI, err := pub.ToId(iter)
-		if err != nil {
-			return gtserror.Newf("error extracting id from attributedTo entry: %w", err)
-		}
-
-		if requestingAccount.URI == actorURI.String() {
-			// The actor who posted this statusable to our inbox is
-			// (one of) its creator(s), so this is not a forward.
-			forward = false
-			break
-		}
-	}
-
-	// Check if we already have a status entry
-	// for this statusable, based on the ID/URI.
-	statusableURIStr := statusableURI.String()
-	status, err := f.state.DB.GetStatusByURI(ctx, statusableURIStr)
-	if err != nil && !errors.Is(err, db.ErrNoEntries) {
-		return gtserror.Newf("db error checking existence of status %s: %w", statusableURIStr, err)
-	}
-
-	if status != nil {
-		// We already had this status in the db, no need for further action.
-		log.Trace(ctx, "status already exists: %s", statusableURIStr)
-		return nil
-	}
-
 	// If we do have a forward, we should ignore the content
 	// and instead deref based on the URI of the statusable.
 	//
 	// In other words, don't automatically trust whoever sent
 	// this status to us, but fetch the authentic article from
 	// the server it originated from.
-	if forward {
-		// Pass the statusable URI (APIri) into the processor worker
-		// and do the rest of the processing asynchronously.
+	if forwarded {
+		// Pass the statusable URI (APIri) into the processor
+		// worker and do the rest of the processing asynchronously.
 		f.state.Workers.EnqueueFediAPI(ctx, messages.FromFediAPI{
 			APObjectType:     ap.ObjectNote,
 			APActivityType:   ap.ActivityCreate,
-			APIri:            statusableURI,
+			APIri:            ap.GetJSONLDId(statusable),
 			APObjectModel:    nil,
 			GTSModel:         nil,
-			ReceivingAccount: receivingAccount,
+			ReceivingAccount: receiver,
 		})
 		return nil
 	}
 
-	// This is a non-forwarded status we can trust the requester on,
-	// convert this provided statusable data to a useable gtsmodel status.
-	status, err = f.converter.ASStatusToStatus(ctx, statusable)
-	if err != nil {
-		return gtserror.Newf("error converting statusable to status: %w", err)
-	}
-
 	// Check whether we should accept this new status.
 	accept, err := f.shouldAcceptStatusable(ctx,
-		receivingAccount,
-		requestingAccount,
-		status,
+		receiver,
+		requester,
+		statusable,
 	)
 	if err != nil {
 		return gtserror.Newf("error checking status acceptibility: %w", err)
@@ -258,65 +220,52 @@ func (f *federatingDB) createStatusable(
 		return nil
 	}
 
-	// ID the new status based on the time it was created.
-	status.ID, err = id.NewULIDFromTime(status.CreatedAt)
-	if err != nil {
-		return err
-	}
-
-	// Put this newly parsed status in the database.
-	if err := f.state.DB.PutStatus(ctx, status); err != nil {
-		if errors.Is(err, db.ErrAlreadyExists) {
-			// The status already exists in the database, which
-			// means we've already processed it and some race
-			// condition means we didn't catch it yet. We can
-			// just return nil here and be done with it.
-			return nil
-		}
-		return gtserror.Newf("db error inserting status: %w", err)
-	}
-
 	// Do the rest of the processing asynchronously. The processor
 	// will handle inserting/updating + further dereferencing the status.
 	f.state.Workers.EnqueueFediAPI(ctx, messages.FromFediAPI{
 		APObjectType:     ap.ObjectNote,
 		APActivityType:   ap.ActivityCreate,
 		APIri:            nil,
+		GTSModel:         nil,
 		APObjectModel:    statusable,
-		GTSModel:         status,
-		ReceivingAccount: receivingAccount,
+		ReceivingAccount: receiver,
 	})
 
 	return nil
 }
 
-func (f *federatingDB) shouldAcceptStatusable(ctx context.Context, receiver *gtsmodel.Account, requester *gtsmodel.Account, status *gtsmodel.Status) (bool, error) {
+func (f *federatingDB) shouldAcceptStatusable(ctx context.Context, receiver *gtsmodel.Account, requester *gtsmodel.Account, statusable ap.Statusable) (bool, error) {
 	host := config.GetHost()
 	accountDomain := config.GetAccountDomain()
 
 	// Check whether status mentions the receiver,
 	// this is the quickest check so perform it first.
-	// Prefer checking using mention Href, fall back to Name.
-	for _, mention := range status.Mentions {
-		targetURI := mention.TargetAccountURI
-		nameString := mention.NameString
-
-		if targetURI != "" {
-			if targetURI == receiver.URI || targetURI == receiver.URL {
-				// Target URI or URL match;
-				// receiver is mentioned.
+	mentions, _ := ap.ExtractMentions(statusable)
+	for _, mention := range mentions {
+
+		// Extract placeholder mention vars.
+		accURI := mention.TargetAccountURI
+		name := mention.NameString
+
+		switch {
+		case accURI != "":
+			if accURI == receiver.URI ||
+				accURI == receiver.URL {
+				// Mention target is receiver,
+				// they are mentioned in status.
 				return true, nil
 			}
-		} else if nameString != "" {
-			username, domain, err := util.ExtractNamestringParts(nameString)
+
+		case accURI == "" && name != "":
+			// Only a name was provided, extract the user@domain parts.
+			user, domain, err := util.ExtractNamestringParts(name)
 			if err != nil {
-				return false, gtserror.Newf("error checking if mentioned: %w", err)
+				return false, gtserror.Newf("error extracting mention name parts: %w", err)
 			}
 
-			if (domain == host || domain == accountDomain) &&
-				strings.EqualFold(username, receiver.Username) {
-				// Username + domain match;
-				// receiver is mentioned.
+			// Check if the name points to our receiving local user.
+			isLocal := (domain == host || domain == accountDomain)
+			if isLocal && strings.EqualFold(user, receiver.Username) {
 				return true, nil
 			}
 		}
diff --git a/internal/federation/federatingdb/create_test.go b/internal/federation/federatingdb/create_test.go
index 6c18f5bd0..a1f1a7e18 100644
--- a/internal/federation/federatingdb/create_test.go
+++ b/internal/federation/federatingdb/create_test.go
@@ -39,6 +39,8 @@ func (suite *CreateTestSuite) TestCreateNote() {
 	ctx := createTestContext(receivingAccount, requestingAccount)
 
 	create := suite.testActivities["dm_for_zork"].Activity
+	objProp := create.GetActivityStreamsObject()
+	note := objProp.At(0).GetType().(ap.Statusable)
 
 	err := suite.federatingDB.Create(ctx, create)
 	suite.NoError(err)
@@ -47,18 +49,7 @@ func (suite *CreateTestSuite) TestCreateNote() {
 	msg := <-suite.fromFederator
 	suite.Equal(ap.ObjectNote, msg.APObjectType)
 	suite.Equal(ap.ActivityCreate, msg.APActivityType)
-
-	// shiny new status should be defined on the message
-	suite.NotNil(msg.GTSModel)
-	status := msg.GTSModel.(*gtsmodel.Status)
-
-	// status should have some expected values
-	suite.Equal(requestingAccount.ID, status.AccountID)
-	suite.Equal("@the_mighty_zork@localhost:8080 hey zork here's a new private note for you", status.Content)
-
-	// status should be in the database
-	_, err = suite.db.GetStatusByID(context.Background(), status.ID)
-	suite.NoError(err)
+	suite.Equal(note, msg.APObjectModel)
 }
 
 func (suite *CreateTestSuite) TestCreateNoteForward() {
@@ -78,7 +69,7 @@ func (suite *CreateTestSuite) TestCreateNoteForward() {
 	suite.Equal(ap.ActivityCreate, msg.APActivityType)
 
 	// nothing should be set as the model since this is a forward
-	suite.Nil(msg.GTSModel)
+	suite.Nil(msg.APObjectModel)
 
 	// but we should have a uri set
 	suite.Equal("http://example.org/users/Some_User/statuses/afaba698-5740-4e32-a702-af61aa543bc1", msg.APIri.String())
diff --git a/internal/federation/federatingdb/db.go b/internal/federation/federatingdb/db.go
index 8e98dc2f2..75ef3a2a7 100644
--- a/internal/federation/federatingdb/db.go
+++ b/internal/federation/federatingdb/db.go
@@ -24,6 +24,7 @@ import (
 	"github.com/superseriousbusiness/activity/streams/vocab"
 	"github.com/superseriousbusiness/gotosocial/internal/state"
 	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
+	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 )
 
 // DB wraps the pub.Database interface with a couple of custom functions for GoToSocial.
@@ -33,7 +34,6 @@ type DB interface {
 	Accept(ctx context.Context, accept vocab.ActivityStreamsAccept) error
 	Reject(ctx context.Context, reject vocab.ActivityStreamsReject) error
 	Announce(ctx context.Context, announce vocab.ActivityStreamsAnnounce) error
-	Question(ctx context.Context, question vocab.ActivityStreamsQuestion) error
 }
 
 // FederatingDB uses the underlying DB interface to implement the go-fed pub.Database interface.
@@ -41,13 +41,15 @@ type DB interface {
 type federatingDB struct {
 	state     *state.State
 	converter *typeutils.Converter
+	filter    *visibility.Filter
 }
 
 // New returns a DB interface using the given database and config
-func New(state *state.State, converter *typeutils.Converter) DB {
+func New(state *state.State, converter *typeutils.Converter, filter *visibility.Filter) DB {
 	fdb := federatingDB{
 		state:     state,
 		converter: converter,
+		filter:    filter,
 	}
 	return &fdb
 }
diff --git a/internal/federation/federatingdb/question.go b/internal/federation/federatingdb/question.go
deleted file mode 100644
index 85226d9ed..000000000
--- a/internal/federation/federatingdb/question.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// GoToSocial
-// Copyright (C) GoToSocial Authors admin@gotosocial.org
-// SPDX-License-Identifier: AGPL-3.0-or-later
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-package federatingdb
-
-import (
-	"context"
-
-	"github.com/superseriousbusiness/activity/streams/vocab"
-)
-
-func (f *federatingDB) Question(ctx context.Context, question vocab.ActivityStreamsQuestion) error {
-	receivingAccount, requestingAccount, internal := extractFromCtx(ctx)
-	if internal {
-		return nil // Already processed.
-	}
-	return f.createStatusable(ctx, question, receivingAccount, requestingAccount)
-}
diff --git a/internal/federation/federatingdb/update.go b/internal/federation/federatingdb/update.go
index 5d3d4a0ff..26ea81f72 100644
--- a/internal/federation/federatingdb/update.go
+++ b/internal/federation/federatingdb/update.go
@@ -19,11 +19,13 @@ package federatingdb
 
 import (
 	"context"
+	"errors"
 
 	"codeberg.org/gruf/go-logger/v2/level"
 	"github.com/superseriousbusiness/activity/streams/vocab"
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
@@ -71,18 +73,21 @@ func (f *federatingDB) updateAccountable(ctx context.Context, receivingAcct *gts
 	// Extract AP URI of the updated Accountable model.
 	idProp := accountable.GetJSONLDId()
 	if idProp == nil || !idProp.IsIRI() {
-		return gtserror.New("Accountable id prop was nil or not IRI")
+		return gtserror.New("invalid id prop")
 	}
-	updatedAcctURI := idProp.GetIRI()
 
-	// Don't try to update local accounts, it will break things.
-	if updatedAcctURI.Host == config.GetHost() {
+	// Get the account URI string for checks
+	accountURI := idProp.GetIRI()
+	accountURIStr := accountURI.String()
+
+	// Don't try to update local accounts.
+	if accountURI.Host == config.GetHost() {
 		return nil
 	}
 
-	// Ensure Accountable and requesting account are one and the same.
-	if updatedAcctURIStr := updatedAcctURI.String(); requestingAcct.URI != updatedAcctURIStr {
-		return gtserror.Newf("update for %s was requested by %s, this is not valid", updatedAcctURIStr, requestingAcct.URI)
+	// Check that update was by the account themselves.
+	if accountURIStr != requestingAcct.URI {
+		return gtserror.Newf("update for %s was not requested by owner", accountURIStr)
 	}
 
 	// Pass in to the processor the existing version of the requesting
@@ -117,15 +122,31 @@ func (f *federatingDB) updateStatusable(ctx context.Context, receivingAcct *gtsm
 		return nil
 	}
 
+	// Check if this is a forwarded object, i.e. did
+	// the account making the request also create this?
+	forwarded := !isSender(statusable, requestingAcct)
+
 	// Get the status we have on file for this URI string.
 	status, err := f.state.DB.GetStatusByURI(ctx, statusURIStr)
-	if err != nil {
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		return gtserror.Newf("error fetching status from db: %w", err)
 	}
 
-	// Check that update was by the status author.
-	if status.AccountID != requestingAcct.ID {
-		return gtserror.Newf("update for %s was not requested by author", statusURIStr)
+	if status == nil {
+		// We haven't seen this status before, be
+		// lenient and handle as a CREATE event.
+		return f.createStatusable(ctx,
+			receivingAcct,
+			requestingAcct,
+			statusable,
+			forwarded,
+		)
+	}
+
+	if forwarded {
+		// For forwarded updates, set a nil AS
+		// status to force refresh from remote.
+		statusable = nil
 	}
 
 	// Queue an UPDATE NOTE activity to our fedi API worker,
@@ -134,7 +155,7 @@ func (f *federatingDB) updateStatusable(ctx context.Context, receivingAcct *gtsm
 		APObjectType:     ap.ObjectNote,
 		APActivityType:   ap.ActivityUpdate,
 		GTSModel:         status, // original status
-		APObjectModel:    statusable,
+		APObjectModel:    (ap.Statusable)(statusable),
 		ReceivingAccount: receivingAcct,
 	})
 
diff --git a/internal/federation/federatingdb/util.go b/internal/federation/federatingdb/util.go
index d46451e21..dd7a2240e 100644
--- a/internal/federation/federatingdb/util.go
+++ b/internal/federation/federatingdb/util.go
@@ -20,7 +20,6 @@ package federatingdb
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net/url"
 
@@ -37,6 +36,30 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
 
+func typeNames(objects []ap.TypeOrIRI) []string {
+	names := make([]string, len(objects))
+	for i, object := range objects {
+		if object.IsIRI() {
+			names[i] = "IRI"
+		} else if t := object.GetType(); t != nil {
+			names[i] = t.GetTypeName()
+		} else {
+			names[i] = "nil"
+		}
+	}
+	return names
+}
+
+// isSender returns whether an object with AttributedTo property comes from the given requesting account.
+func isSender(with ap.WithAttributedTo, requester *gtsmodel.Account) bool {
+	for _, uri := range ap.GetAttributedTo(with) {
+		if uri.String() == requester.URI {
+			return true
+		}
+	}
+	return false
+}
+
 func sameActor(actor1 vocab.ActivityStreamsActorProperty, actor2 vocab.ActivityStreamsActorProperty) bool {
 	if actor1 == nil || actor2 == nil {
 		return false
@@ -78,131 +101,31 @@ func (f *federatingDB) NewID(ctx context.Context, t vocab.Type) (idURL *url.URL,
 		l.Debug("entering NewID")
 	}
 
-	switch t.GetTypeName() {
-	case ap.ActivityFollow:
-		// FOLLOW
-		// ID might already be set on a follow we've created, so check it here and return it if it is
-		follow, ok := t.(vocab.ActivityStreamsFollow)
-		if !ok {
-			return nil, errors.New("newid: follow couldn't be parsed into vocab.ActivityStreamsFollow")
-		}
-		idProp := follow.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-		// it's not set so create one based on the actor set on the follow (ie., the followER not the followEE)
-		actorProp := follow.GetActivityStreamsActor()
-		if actorProp != nil {
-			for iter := actorProp.Begin(); iter != actorProp.End(); iter = iter.Next() {
-				// take the IRI of the first actor we can find (there should only be one)
-				if iter.IsIRI() {
-					// if there's an error here, just use the fallback behavior -- we don't need to return an error here
-					if actorAccount, err := f.state.DB.GetAccountByURI(ctx, iter.GetIRI().String()); err == nil {
-						newID, err := id.NewRandomULID()
-						if err != nil {
-							return nil, err
-						}
-						return url.Parse(uris.GenerateURIForFollow(actorAccount.Username, newID))
-					}
+	// Most of our types set an ID already
+	// by this point, return this if found.
+	idProp := t.GetJSONLDId()
+	if idProp != nil && idProp.IsIRI() {
+		return idProp.GetIRI(), nil
+	}
+
+	if t.GetTypeName() == ap.ActivityFollow {
+		follow, _ := t.(vocab.ActivityStreamsFollow)
+
+		// If an actor URI has been set, create a new ID
+		// based on actor (i.e. followER not the followEE).
+		if uri := ap.GetActor(follow); len(uri) == 1 {
+			if actorAccount, err := f.state.DB.GetAccountByURI(ctx, uri[0].String()); err == nil {
+				newID, err := id.NewRandomULID()
+				if err != nil {
+					return nil, err
 				}
-			}
-		}
-	case ap.ObjectNote:
-		// NOTE aka STATUS
-		// ID might already be set on a note we've created, so check it here and return it if it is
-		note, ok := t.(vocab.ActivityStreamsNote)
-		if !ok {
-			return nil, errors.New("newid: note couldn't be parsed into vocab.ActivityStreamsNote")
-		}
-		idProp := note.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-	case ap.ActivityLike:
-		// LIKE aka FAVE
-		// ID might already be set on a fave we've created, so check it here and return it if it is
-		fave, ok := t.(vocab.ActivityStreamsLike)
-		if !ok {
-			return nil, errors.New("newid: fave couldn't be parsed into vocab.ActivityStreamsLike")
-		}
-		idProp := fave.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-	case ap.ActivityCreate:
-		// CREATE
-		// ID might already be set on a Create, so check it here and return it if it is
-		create, ok := t.(vocab.ActivityStreamsCreate)
-		if !ok {
-			return nil, errors.New("newid: create couldn't be parsed into vocab.ActivityStreamsCreate")
-		}
-		idProp := create.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-	case ap.ActivityAnnounce:
-		// ANNOUNCE aka BOOST
-		// ID might already be set on an announce we've created, so check it here and return it if it is
-		announce, ok := t.(vocab.ActivityStreamsAnnounce)
-		if !ok {
-			return nil, errors.New("newid: announce couldn't be parsed into vocab.ActivityStreamsAnnounce")
-		}
-		idProp := announce.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-	case ap.ActivityUpdate:
-		// UPDATE
-		// ID might already be set on an update we've created, so check it here and return it if it is
-		update, ok := t.(vocab.ActivityStreamsUpdate)
-		if !ok {
-			return nil, errors.New("newid: update couldn't be parsed into vocab.ActivityStreamsUpdate")
-		}
-		idProp := update.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-	case ap.ActivityBlock:
-		// BLOCK
-		// ID might already be set on a block we've created, so check it here and return it if it is
-		block, ok := t.(vocab.ActivityStreamsBlock)
-		if !ok {
-			return nil, errors.New("newid: block couldn't be parsed into vocab.ActivityStreamsBlock")
-		}
-		idProp := block.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
-			}
-		}
-	case ap.ActivityUndo:
-		// UNDO
-		// ID might already be set on an undo we've created, so check it here and return it if it is
-		undo, ok := t.(vocab.ActivityStreamsUndo)
-		if !ok {
-			return nil, errors.New("newid: undo couldn't be parsed into vocab.ActivityStreamsUndo")
-		}
-		idProp := undo.GetJSONLDId()
-		if idProp != nil {
-			if idProp.IsIRI() {
-				return idProp.GetIRI(), nil
+				return url.Parse(uris.GenerateURIForFollow(actorAccount.Username, newID))
 			}
 		}
 	}
 
-	// fallback default behavior: just return a random ULID after our protocol and host
+	// Default fallback behaviour:
+	// {proto}://{host}/{randomID}
 	newID, err := id.NewRandomULID()
 	if err != nil {
 		return nil, err