[feature] Process incoming `Move` activity (#2724)

* [feature] Process incoming account Move activity

* fix targetAcct typo

* put move origin account on fMsg

* shift more move functionality back to the worker fn

* simplify error logic

6 files changed, 408 insertions, 0 deletions

diff --git a/internal/federation/federatingdb/accept.go b/internal/federation/federatingdb/accept.go
index e1d754f2e..7ec9346e0 100644
--- a/internal/federation/federatingdb/accept.go
+++ b/internal/federation/federatingdb/accept.go
@@ -49,6 +49,12 @@ func (f *federatingDB) Accept(ctx context.Context, accept vocab.ActivityStreamsA
 	requestingAcct := activityContext.requestingAcct
 	receivingAcct := activityContext.receivingAcct
 
+	if requestingAcct.IsMoving() {
+		// A Moving account
+		// can't do this.
+		return nil
+	}
+
 	// Iterate all provided objects in the activity.
 	for _, object := range ap.ExtractObjects(accept) {
 
diff --git a/internal/federation/federatingdb/announce.go b/internal/federation/federatingdb/announce.go
index 2ce6d1c59..e13e212da 100644
--- a/internal/federation/federatingdb/announce.go
+++ b/internal/federation/federatingdb/announce.go
@@ -49,6 +49,12 @@ func (f *federatingDB) Announce(ctx context.Context, announce vocab.ActivityStre
 	requestingAcct := activityContext.requestingAcct
 	receivingAcct := activityContext.receivingAcct
 
+	if requestingAcct.IsMoving() {
+		// A Moving account
+		// can't do this.
+		return nil
+	}
+
 	// Ensure requestingAccount is among
 	// the Actors doing the Announce.
 	//
diff --git a/internal/federation/federatingdb/create.go b/internal/federation/federatingdb/create.go
index cfb0f319b..cacaf07cf 100644
--- a/internal/federation/federatingdb/create.go
+++ b/internal/federation/federatingdb/create.go
@@ -68,6 +68,12 @@ func (f *federatingDB) Create(ctx context.Context, asType vocab.Type) error {
 	requestingAcct := activityContext.requestingAcct
 	receivingAcct := activityContext.receivingAcct
 
+	if requestingAcct.IsMoving() {
+		// A Moving account
+		// can't do this.
+		return nil
+	}
+
 	switch asType.GetTypeName() {
 	case ap.ActivityBlock:
 		// BLOCK SOMETHING
diff --git a/internal/federation/federatingdb/db.go b/internal/federation/federatingdb/db.go
index 2174a8003..12bd5a376 100644
--- a/internal/federation/federatingdb/db.go
+++ b/internal/federation/federatingdb/db.go
@@ -31,11 +31,18 @@ import (
 // DB wraps the pub.Database interface with
 // a couple of custom functions for GoToSocial.
 type DB interface {
+	// Default functionality.
 	pub.Database
+
+	/*
+		Overridden functionality for calling from federatingProtocol.
+	*/
+
 	Undo(ctx context.Context, undo vocab.ActivityStreamsUndo) error
 	Accept(ctx context.Context, accept vocab.ActivityStreamsAccept) error
 	Reject(ctx context.Context, reject vocab.ActivityStreamsReject) error
 	Announce(ctx context.Context, announce vocab.ActivityStreamsAnnounce) error
+	Move(ctx context.Context, move vocab.ActivityStreamsMove) error
 }
 
 // FederatingDB uses the given state interface
diff --git a/internal/federation/federatingdb/move.go b/internal/federation/federatingdb/move.go
new file mode 100644
index 000000000..2e8049e08
--- /dev/null
+++ b/internal/federation/federatingdb/move.go
@@ -0,0 +1,182 @@
+// 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 gtsmodel contains types used *internally* by GoToSocial and added/removed/selected from the database.
+// These types should never be serialized and/or sent out via public APIs, as they contain sensitive information.
+// The annotation used on these structs is for handling them via the bun-db ORM.
+// See here for more info on bun model annotations: https://bun.uptrace.dev/guide/models.html
+
+package federatingdb
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"codeberg.org/gruf/go-logger/v2/level"
+	"github.com/superseriousbusiness/activity/streams/vocab"
+	"github.com/superseriousbusiness/gotosocial/internal/ap"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/messages"
+)
+
+func (f *federatingDB) Move(ctx context.Context, move vocab.ActivityStreamsMove) error {
+	if log.Level() >= level.DEBUG {
+		i, err := marshalItem(move)
+		if err != nil {
+			return err
+		}
+		l := log.WithContext(ctx).
+			WithField("move", i)
+		l.Debug("entering Move")
+	}
+
+	activityContext := getActivityContext(ctx)
+	if activityContext.internal {
+		// Already processed.
+		return nil
+	}
+
+	requestingAcct := activityContext.requestingAcct
+	receivingAcct := activityContext.receivingAcct
+
+	if requestingAcct.IsLocal() {
+		// We should not be processing
+		// a Move sent from our own
+		// instance in the federatingDB.
+		return nil
+	}
+
+	// Basic Move requirements we can
+	// check at this point already:
+	//
+	//   - Move must have ID/URI set.
+	//   - Move `object` and `actor` must
+	//     be set, and must be the same
+	//     as requesting account.
+	//   - Move `target` must be set, and
+	//     must *not* be the same as
+	//     requesting account.
+	//   - Move `target` and `object` must
+	//     not have been involved in a
+	//     successful Move within the
+	//     last 7 days.
+	//
+	// If the Move looks OK at this point,
+	// additional requirements and checks
+	// will be processed in FromFediAPI.
+
+	// Ensure ID/URI set.
+	moveURI := ap.GetJSONLDId(move)
+	if moveURI == nil {
+		err := errors.New("Move ID/URI was nil")
+		return gtserror.SetMalformed(err)
+	}
+	moveURIStr := moveURI.String()
+
+	// Check `object` property.
+	objects := ap.GetObjectIRIs(move)
+	if l := len(objects); l != 1 {
+		err := fmt.Errorf("Move requires exactly 1 object, had %d", l)
+		return gtserror.SetMalformed(err)
+	}
+	object := objects[0]
+	objectStr := object.String()
+
+	if objectStr != requestingAcct.URI {
+		err := fmt.Errorf(
+			"Move was signed by %s but object was %s",
+			requestingAcct.URI, objectStr,
+		)
+		return gtserror.SetMalformed(err)
+	}
+
+	// Check `actor` property.
+	actors := ap.GetActorIRIs(move)
+	if l := len(actors); l != 1 {
+		err := fmt.Errorf("Move requires exactly 1 actor, had %d", l)
+		return gtserror.SetMalformed(err)
+	}
+	actor := actors[0]
+	actorStr := actor.String()
+
+	if actorStr != requestingAcct.URI {
+		err := fmt.Errorf(
+			"Move was signed by %s but actor was %s",
+			requestingAcct.URI, actorStr,
+		)
+		return gtserror.SetMalformed(err)
+	}
+
+	// Check `target` property.
+	targets := ap.GetTargetIRIs(move)
+	if l := len(targets); l != 1 {
+		err := fmt.Errorf("Move requires exactly 1 target, had %d", l)
+		return gtserror.SetMalformed(err)
+	}
+	target := targets[0]
+	targetStr := target.String()
+
+	if targetStr == requestingAcct.URI {
+		err := fmt.Errorf(
+			"Move target and origin were the same (%s)",
+			targetStr,
+		)
+		return gtserror.SetMalformed(err)
+	}
+
+	// If movedToURI is set on requestingAcct,
+	// make sure it points to the intended target.
+	//
+	// If it's not set, that's fine, we don't
+	// need it right now. We know by now that the
+	// Move was really sent to us by requestingAcct.
+	movedToURI := receivingAcct.MovedToURI
+	if movedToURI != "" &&
+		movedToURI != targetStr {
+		err := fmt.Errorf(
+			"origin account movedTo is set to %s, which differs from Move target; will not process Move",
+			movedToURI,
+		)
+		return gtserror.SetMalformed(err)
+	}
+
+	// Create a stub *gtsmodel.Move with relevant
+	// values. This will be updated / stored by the
+	// fedi api worker as necessary.
+	stubMove := &gtsmodel.Move{
+		OriginURI: objectStr,
+		Origin:    object,
+		TargetURI: targetStr,
+		Target:    target,
+		URI:       moveURIStr,
+	}
+
+	// We had a Move already or stored a new Move.
+	// Pass back to a worker for async processing.
+	f.state.Workers.EnqueueFediAPI(ctx, messages.FromFediAPI{
+		APObjectType:      ap.ObjectProfile,
+		APActivityType:    ap.ActivityMove,
+		GTSModel:          stubMove,
+		RequestingAccount: requestingAcct,
+		ReceivingAccount:  receivingAcct,
+	})
+
+	return nil
+}
diff --git a/internal/federation/federatingdb/move_test.go b/internal/federation/federatingdb/move_test.go
new file mode 100644
index 000000000..006dcf0dc
--- /dev/null
+++ b/internal/federation/federatingdb/move_test.go
@@ -0,0 +1,201 @@
+// 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_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/activity/streams"
+	"github.com/superseriousbusiness/activity/streams/vocab"
+	"github.com/superseriousbusiness/gotosocial/internal/ap"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/messages"
+)
+
+type MoveTestSuite struct {
+	FederatingDBTestSuite
+}
+
+func (suite *MoveTestSuite) move(
+	receivingAcct *gtsmodel.Account,
+	requestingAcct *gtsmodel.Account,
+	moveStr string,
+) error {
+	ctx := createTestContext(receivingAcct, requestingAcct)
+
+	rawMove := make(map[string]interface{})
+	if err := json.Unmarshal([]byte(moveStr), &rawMove); err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	t, err := streams.ToType(ctx, rawMove)
+	if err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	move, ok := t.(vocab.ActivityStreamsMove)
+	if !ok {
+		suite.FailNow("", "couldn't cast %T to Move", t)
+	}
+
+	return suite.federatingDB.Move(ctx, move)
+}
+
+func (suite *MoveTestSuite) TestMove() {
+	var (
+		receivingAcct  = suite.testAccounts["local_account_1"]
+		requestingAcct = suite.testAccounts["remote_account_1"]
+		moveStr1       = `{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://fossbros-anonymous.io/users/foss_satan/moves/01HR9FDFCAGM7JYPMWNTFRDQE9",
+  "actor": "http://fossbros-anonymous.io/users/foss_satan",
+  "type": "Move",
+  "object": "http://fossbros-anonymous.io/users/foss_satan",
+  "target": "https://turnip.farm/users/turniplover6969",
+  "to": "http://fossbros-anonymous.io/users/foss_satan/followers"
+}`
+	)
+
+	// Trigger the move.
+	suite.move(receivingAcct, requestingAcct, moveStr1)
+
+	// Should be a message heading to the processor.
+	var msg messages.FromFediAPI
+	select {
+	case msg = <-suite.fromFederator:
+		// Fine.
+	case <-time.After(5 * time.Second):
+		suite.FailNow("", "timeout waiting for suite.fromFederator")
+	}
+	suite.Equal(ap.ObjectProfile, msg.APObjectType)
+	suite.Equal(ap.ActivityMove, msg.APActivityType)
+
+	// Stub Move should be on the message.
+	move, ok := msg.GTSModel.(*gtsmodel.Move)
+	if !ok {
+		suite.FailNow("", "could not cast %T to *gtsmodel.Move", msg.GTSModel)
+	}
+	suite.Equal("http://fossbros-anonymous.io/users/foss_satan", move.OriginURI)
+	suite.Equal("https://turnip.farm/users/turniplover6969", move.TargetURI)
+
+	// Trigger the same move again.
+	suite.move(receivingAcct, requestingAcct, moveStr1)
+
+	// Should be a message heading to the processor
+	// since this is just a straight up retry.
+	select {
+	case msg = <-suite.fromFederator:
+		// Fine.
+	case <-time.After(5 * time.Second):
+		suite.FailNow("", "timeout waiting for suite.fromFederator")
+	}
+	suite.Equal(ap.ObjectProfile, msg.APObjectType)
+	suite.Equal(ap.ActivityMove, msg.APActivityType)
+
+	// Same as the first Move, but with a different ID.
+	moveStr2 := `{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://fossbros-anonymous.io/users/foss_satan/moves/01HR9XWDD25CKXHW82MYD1GDAR",
+  "actor": "http://fossbros-anonymous.io/users/foss_satan",
+  "type": "Move",
+  "object": "http://fossbros-anonymous.io/users/foss_satan",
+  "target": "https://turnip.farm/users/turniplover6969",
+  "to": "http://fossbros-anonymous.io/users/foss_satan/followers"
+}`
+
+	// Trigger the move.
+	suite.move(receivingAcct, requestingAcct, moveStr2)
+
+	// Should be a message heading to the processor
+	// since this is just a retry with a different ID.
+	select {
+	case msg = <-suite.fromFederator:
+		// Fine.
+	case <-time.After(5 * time.Second):
+		suite.FailNow("", "timeout waiting for suite.fromFederator")
+	}
+	suite.Equal(ap.ObjectProfile, msg.APObjectType)
+	suite.Equal(ap.ActivityMove, msg.APActivityType)
+}
+
+func (suite *MoveTestSuite) TestBadMoves() {
+	var (
+		receivingAcct  = suite.testAccounts["local_account_1"]
+		requestingAcct = suite.testAccounts["remote_account_1"]
+	)
+
+	type testStruct struct {
+		moveStr string
+		err     string
+	}
+
+	for _, t := range []testStruct{
+		{
+			// Move signed by someone else.
+			moveStr: `{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://fossbros-anonymous.io/users/foss_satan/moves/01HR9FDFCAGM7JYPMWNTFRDQE9",
+  "actor": "http://fossbros-anonymous.io/users/someone_else",
+  "type": "Move",
+  "object": "http://fossbros-anonymous.io/users/foss_satan",
+  "target": "https://turnip.farm/users/turniplover6969",
+  "to": "http://fossbros-anonymous.io/users/foss_satan/followers"
+}`,
+			err: "Move was signed by http://fossbros-anonymous.io/users/foss_satan but actor was http://fossbros-anonymous.io/users/someone_else",
+		},
+		{
+			// Actor and object not the same.
+			moveStr: `{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://fossbros-anonymous.io/users/foss_satan/moves/01HR9FDFCAGM7JYPMWNTFRDQE9",
+  "actor": "http://fossbros-anonymous.io/users/foss_satan",
+  "type": "Move",
+  "object": "http://fossbros-anonymous.io/users/someone_else",
+  "target": "https://turnip.farm/users/turniplover6969",
+  "to": "http://fossbros-anonymous.io/users/foss_satan/followers"
+}`,
+			err: "Move was signed by http://fossbros-anonymous.io/users/foss_satan but object was http://fossbros-anonymous.io/users/someone_else",
+		},
+		{
+			// Object and target the same.
+			moveStr: `{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "id": "http://fossbros-anonymous.io/users/foss_satan/moves/01HR9FDFCAGM7JYPMWNTFRDQE9",
+  "actor": "http://fossbros-anonymous.io/users/foss_satan",
+  "type": "Move",
+  "object": "http://fossbros-anonymous.io/users/foss_satan",
+  "target": "http://fossbros-anonymous.io/users/foss_satan",
+  "to": "http://fossbros-anonymous.io/users/foss_satan/followers"
+}`,
+			err: "Move target and origin were the same (http://fossbros-anonymous.io/users/foss_satan)",
+		},
+	} {
+		// Trigger the move.
+		err := suite.move(receivingAcct, requestingAcct, t.moveStr)
+		if t.err != "" {
+			suite.EqualError(err, t.err)
+		}
+	}
+}
+
+func TestMoveTestSuite(t *testing.T) {
+	suite.Run(t, &MoveTestSuite{})
+}