Follow request improvements (#282)

* tiny doc update

* add rejectfollowrequest to db

* add follow request reject to processor

* add reject handler

* tidy up follow request api

* tidy up federation call

* regenerate swagger docs

* api endpoint tests

* processor test

* add reject federatingdb handler

* start writing reject tests

* test reject follow request

* go fmt

* increase sleep for slow test setups

* more relaxed time.sleep

5 files changed, 221 insertions, 4 deletions

diff --git a/internal/federation/federatingdb/db.go b/internal/federation/federatingdb/db.go
index 039c70168..196d6163c 100644
--- a/internal/federation/federatingdb/db.go
+++ b/internal/federation/federatingdb/db.go
@@ -35,6 +35,7 @@ type DB interface {
 	pub.Database
 	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
 }
 
diff --git a/internal/federation/federatingdb/federatingdb_test.go b/internal/federation/federatingdb/federatingdb_test.go
index 9198266eb..24cbfed98 100644
--- a/internal/federation/federatingdb/federatingdb_test.go
+++ b/internal/federation/federatingdb/federatingdb_test.go
@@ -63,10 +63,10 @@ func (suite *FederatingDBTestSuite) SetupSuite() {
 }
 
 func (suite *FederatingDBTestSuite) SetupTest() {
+	testrig.InitTestLog()
 	suite.config = testrig.NewTestConfig()
 	suite.db = testrig.NewTestDB()
 	suite.tc = testrig.NewTestTypeConverter(suite.db)
-	testrig.InitTestLog()
 	suite.federatingDB = testrig.NewTestFederatingDB(suite.db)
 	testrig.StandardDBSetup(suite.db, suite.testAccounts)
 }
diff --git a/internal/federation/federatingdb/reject.go b/internal/federation/federatingdb/reject.go
new file mode 100644
index 000000000..d05c41654
--- /dev/null
+++ b/internal/federation/federatingdb/reject.go
@@ -0,0 +1,119 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   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"
+	"errors"
+	"fmt"
+
+	"github.com/go-fed/activity/streams/vocab"
+	"github.com/sirupsen/logrus"
+	"github.com/superseriousbusiness/gotosocial/internal/ap"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+)
+
+func (f *federatingDB) Reject(ctx context.Context, reject vocab.ActivityStreamsReject) error {
+	l := logrus.WithFields(
+		logrus.Fields{
+			"func": "Reject",
+		},
+	)
+
+	if logrus.GetLevel() >= logrus.DebugLevel {
+		i, err := marshalItem(reject)
+		if err != nil {
+			return err
+		}
+		l = l.WithField("reject", i)
+		l.Debug("entering Reject")
+	}
+
+	receivingAccount, _, fromFederatorChan := extractFromCtx(ctx)
+	if receivingAccount == nil || fromFederatorChan == nil {
+		// If the receiving account or federator channel wasn't set on the context, that means this request didn't pass
+		// through the API, but came from inside GtS as the result of another activity on this instance. That being so,
+		// we can safely just ignore this activity, since we know we've already processed it elsewhere.
+		return nil
+	}
+
+	rejectObject := reject.GetActivityStreamsObject()
+	if rejectObject == nil {
+		return errors.New("Reject: no object set on vocab.ActivityStreamsReject")
+	}
+
+	for iter := rejectObject.Begin(); iter != rejectObject.End(); iter = iter.Next() {
+		// check if the object is an IRI
+		if iter.IsIRI() {
+			// we have just the URI of whatever is being rejected, so we need to find out what it is
+			rejectedObjectIRI := iter.GetIRI()
+			if util.IsFollowPath(rejectedObjectIRI) {
+				// REJECT FOLLOW
+				gtsFollowRequest := &gtsmodel.FollowRequest{}
+				if err := f.db.GetWhere(ctx, []db.Where{{Key: "uri", Value: rejectedObjectIRI.String()}}, gtsFollowRequest); err != nil {
+					return fmt.Errorf("Reject: couldn't get follow request with id %s from the database: %s", rejectedObjectIRI.String(), err)
+				}
+
+				// make sure the addressee of the original follow is the same as whatever inbox this landed in
+				if gtsFollowRequest.AccountID != receivingAccount.ID {
+					return errors.New("Reject: follow object account and inbox account were not the same")
+				}
+
+				if _, err := f.db.RejectFollowRequest(ctx, gtsFollowRequest.AccountID, gtsFollowRequest.TargetAccountID); err != nil {
+					return err
+				}
+
+				return nil
+			}
+		}
+
+		// check if iter is an AP object / type
+		if iter.GetType() == nil {
+			continue
+		}
+
+		switch iter.GetType().GetTypeName() {
+		// we have the whole object so we can figure out what we're rejecting
+		case ap.ActivityFollow:
+			// REJECT FOLLOW
+			asFollow, ok := iter.GetType().(vocab.ActivityStreamsFollow)
+			if !ok {
+				return errors.New("Reject: couldn't parse follow into vocab.ActivityStreamsFollow")
+			}
+			// convert the follow to something we can understand
+			gtsFollow, err := f.typeConverter.ASFollowToFollow(ctx, asFollow)
+			if err != nil {
+				return fmt.Errorf("Reject: error converting asfollow to gtsfollow: %s", err)
+			}
+			// make sure the addressee of the original follow is the same as whatever inbox this landed in
+			if gtsFollow.AccountID != receivingAccount.ID {
+				return errors.New("Reject: follow object account and inbox account were not the same")
+			}
+			if _, err := f.db.RejectFollowRequest(ctx, gtsFollow.AccountID, gtsFollow.TargetAccountID); err != nil {
+				return err
+			}
+
+			return nil
+		}
+	}
+
+	return nil
+}
diff --git a/internal/federation/federatingdb/reject_test.go b/internal/federation/federatingdb/reject_test.go
new file mode 100644
index 000000000..5e5f12a79
--- /dev/null
+++ b/internal/federation/federatingdb/reject_test.go
@@ -0,0 +1,96 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   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 (
+	"testing"
+	"time"
+
+	"github.com/go-fed/activity/streams"
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/messages"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+	"github.com/superseriousbusiness/gotosocial/testrig"
+)
+
+type RejectTestSuite struct {
+	FederatingDBTestSuite
+}
+
+func (suite *RejectTestSuite) TestRejectFollowRequest() {
+	// local_account_1 sent a follow request to remote_account_2;
+	// remote_account_2 rejects the follow request
+	followingAccount := suite.testAccounts["local_account_1"]
+	followedAccount := suite.testAccounts["remote_account_2"]
+	fromFederatorChan := make(chan messages.FromFederator, 10)
+	ctx := createTestContext(followingAccount, followedAccount, fromFederatorChan)
+
+	// put the follow request in the database
+	fr := &gtsmodel.FollowRequest{
+		ID:              "01FJ1S8DX3STJJ6CEYPMZ1M0R3",
+		CreatedAt:       time.Now(),
+		UpdatedAt:       time.Now(),
+		URI:             util.GenerateURIForFollow(followingAccount.Username, "http", "localhost:8080", "01FJ1S8DX3STJJ6CEYPMZ1M0R3"),
+		AccountID:       followingAccount.ID,
+		TargetAccountID: followedAccount.ID,
+	}
+	err := suite.db.Put(ctx, fr)
+	suite.NoError(err)
+
+	asFollow, err := suite.tc.FollowToAS(ctx, suite.tc.FollowRequestToFollow(ctx, fr), followingAccount, followedAccount)
+	suite.NoError(err)
+
+	rejectingAccountURI := testrig.URLMustParse(followedAccount.URI)
+	requestingAccountURI := testrig.URLMustParse(followingAccount.URI)
+
+	// create a Reject
+	reject := streams.NewActivityStreamsReject()
+
+	// set the rejecting actor on it
+	acceptActorProp := streams.NewActivityStreamsActorProperty()
+	acceptActorProp.AppendIRI(rejectingAccountURI)
+	reject.SetActivityStreamsActor(acceptActorProp)
+
+	// Set the recreated follow as the 'object' property.
+	acceptObject := streams.NewActivityStreamsObjectProperty()
+	acceptObject.AppendActivityStreamsFollow(asFollow)
+	reject.SetActivityStreamsObject(acceptObject)
+
+	// Set the To of the reject as the originator of the follow
+	acceptTo := streams.NewActivityStreamsToProperty()
+	acceptTo.AppendIRI(requestingAccountURI)
+	reject.SetActivityStreamsTo(acceptTo)
+
+	// process the reject in the federating database
+	err = suite.federatingDB.Reject(ctx, reject)
+	suite.NoError(err)
+
+	// there should be nothing in the federator channel since nothing needs to be passed
+	suite.Empty(fromFederatorChan)
+
+	// the follow request should not be in the database anymore -- it's been rejected
+	err = suite.db.GetByID(ctx, fr.ID, &gtsmodel.FollowRequest{})
+	suite.ErrorIs(err, db.ErrNoEntries)
+}
+
+func TestRejectTestSuite(t *testing.T) {
+	suite.Run(t, &RejectTestSuite{})
+}
diff --git a/internal/federation/federatingprotocol.go b/internal/federation/federatingprotocol.go
index ea9084609..504e2dbeb 100644
--- a/internal/federation/federatingprotocol.go
+++ b/internal/federation/federatingprotocol.go
@@ -250,16 +250,17 @@ func (f *federator) FederatingCallbacks(ctx context.Context) (wrapped pub.Federa
 		OnFollow: pub.OnFollowDoNothing,
 	}
 
+	// override some default behaviors and trigger our own side effects
 	other = []interface{}{
-		// override default undo behavior and trigger our own side effects
 		func(ctx context.Context, undo vocab.ActivityStreamsUndo) error {
 			return f.FederatingDB().Undo(ctx, undo)
 		},
-		// override default accept behavior and trigger our own side effects
 		func(ctx context.Context, accept vocab.ActivityStreamsAccept) error {
 			return f.FederatingDB().Accept(ctx, accept)
 		},
-		// override default announce behavior and trigger our own side effects
+		func(ctx context.Context, reject vocab.ActivityStreamsReject) error {
+			return f.FederatingDB().Reject(ctx, reject)
+		},
 		func(ctx context.Context, announce vocab.ActivityStreamsAnnounce) error {
 			return f.FederatingDB().Announce(ctx, announce)
 		},