[feature] Federate reports to remote instance as Flag (if desired) (#1386)

* reports federate out, we did it lxds

* fix optional line start (should be optional slash)

internal/typeutils/converter.go

@@ -188,6 +188,8 @@ type TypeConverter interface {
 	//
 	// Appropriate 'next' and 'prev' fields will be created based on the highest and lowest IDs present in the statuses slice.
 	StatusesToASOutboxPage(ctx context.Context, outboxID string, maxID string, minID string, statuses []*gtsmodel.Status) (vocab.ActivityStreamsOrderedCollectionPage, error)
+	// ReportToASFlag converts a gts model report into an activitystreams FLAG, suitable for federation.
+	ReportToASFlag(ctx context.Context, r *gtsmodel.Report) (vocab.ActivityStreamsFlag, error)
 
 	/*
 		INTERNAL (gts) MODEL TO INTERNAL MODEL

internal/typeutils/internaltoas.go

@@ -1295,3 +1295,53 @@ func (c *converter) OutboxToASCollection(ctx context.Context, outboxID string) (
 
 	return collection, nil
 }
+
+func (c *converter) ReportToASFlag(ctx context.Context, r *gtsmodel.Report) (vocab.ActivityStreamsFlag, error) {
+	flag := streams.NewActivityStreamsFlag()
+
+	flagIDProp := streams.NewJSONLDIdProperty()
+	idURI, err := url.Parse(r.URI)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing url %s: %w", r.URI, err)
+	}
+	flagIDProp.SetIRI(idURI)
+	flag.SetJSONLDId(flagIDProp)
+
+	// for privacy, set the actor as the INSTANCE ACTOR,
+	// not as the actor who created the report
+	instanceAccount, err := c.db.GetInstanceAccount(ctx, "")
+	if err != nil {
+		return nil, fmt.Errorf("error getting instance account: %w", err)
+	}
+	instanceAccountIRI, err := url.Parse(instanceAccount.URI)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing url %s: %w", instanceAccount.URI, err)
+	}
+	flagActorProp := streams.NewActivityStreamsActorProperty()
+	flagActorProp.AppendIRI(instanceAccountIRI)
+	flag.SetActivityStreamsActor(flagActorProp)
+
+	// content should be the comment submitted when the report was created
+	contentProp := streams.NewActivityStreamsContentProperty()
+	contentProp.AppendXMLSchemaString(r.Comment)
+	flag.SetActivityStreamsContent(contentProp)
+
+	// set at least the target account uri as the object of the flag
+	objectProp := streams.NewActivityStreamsObjectProperty()
+	targetAccountURI, err := url.Parse(r.TargetAccount.URI)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing url %s: %w", r.TargetAccount.URI, err)
+	}
+	objectProp.AppendIRI(targetAccountURI)
+	// also set status URIs if they were provided with the report
+	for _, s := range r.Statuses {
+		statusURI, err := url.Parse(s.URI)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing url %s: %w", s.URI, err)
+		}
+		objectProp.AppendIRI(statusURI)
+	}
+	flag.SetActivityStreamsObject(objectProp)
+
+	return flag, nil
+}

internal/typeutils/internaltoas_test.go

@@ -510,6 +510,40 @@ func (suite *InternalToASTestSuite) TestSelfBoostFollowersOnlyToAS() {
 }`, string(bytes))
 }
 
+func (suite *InternalToASTestSuite) TestReportToAS() {
+	ctx := context.Background()
+
+	testReport := suite.testReports["local_account_2_report_remote_account_1"]
+	account := suite.testAccounts["local_account_2"]
+	targetAccount := suite.testAccounts["remote_account_1"]
+	statuses := []*gtsmodel.Status{suite.testStatuses["remote_account_1_status_1"]}
+
+	testReport.Account = account
+	testReport.TargetAccount = targetAccount
+	testReport.Statuses = statuses
+
+	flag, err := suite.typeconverter.ReportToASFlag(ctx, testReport)
+	suite.NoError(err)
+
+	ser, err := streams.Serialize(flag)
+	suite.NoError(err)
+
+	bytes, err := json.MarshalIndent(ser, "", "  ")
+	suite.NoError(err)
+
+	suite.Equal(`{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "actor": "http://localhost:8080/users/localhost:8080",
+  "content": "dark souls sucks, please yeet this nerd",
+  "id": "http://localhost:8080/reports/01GP3AWY4CRDVRNZKW0TEAMB5R",
+  "object": [
+    "http://fossbros-anonymous.io/users/foss_satan",
+    "http://fossbros-anonymous.io/users/foss_satan/statuses/01FVW7JHQFSFK166WWKR8CBA6M"
+  ],
+  "type": "Flag"
+}`, string(bytes))
+}
+
 func TestInternalToASTestSuite(t *testing.T) {
 	suite.Run(t, new(InternalToASTestSuite))
 }