[bugfix] Normalize status content (don't parse status content as IRI) (#1665)

* start fannying about

* finish up Normalize

* tidy up

* pin to tag

* move errors about just a little bit

internal/ap/normalize.go

@@ -0,0 +1,116 @@
+// 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 ap
+
+import (
+	"github.com/superseriousbusiness/activity/pub"
+	"github.com/superseriousbusiness/activity/streams"
+)
+
+// NormalizeActivityObject normalizes the 'object'.'content' field of the given Activity.
+//
+// The rawActivity map should the freshly deserialized json representation of the Activity.
+//
+// This function is a noop if the type passed in is anything except a Create with a Statusable as its Object.
+func NormalizeActivityObject(activity pub.Activity, rawActivity map[string]interface{}) {
+	if activity.GetTypeName() != ActivityCreate {
+		// Only interested in Create right now.
+		return
+	}
+
+	withObject, ok := activity.(WithObject)
+	if !ok {
+		// Create was not a WithObject.
+		return
+	}
+
+	createObject := withObject.GetActivityStreamsObject()
+	if createObject == nil {
+		// No object set.
+		return
+	}
+
+	if createObject.Len() != 1 {
+		// Not interested in Object arrays.
+		return
+	}
+
+	// We now know length is 1 so get the first
+	// item from the iter.  We need this to be
+	// a Statusable if we're to continue.
+	i := createObject.At(0)
+	if i == nil {
+		// This is awkward.
+		return
+	}
+
+	t := i.GetType()
+	if t == nil {
+		// This is also awkward.
+		return
+	}
+
+	statusable, ok := t.(Statusable)
+	if !ok {
+		// Object is not Statusable;
+		// we're not interested.
+		return
+	}
+
+	object, ok := rawActivity["object"]
+	if !ok {
+		// No object in raw map.
+		return
+	}
+
+	rawStatusable, ok := object.(map[string]interface{})
+	if !ok {
+		// Object wasn't a json object.
+		return
+	}
+
+	// Pass in the statusable and its raw JSON representation.
+	NormalizeStatusableContent(statusable, rawStatusable)
+}
+
+// NormalizeStatusableContent replaces the Content of the given statusable
+// with the raw 'content' value from the given json object map.
+//
+// noop if there was no content in the json object map or the content was
+// not a plain string.
+func NormalizeStatusableContent(statusable Statusable, rawStatusable map[string]interface{}) {
+	content, ok := rawStatusable["content"]
+	if !ok {
+		// No content in rawStatusable.
+		// TODO: In future we might also
+		// look for "contentMap" property.
+		return
+	}
+
+	rawContent, ok := content.(string)
+	if !ok {
+		// Not interested in content arrays.
+		return
+	}
+
+	// Set normalized content property from the raw string; this
+	// will replace any existing content property on the statusable.
+	contentProp := streams.NewActivityStreamsContentProperty()
+	contentProp.AppendXMLSchemaString(rawContent)
+	statusable.SetActivityStreamsContent(contentProp)
+}