Add support for redactions. Fixes #19

6 files changed, 142 insertions, 1 deletions

diff --git a/go.mod b/go.mod
index 12b9067..c1a6062 100644
--- a/go.mod
+++ b/go.mod
@@ -25,7 +25,7 @@ require (
 	gopkg.in/russross/blackfriday.v2 v2.0.1
 	gopkg.in/toast.v1 v1.0.0-20180812000517-0a84660828b2
 	gopkg.in/yaml.v2 v2.2.2
-	maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616163219-6b4bce05f314
+	maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616174145-055ff7b0fa6a
 	maunium.net/go/mauview v0.0.0-20190606152754-de9e0a754a5d
 	maunium.net/go/tcell v0.0.0-20190606152714-9a88fc07b3ed
 )
diff --git a/go.sum b/go.sum
index 492f270..25767fc 100644
--- a/go.sum
+++ b/go.sum
@@ -98,6 +98,8 @@ maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616140407-62f6f484857e h1:W3NG02SHY
 maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616140407-62f6f484857e/go.mod h1:O+QWJP3H7BZEzIBSrECKpnpRnEKBwaoWVEu/yZwVwxg=
 maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616163219-6b4bce05f314 h1:wGlIqs/L+ErBbAHbkpM4AlFi+9+z9Bsle4xD4Gw+y3k=
 maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616163219-6b4bce05f314/go.mod h1:O+QWJP3H7BZEzIBSrECKpnpRnEKBwaoWVEu/yZwVwxg=
+maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616174145-055ff7b0fa6a h1:DenEIDOOumsU8zDzj5ePQOSaKsxjAxW7UESJ2xo1lxM=
+maunium.net/go/mautrix v0.1.0-alpha.3.0.20190616174145-055ff7b0fa6a/go.mod h1:O+QWJP3H7BZEzIBSrECKpnpRnEKBwaoWVEu/yZwVwxg=
 maunium.net/go/mauview v0.0.0-20190606152754-de9e0a754a5d h1:H4wZ4vMVnOh5QFsb4xZtssgpv3DDEkBRzQ8iyEg2fX0=
 maunium.net/go/mauview v0.0.0-20190606152754-de9e0a754a5d/go.mod h1:GL+akv58wNFzzX4IKLvryKx0F/AcYKHql35DiBzBc/w=
 maunium.net/go/tcell v0.0.0-20190606152714-9a88fc07b3ed h1:sAcUrUZG2LFWBTkTtLKPQvHPHFM5d6huAhr5ZZuxtbQ=
diff --git a/matrix/history.go b/matrix/history.go
index 7275c15..af81ed2 100644
--- a/matrix/history.go
+++ b/matrix/history.go
@@ -21,6 +21,7 @@ import (
 	"compress/gzip"
 	"encoding/binary"
 	"encoding/gob"
+	"errors"
 
 	sync "github.com/sasha-s/go-deadlock"
 	bolt "go.etcd.io/bbolt"
@@ -107,6 +108,37 @@ func (hm *HistoryManager) Get(room *rooms.Room, eventID string) (event *mautrix.
 	return
 }
 
+var EventNotFoundError = errors.New("event not found")
+
+func (hm *HistoryManager) Update(room *rooms.Room, eventID string, update func(event *mautrix.Event) error) error {
+	return hm.db.Update(func (tx *bolt.Tx) error {
+		rid := []byte(room.ID)
+		eventIDs := tx.Bucket(bucketRoomEventIDs).Bucket(rid)
+		if eventIDs == nil {
+			return nil
+		}
+		streamIndex := eventIDs.Get([]byte(eventID))
+		if streamIndex == nil {
+			return nil
+		}
+		stream := tx.Bucket(bucketRoomStreams).Bucket(rid)
+		eventData := stream.Get(streamIndex)
+		if eventData == nil {
+			return EventNotFoundError
+		}
+
+		if event, err := unmarshalEvent(eventData); err != nil {
+			return err
+		} else if err = update(event); err != nil {
+			return err
+		} else if eventData, err = marshalEvent(event); err != nil {
+			return err
+		} else {
+			return stream.Put(streamIndex, eventData)
+		}
+	})
+}
+
 func (hm *HistoryManager) Append(room *rooms.Room, events []*mautrix.Event) error {
 	return hm.store(room, events, true)
 }
diff --git a/matrix/matrix.go b/matrix/matrix.go
index 05736ce..9178ca0 100644
--- a/matrix/matrix.go
+++ b/matrix/matrix.go
@@ -209,6 +209,7 @@ func (c *Container) OnLogin() {
 	// Just pass encrypted events as messages, they'll show up with an encryption unsupported message.
 	c.syncer.OnEventType(mautrix.EventEncrypted, c.HandleMessage)
 	c.syncer.OnEventType(mautrix.EventSticker, c.HandleMessage)
+	c.syncer.OnEventType(mautrix.EventRedaction, c.HandleRedaction)
 	c.syncer.OnEventType(mautrix.StateAliases, c.HandleMessage)
 	c.syncer.OnEventType(mautrix.StateCanonicalAlias, c.HandleMessage)
 	c.syncer.OnEventType(mautrix.StateTopic, c.HandleMessage)
@@ -307,6 +308,41 @@ func (c *Container) SendPreferencesToMatrix() {
 	}
 }
 
+func (c *Container) HandleRedaction(source EventSource, evt *mautrix.Event) {
+	room := c.GetOrCreateRoom(evt.RoomID)
+	var redactedEvt *mautrix.Event
+	err := c.history.Update(room, evt.Redacts, func(redacted *mautrix.Event) error {
+		redacted.Unsigned.RedactedBy = evt.ID
+		redacted.Unsigned.RedactedBecause = evt
+		redactedEvt = redacted
+		return nil
+	})
+	if err != nil {
+		debug.Print("Failed to mark", evt.Redacts, "as redacted:", err)
+	}
+
+	if !room.Loaded() {
+		return
+	}
+
+	mainView := c.ui.MainView()
+
+	roomView := mainView.GetRoom(evt.RoomID)
+	if roomView == nil {
+		debug.Printf("Failed to handle event %v: No room view found.", evt)
+		return
+	}
+
+	// TODO make this less hacky?
+	message := roomView.ParseEvent(redactedEvt)
+	if message != nil {
+		roomView.AddMessage(message)
+		if c.syncer.FirstSyncDone {
+			c.ui.Render()
+		}
+	}
+}
+
 // HandleMessage is the event handler for the m.room.message timeline event.
 func (c *Container) HandleMessage(source EventSource, evt *mautrix.Event) {
 	room := c.GetOrCreateRoom(evt.RoomID)
diff --git a/ui/messages/parser.go b/ui/messages/parser.go
index 29f078c..0b1965e 100644
--- a/ui/messages/parser.go
+++ b/ui/messages/parser.go
@@ -69,6 +69,9 @@ func directParseEvent(matrix ifc.MatrixContainer, room *rooms.Room, evt *mautrix
 	if member != nil {
 		displayname = member.Displayname
 	}
+	if evt.Unsigned.RedactedBecause != nil || evt.Type == mautrix.EventRedaction {
+		return NewRedactedMessage(evt, displayname)
+	}
 	switch evt.Type {
 	case mautrix.EventSticker:
 		evt.Content.MsgType = mautrix.MsgImage
diff --git a/ui/messages/redactedmessage.go b/ui/messages/redactedmessage.go
new file mode 100644
index 0000000..b19ccad
--- /dev/null
+++ b/ui/messages/redactedmessage.go
@@ -0,0 +1,68 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2019 Tulir Asokan
+//
+// 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 <https://www.gnu.org/licenses/>.
+
+package messages
+
+import (
+	ifc "maunium.net/go/gomuks/interface"
+	"maunium.net/go/mautrix"
+	"maunium.net/go/mauview"
+	"maunium.net/go/tcell"
+
+	"maunium.net/go/gomuks/config"
+)
+
+type RedactedMessage struct{}
+
+func NewRedactedMessage(event *mautrix.Event, displayname string) *UIMessage {
+	return newUIMessage(event, displayname, &RedactedMessage{})
+}
+
+func (msg *RedactedMessage) Clone() MessageRenderer {
+	return &RedactedMessage{}
+}
+
+func (msg *RedactedMessage) NotificationContent() string {
+	return ""
+}
+
+func (msg *RedactedMessage) PlainText() string {
+	return "[redacted]"
+}
+
+func (msg *RedactedMessage) String() string {
+	return "&messages.RedactedMessage{}"
+}
+
+func (msg *RedactedMessage) CalculateBuffer(prefs config.UserPreferences, width int, uiMsg *UIMessage) {
+}
+
+func (msg *RedactedMessage) Height() int {
+	return 1
+}
+
+const RedactionChar = '█'
+const RedactionMaxWidth = 40
+var RedactionStyle = tcell.StyleDefault.Foreground(tcell.NewRGBColor(50, 0, 0))
+
+func (msg *RedactedMessage) Draw(screen mauview.Screen) {
+	w, _ := screen.Size()
+	for x := 0; x < w && x < RedactionMaxWidth; x++ {
+		screen.SetContent(x, 0, RedactionChar, nil, RedactionStyle)
+	}
+}
+
+func (msg *RedactedMessage) RegisterMatrix(matrix ifc.MatrixContainer) {}