Add option to enforce strict compatibility

Some plugins check for token length. Since PushBits uses longer tokens by default for better security, these plugins are
incompatible. With this patch, users can decide if they want an application to have a short token, so that said plugins
can talk to PushBits again.

internal/dispatcher/application.go

@@ -9,23 +9,25 @@ import (
 	"github.com/matrix-org/gomatrix"
 )
 
+func buildRoomTopic(id uint) string {
+	return fmt.Sprintf("Application %d", id)
+}
+
 // RegisterApplication creates a channel for an application.
 func (d *Dispatcher) RegisterApplication(id uint, name, token, user string) (string, error) {
 	log.Printf("Registering application %s, notifications will be relayed to user %s.\n", name, user)
 
-	topic := fmt.Sprintf("Application %d, Token %s", id, token)
-
 	response, err := d.client.CreateRoom(&gomatrix.ReqCreateRoom{
 		Invite:     []string{user},
 		IsDirect:   true,
 		Name:       name,
 		Preset:     "private_chat",
-		Topic:      topic,
+		Topic:      buildRoomTopic(id),
 		Visibility: "private",
 	})
 
 	if err != nil {
-		log.Fatal(err)
+		log.Print(err)
 		return "", err
 	}
 
@@ -44,17 +46,49 @@ func (d *Dispatcher) DeregisterApplication(a *model.Application, u *model.User)
 	}
 
 	if _, err := d.client.KickUser(a.MatrixID, kickUser); err != nil {
-		log.Fatal(err)
+		log.Print(err)
 		return err
 	}
 
 	if _, err := d.client.LeaveRoom(a.MatrixID); err != nil {
-		log.Fatal(err)
+		log.Print(err)
 		return err
 	}
 
 	if _, err := d.client.ForgetRoom(a.MatrixID); err != nil {
-		log.Fatal(err)
+		log.Print(err)
+		return err
+	}
+
+	return nil
+}
+
+func (d *Dispatcher) sendRoomEvent(roomID, eventType string, content interface{}) error {
+	if _, err := d.client.SendStateEvent(roomID, eventType, "", content); err != nil {
+		log.Print(err)
+		return err
+	}
+
+	return nil
+}
+
+// UpdateApplication updates a channel for an application.
+func (d *Dispatcher) UpdateApplication(a *model.Application, u *model.User) error {
+	log.Printf("Updating application %s (ID %d) with Matrix ID %s.\n", a.Name, a.ID, a.MatrixID)
+
+	content := map[string]interface{}{
+		"name": a.Name,
+	}
+
+	if err := d.sendRoomEvent(a.MatrixID, "m.room.name", content); err != nil {
+		return err
+	}
+
+	content = map[string]interface{}{
+		"topic": buildRoomTopic(a.ID),
+	}
+
+	if err := d.sendRoomEvent(a.MatrixID, "m.room.topic", content); err != nil {
 		return err
 	}