From 2dfc6a90f3ca9d028ea6fed5efba8b54e8fb36fc Mon Sep 17 00:00:00 2001
From: Mathis Engelbart <mathis.engelbart@gmail.com>
Date: Tue, 19 Mar 2024 22:27:30 +1000
Subject: [PATCH] Improve chat interoperability

---
 examples/chat/client.go | 18 +++++++++++++-----
 examples/chat/room.go   |  2 +-
 examples/chat/server.go | 17 +++++++++++------
 3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/examples/chat/client.go b/examples/chat/client.go
index 635109a..deb84a0 100644
--- a/examples/chat/client.go
+++ b/examples/chat/client.go
@@ -81,7 +81,6 @@ func NewClient(p *moqtransport.Session) (*Client, error) {
 	}
 	go func() {
 		for {
-			var a *moqtransport.Announcement
 			a, err := c.session.ReadAnnouncement(context.Background())
 			if err != nil {
 				panic(err)
@@ -96,7 +95,7 @@ func NewClient(p *moqtransport.Session) (*Client, error) {
 			if err != nil {
 				panic(err)
 			}
-			parts := strings.SplitN(s.Namespace(), "/", 2)
+			parts := strings.SplitN(s.Namespace(), "/", 4)
 			if len(parts) < 2 {
 				s.Reject(moqtransport.SubscribeErrorUnknownTrack, "invalid trackname")
 				continue
@@ -108,9 +107,12 @@ func NewClient(p *moqtransport.Session) (*Client, error) {
 			}
 			if _, ok := c.rooms[id]; !ok {
 				s.Reject(moqtransport.SubscribeErrorUnknownTrack, "invalid subscribe request")
+				log.Printf("got subscribe request for unknown room: %v", id)
 				continue
 			}
 			s.Accept()
+			// TODO: Should add to a list instead of overwriting or at least end
+			// previous subscriptions?
 			c.rooms[id].st = s
 		}
 	}()
@@ -128,11 +130,12 @@ func (c *Client) handleCatalogDeltas(roomID, username string, catalogTrack *moqt
 		if err != nil {
 			return err
 		}
+		log.Printf("got catalog delta: %v", delta)
 		for _, p := range delta.joined {
 			if p == username {
 				continue
 			}
-			t, err := c.session.Subscribe(context.Background(), 0, 0, fmt.Sprintf("moq-chat/%v", roomID), p, username)
+			t, err := c.session.Subscribe(context.Background(), 2, 0, fmt.Sprintf("moq-chat/%v/participant/%v", roomID, p), "", username)
 			if err != nil {
 				return err
 			}
@@ -178,11 +181,12 @@ func (c *Client) joinRoom(roomID, username string) error {
 	if err != nil {
 		return err
 	}
+	log.Printf("got catalog: %v", participants)
 	for p := range participants.participants {
 		if p == username {
 			continue
 		}
-		t, err := c.session.Subscribe(context.Background(), 2, 0, fmt.Sprintf("moq-chat/%v", roomID), p, username)
+		t, err := c.session.Subscribe(context.Background(), 2, 0, fmt.Sprintf("moq-chat/%v/participant/%v", roomID, p), "", username)
 		if err != nil {
 			log.Fatalf("failed to subscribe to participant track: %v", err)
 		}
@@ -231,9 +235,13 @@ func (c *Client) Run() error {
 				fmt.Println("invalid msg command, usage: 'msg <room id> <msg>'")
 				continue
 			}
+			if c.rooms[fields[1]].st == nil {
+				fmt.Println("server not subscribed, dropping message")
+				continue
+			}
 			w, err := c.rooms[fields[1]].st.NewObjectStream(0, 0, 0) // TODO
 			if err != nil {
-				fmt.Printf("failed to send object: %v", err)
+				fmt.Printf("failed to send object: %v\n", err)
 				continue
 			}
 			if _, err = w.Write([]byte(strings.TrimSpace(msg))); err != nil {
diff --git a/examples/chat/room.go b/examples/chat/room.go
index 6e93383..0abc1fa 100644
--- a/examples/chat/room.go
+++ b/examples/chat/room.go
@@ -48,7 +48,7 @@ func (r *room) join(username string, p *moqtransport.Session) error {
 	if _, ok := r.publishers[username]; ok {
 		return errors.New("username already taken")
 	}
-	t, err := p.Subscribe(context.Background(), 0, 0, fmt.Sprintf("moq-chat/%v", r.id), username, "")
+	t, err := p.Subscribe(context.Background(), 0, 0, fmt.Sprintf("moq-chat/%v/participant/%v", r.id, username), "", "")
 	if err != nil {
 		return err
 	}
diff --git a/examples/chat/server.go b/examples/chat/server.go
index 5106fec..96305c1 100644
--- a/examples/chat/server.go
+++ b/examples/chat/server.go
@@ -137,13 +137,13 @@ func (s *Server) handle(p *moqtransport.Session) {
 			if err != nil {
 				panic(err)
 			}
-			uri := strings.SplitN(a.Namespace(), "/", 3)
-			if len(uri) < 3 {
+			uri := strings.SplitN(a.Namespace(), "/", 4)
+			if len(uri) < 4 {
 				a.Reject(0, "invalid announcement")
 				continue
 			}
-			moq_chat, id, username := uri[0], uri[1], uri[2]
-			if moq_chat != "moq-chat" {
+			moq_chat, id, participant, username := uri[0], uri[1], uri[2], uri[3]
+			if moq_chat != "moq-chat" || participant != "participant" {
 				a.Reject(0, "invalid moq-chat namespace")
 				continue
 			}
@@ -170,7 +170,7 @@ func (s *Server) handle(p *moqtransport.Session) {
 				sub.Reject(moqtransport.SubscribeErrorUnknownTrack, "subscribe without prior announcement")
 				continue
 			}
-			parts := strings.SplitN(sub.Namespace(), "/", 2)
+			parts := strings.SplitN(sub.Namespace(), "/", 4)
 			if len(parts) < 2 {
 				sub.Reject(moqtransport.SubscribeErrorUnknownTrack, "invalid trackname")
 				continue
@@ -198,7 +198,12 @@ func (s *Server) handle(p *moqtransport.Session) {
 
 			r.lock.Lock()
 			log.Printf("subscribing user %v to publisher %v", name, sub.Trackname())
-			r.publishers[sub.Trackname()].subscribe(name, sub)
+			if len(parts) < 4 {
+				sub.Reject(0, "invalid subscriptions namespace, expected 'moq-chat/<room-id>/participants/<username>")
+				continue
+			}
+			username := parts[3]
+			r.publishers[username].subscribe(name, sub)
 			r.lock.Unlock()
 		}
 	}()