From 27a2e45500627f7f97fff582265143e34026c292 Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Wed, 2 Dec 2020 19:47:32 +0100
Subject: [PATCH] Implement /subgroups.

---
 group/group.go       | 24 ++++++++++++++++++++++++
 rtpconn/webclient.go | 21 +++++++++++++++++++++
 static/sfu.js        |  8 ++++++++
 3 files changed, 53 insertions(+)

diff --git a/group/group.go b/group/group.go
index e766aab..f3b5f57 100644
--- a/group/group.go
+++ b/group/group.go
@@ -259,6 +259,30 @@ func GetNames() []string {
 	return names
 }
 
+type SubGroup struct {
+	Name    string
+	Clients int
+}
+
+func GetSubGroups(parent string) []SubGroup {
+	prefix := parent + "/"
+	subgroups := make([]SubGroup, 0)
+
+	Range(func(g *Group) bool {
+		if strings.HasPrefix(g.name, prefix) {
+			g.mu.Lock()
+			count := len(g.clients)
+			g.mu.Unlock()
+			if count > 0 {
+				subgroups = append(subgroups,
+					SubGroup{g.name, count})
+			}
+		}
+		return true
+	})
+	return subgroups
+}
+
 func Get(name string) *Group {
 	groups.mu.Lock()
 	defer groups.mu.Unlock()
diff --git a/rtpconn/webclient.go b/rtpconn/webclient.go
index 30c83ca..389e27f 100644
--- a/rtpconn/webclient.go
+++ b/rtpconn/webclient.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"sync"
 	"time"
+	"fmt"
 
 	"github.com/gorilla/websocket"
 	"github.com/pion/webrtc/v3"
@@ -1218,6 +1219,26 @@ func handleClientMessage(c *webClient, m clientMessage) error {
 					group.DelClient(disk)
 				}
 			}
+		case "subgroups":
+			if !c.permissions.Op {
+				return c.error(group.UserError("not authorised"))
+			}
+			s := ""
+			for _, sg := range group.GetSubGroups(g.Name()) {
+				plural := ""
+				if sg.Clients > 1 {
+					plural = "s"
+				}
+				s = s + fmt.Sprintf("%v (%v client%v)",
+					sg.Name, sg.Clients, plural)
+			}
+			c.write(clientMessage{
+				Type:  "chat",
+				Dest:  c.id,
+				Username: "Server",
+				Time:  group.ToJSTime(time.Now()),
+				Value: &s,
+			})
 		default:
 			return group.ProtocolError("unknown group action")
 		}
diff --git a/static/sfu.js b/static/sfu.js
index c48bc41..7872ef0 100644
--- a/static/sfu.js
+++ b/static/sfu.js
@@ -1759,6 +1759,14 @@ commands.unrecord = {
     }
 };
 
+commands.subgroups = {
+    predicate: operatorPredicate,
+    description: 'list subgroups',
+    f: (c, r) => {
+        serverConnection.groupAction(getUsername(), 'subgroups');
+    }
+};
+
 /**
  * parseCommand splits a string into two space-separated parts.  The first
  * part may be quoted and may include backslash escapes.