Implement /set command.

README

@@ -109,6 +109,9 @@ to all users:
 
  - `/me text`: sends a chat message starting with the sender's username;
  - `/leave`: equivalent to clicking the *Disconnect* button.
+ - `/set var val`: sets the value of a configuration variable without any
+   error checking.  Without parameters, displays the current configuration.
+ - `/unset var`: removes a configuration variable.
  
 The following commands are only available to users with operator
 privileges:

static/sfu.css

@@ -297,6 +297,11 @@ textarea.form-reply {
     background: #ececec;
 }
 
+.message-system {
+    font-size: 10px;
+    background: #ececec;
+}
+
 .message-row:after, .message-row:before {
     display: table;
     content: " ";

static/sfu.js

@@ -126,6 +126,27 @@ function updateSettings(settings) {
     storeSettings(s);
 }
 
+/**
+ * @param {string} key
+ * @param {any} value
+ */
+function updateSetting(key, value) {
+    let s = {};
+    s[key] = value;
+    updateSettings(s);
+}
+
+/**
+ * @param {string} key
+ */
+function delSetting(key) {
+    let s = getSettings();
+    if(!(key in s))
+        return;
+    delete(s[key]);
+    storeSettings(s)
+}
+
 /**
  * @param {string} id
  */
@@ -1209,8 +1230,10 @@ function addToChatbox(peerId, nick, kind, message){
     let container = document.createElement('div');
     container.classList.add('message');
     row.appendChild(container);
-    if (userpass.username === nick) {
+    if(!peerId)
-      container.classList.add('message-sender');
+        container.classList.add('message-system');
+    else if(userpass.username === nick) {
+        container.classList.add('message-sender');
     }
     if(kind !== 'me') {
         let p = formatLines(message.split('\n'));
@@ -1333,6 +1356,33 @@ function handleInput() {
                 }
                 serverConnection.groupAction('clearchat');
                 return;
+            case '/set':
+                if(!rest) {
+                    let settings = getSettings();
+                    let s = "";
+                    for(let key in settings)
+                        s = s + `${key}: ${JSON.stringify(settings[key])}\n`
+                    addToChatbox(null, null, null, s);
+                    return;
+                }
+                let parsed = parseCommand(rest);
+                let value;
+                if(parsed[1]) {
+                    try {
+                        value = JSON.parse(parsed[1])
+                    } catch(e) {
+                        displayError(e);
+                        return;
+                    }
+                } else {
+                    value = true;
+                }
+                updateSetting(parsed[0], value);
+                reflectSettings();
+                return;
+            case '/unset':
+                delSetting(rest.trim());
+                return;
             case '/lock':
             case '/unlock':
                 if(!serverConnection.permissions.op) {