fix(rdp): override Guacamole.Tunnel instance methods, fix sendMessage encoding

frontend/composables/useRdp.ts

@@ -13,23 +13,15 @@ import { useSessionStore } from '~/stores/session.store'
  *   - This tunnel bridges the two: guacamole-common-js sees raw Guacamole
  *     instructions while our gateway sees consistent JSON messages.
  *
- * Protocol:
- *   Browser → Gateway: { type: 'connect', hostId, width, height, ... }
- *   Browser → Gateway: { type: 'guac', instruction: '<raw guac instruction>' }
- *   Gateway → Browser: { type: 'connected', hostId, hostName }
- *   Gateway → Browser: { type: 'guac', instruction: '<raw guac instruction>' }
- *   Gateway → Browser: { type: 'error', message: '...' }
- *   Gateway → Browser: { type: 'disconnected', reason: '...' }
+ * IMPORTANT: Guacamole.Tunnel assigns connect/sendMessage/disconnect as
+ * instance properties in its constructor (not prototype methods). We MUST
+ * reassign them in our constructor AFTER super() to override the no-ops.
  */
 class JsonWsTunnel extends Guacamole.Tunnel {
   private ws: WebSocket | null = null
   private readonly wsUrl: string
   private readonly connectMsg: object
 
-  // Callbacks set by Guacamole.Client after we're constructed
-  oninstruction: ((opcode: string, args: string[]) => void) | null = null
-  onerror: ((status: Guacamole.Status) => void) | null = null
-
   // Expose for external callers (connected event, disconnect action)
   onConnected: ((hostId: number, hostName: string) => void) | null = null
   onDisconnected: ((reason: string) => void) | null = null
@@ -39,15 +31,19 @@ class JsonWsTunnel extends Guacamole.Tunnel {
     super()
     this.wsUrl = wsUrl
     this.connectMsg = connectMsg
+
+    // Override instance methods set by Guacamole.Tunnel constructor
+    this.connect = this._connect.bind(this)
+    this.disconnect = this._disconnect.bind(this)
+    this.sendMessage = this._sendMessage.bind(this)
   }
 
-  connect(_data?: string) {
+  private _connect(_data?: string) {
     console.log('[RDP] Tunnel opening WebSocket:', this.wsUrl)
     this.ws = new WebSocket(this.wsUrl)
 
     this.ws.onopen = () => {
       console.log('[RDP] WebSocket open, sending connect handshake')
-      // Step 1: send our JSON connect handshake
       this.ws!.send(JSON.stringify(this.connectMsg))
     }
 
@@ -56,15 +52,10 @@ class JsonWsTunnel extends Guacamole.Tunnel {
 
       switch (msg.type) {
         case 'connected':
-          // Gateway completed the guacd SELECT→CONNECT handshake.
-          // Notify RdpCanvas so it can finalize the session store entry.
           this.onConnected?.(msg.hostId, msg.hostName)
           break
 
         case 'guac': {
-          // Raw Guacamole instruction from guacd — parse and dispatch to client.
-          // Instructions arrive as: "4.size,4.1024,3.768;" or multiple batched.
-          // We dispatch each complete instruction individually.
           const instruction: string = msg.instruction
           this._dispatchInstructions(instruction)
           break
@@ -93,27 +84,28 @@ class JsonWsTunnel extends Guacamole.Tunnel {
     }
   }
 
-  disconnect() {
+  private _disconnect() {
     if (this.ws && this.ws.readyState === WebSocket.OPEN) {
       this.ws.close()
     }
     this.ws = null
   }
 
-  sendMessage(message: string) {
-    // Guacamole.Client calls this with raw Guacamole instruction strings.
-    // Wrap in JSON envelope and forward to gateway → guacd.
+  private _sendMessage(...elements: any[]) {
+    // Guacamole.Client calls sendMessage(opcode, arg1, arg2, ...) with individual elements.
+    // Encode into Guacamole wire format: "<len>.<value>,<len>.<value>,...;"
     if (this.ws?.readyState === WebSocket.OPEN) {
-      this.ws.send(JSON.stringify({ type: 'guac', instruction: message }))
+      const instruction = elements.map((e: any) => {
+        const s = String(e)
+        return `${s.length}.${s}`
+      }).join(',') + ';'
+      this.ws.send(JSON.stringify({ type: 'guac', instruction }))
     }
   }
 
   /**
    * Parse one or more Guacamole instructions from a raw buffer string
    * and call oninstruction for each.
-   *
-   * Guacamole instruction format: "<len>.<opcode>,<len>.<arg1>,...;"
-   * Multiple instructions may arrive in one data chunk.
    */
   private _dispatchInstructions(raw: string) {
     if (!this.oninstruction) return
@@ -121,14 +113,13 @@ class JsonWsTunnel extends Guacamole.Tunnel {
     let remaining = raw
     while (remaining.length > 0) {
       const semicolonIdx = remaining.indexOf(';')
-      if (semicolonIdx === -1) break // incomplete instruction — guacd shouldn't send partials but be safe
+      if (semicolonIdx === -1) break
 
       const instruction = remaining.substring(0, semicolonIdx)
       remaining = remaining.substring(semicolonIdx + 1)
 
       if (!instruction) continue
 
-      // Parse length-prefixed fields
       const parts: string[] = []
       let pos = 0
       while (pos < instruction.length) {
@@ -138,7 +129,7 @@ class JsonWsTunnel extends Guacamole.Tunnel {
         if (isNaN(len)) break
         const value = instruction.substring(dotIdx + 1, dotIdx + 1 + len)
         parts.push(value)
-        pos = dotIdx + 1 + len + 1 // skip comma separator
+        pos = dotIdx + 1 + len + 1
       }
 
       if (parts.length > 0) {
@@ -181,13 +172,10 @@ export function useRdp() {
 
     const client = new Guacamole.Client(tunnel)
 
-    // Session ID is passed in by the caller (the pending session created in connectHost)
     const sessionId = pendingSessionId
 
-    // Wire tunnel callbacks
     tunnel.onConnected = (_resolvedHostId: number, resolvedHostName: string) => {
       console.log(`[RDP] Connected to ${resolvedHostName}`)
-      // Update the pending session with the resolved host name
       sessions.replaceSession(sessionId, {
         key: sessionId,
         id: sessionId,
@@ -222,13 +210,12 @@ export function useRdp() {
       },
     )
 
-    // Keyboard input — attach to document so key events fire even when
-    // focus is on other elements (toolbar buttons, etc.)
+    // Keyboard input
     const keyboard = new Guacamole.Keyboard(document)
     keyboard.onkeydown = (keysym: number) => client.sendKeyEvent(1, keysym)
     keyboard.onkeyup = (keysym: number) => client.sendKeyEvent(0, keysym)
 
-    // Initiate the WebSocket connection (triggers connect handshake)
+    // Initiate the WebSocket connection
     client.connect()
 
     function disconnect() {