TS3-vibed/Documentation/Mile_Stones/Milestone_2.md

Milestone 2: Local Audio & GUI (The Ears)

Goal: Enable the client to process high-quality audio locally and display the interface.

1. UI Layout (client_node/ui)

• Dependencies: Add egui, eframe.
• AI Context Trap (Eframe + Tokio): Do NOT use #[tokio::main] on the client. eframe demands the main thread. Manually build a tokio::runtime::Runtime, spawn the background network actors, and pass MPSC channels into the AppState before calling eframe::run_native().
• Architecture: Create struct AppState. Implement eframe::App trait for it.
• Layout: Build the basic classic TeamSpeak UI. Left panel (tree view of hardcoded channels), right panel (text chat log).

2. Audio Capture (client_node/audio/capture.rs)

• Dependencies: Add cpal, ringbuf.
• Device Setup: Use cpal::default_host().default_input_device(). Build a stream config specifically requesting 48,000 Hz and 1 channel (Mono).
• Headless Abstraction: Ensure the cpal instantiation is hidden behind a trait so the CI test suite can inject deterministic "sine wave" f32 vectors instead of requiring a physical microphone.
• The Producer: Create a ringbuf::HeapRb<f32> (e.g., 4096 capacity). Split it into (producer, consumer).
• Hardware Callback: Inside the cpal data callback, write the raw f32 samples directly into the producer. Strictly no_std-like rules here (no allocations, no locks).

3. DSP Chain & VAD (client_node/audio/dsp.rs)

• Dependencies: Add webrtc-audio-processing.
• Thread Spawning: Spawn a standard std::thread (not tokio) to act as the Audio Consumer.
• Processing Loop: Pull chunks of exactly 960 samples (20ms) from the consumer ringbuffer.
• Filters: Pass the 960 samples through webrtc's EchoCancellation and NoiseSuppression methods.
• Voice Activity Detection (VAD): Implement webrtc VAD or an amplitude threshold calculator. If the chunk is "silence", drop it to save bandwidth.

4. Global Hotkeys / Push-To-Talk (PTT)

• Dependencies: Add global-hotkey (or rdev).
• Event Loop: Spawn a thread to listen for a specific keycode (e.g., Mouse4 or V).
• Integration: Update an Arc<AtomicBool> is_transmitting flag. The DSP thread reads this flag; if false, it dumps the audio chunks.

5. Local Loopback & UI Bridge

• Loopback Thread: For testing, route the post-DSP 960-sample chunks directly into a cpal output stream (Speaker) to physically hear the microphone quality and VAD gating.
• UI State Bridge: Use tokio::sync::mpsc or simple Arc<AtomicBool> to signal the UI thread when VAD triggers, so egui can draw the green "Active Speaker" dot next to the user's name.
• Audio Dumper UI: Add a checkbox in the egui settings panel. When checked, write the 960-sample chunks to raw_mic.wav and post_dsp.wav using the hound crate for local inspection.