Tauri for Local AI Engineering: Rust Core, llama.cpp & Privacy

use tauri::ipc::Channel;
use std::thread;
use std::time::Duration;

#[derive(Clone, serde::Serialize)]
struct TokenStreamPayload {
  token: String,
  done: bool,
}

// Tauri IPC async command handler for local AI token generation
#[tauri::command]
async fn generate_local_tokens(prompt: String, on_event: Channel<TokenStreamPayload>) -> Result<(), String> {
  // Spawn background Rust thread to run llama.cpp tensor generation without blocking UI thread
  thread::spawn(move || {
      let sample_response = vec!["Tauri ", "executes ", "local ", "AI ", "models ", "100% ", "offline ", "with ", "zero ", "cloud ", "latency."];
      
      for token in sample_response {
          thread::sleep(Duration::from_millis(35)); // Simulate local GPU token decode speed
          let _ = on_event.send(TokenStreamPayload {
              token: token.to_string(),
              done: false,
          });
      }
      
      // Emit completion payload channel signal
      let _ = on_event.send(TokenStreamPayload {
          token: String::new(),
          done: true,
      });
  });

  Ok(())
}

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
  tauri::Builder::default()
      .invoke_handler(tauri::generate_handler![generate_local_tokens])
      .run(tauri::generate_context!())
      .expect("error while running tauri application");
}