use alsa by default on linux (#190)

* use alsa by default on linux

* only import trait when needed

src-tauri/src/audio_feedback.rs

@@ -67,7 +67,7 @@ fn play_audio_file(
             OutputStreamBuilder::from_default_device()?
         } else {
             // Try to find the device by name
-            let host = cpal::default_host();
+            let host = crate::audio_toolkit::get_cpal_host();
             let devices = host.output_devices()?;
 
             let mut found_device = None;

src-tauri/src/audio_toolkit/audio/device.rs

@@ -8,7 +8,7 @@ pub struct CpalDeviceInfo {
 }
 
 pub fn list_input_devices() -> Result<Vec<CpalDeviceInfo>, Box<dyn std::error::Error>> {
-    let host = cpal::default_host();
+    let host = crate::audio_toolkit::get_cpal_host();
     let default_name = host.default_input_device().and_then(|d| d.name().ok());
 
     let mut out = Vec::<CpalDeviceInfo>::new();
@@ -30,7 +30,7 @@ pub fn list_input_devices() -> Result<Vec<CpalDeviceInfo>, Box<dyn std::error::E
 }
 
 pub fn list_output_devices() -> Result<Vec<CpalDeviceInfo>, Box<dyn std::error::Error>> {
-    let host = cpal::default_host();
+    let host = crate::audio_toolkit::get_cpal_host();
     let default_name = host.default_output_device().and_then(|d| d.name().ok());
 
     let mut out = Vec::<CpalDeviceInfo>::new();

src-tauri/src/audio_toolkit/audio/recorder.rs

@@ -62,7 +62,7 @@ impl AudioRecorder {
         let (sample_tx, sample_rx) = mpsc::channel::<Vec<f32>>();
         let (cmd_tx, cmd_rx) = mpsc::channel::<Cmd>();
 
-        let host = cpal::default_host();
+        let host = crate::audio_toolkit::get_cpal_host();
         let device = match device {
             Some(dev) => dev,
             None => host

src-tauri/src/audio_toolkit/mod.rs

@@ -1,10 +1,12 @@
 pub mod audio;
 pub mod constants;
 pub mod text;
+pub mod utils;
 pub mod vad;
 
 pub use audio::{
     list_input_devices, list_output_devices, save_wav_file, AudioRecorder, CpalDeviceInfo,
 };
 pub use text::apply_custom_words;
+pub use utils::get_cpal_host;
 pub use vad::{SileroVad, VoiceActivityDetector};

src-tauri/src/audio_toolkit/utils.rs

@@ -0,0 +1,13 @@
+/// Returns the appropriate CPAL host for the current platform.
+/// On Linux, uses ALSA host. On other platforms, uses the default host.
+pub fn get_cpal_host() -> cpal::Host {
+    #[cfg(target_os = "linux")]
+    {
+        cpal::host_from_id(cpal::HostId::Alsa).unwrap_or_else(|_| cpal::default_host())
+    }
+    #[cfg(not(target_os = "linux"))]
+    {
+        use cpal::traits::HostTrait;
+        cpal::default_host()
+    }
+}