App architecture modifications.

Now GUI and the app itself is divided into two different binaries.
The app also provides system tray icon.
Whereas the GUI can be used to configure the app.

app/src/stt/vosk.rs

@@ -0,0 +1,63 @@
+use once_cell::sync::OnceCell;
+use vosk::{DecodingState, Model, Recognizer};
+
+use std::sync::Mutex;
+
+use crate::config::VOSK_MODEL_PATH;
+
+static MODEL: OnceCell<Model> = OnceCell::new();
+static RECOGNIZER: OnceCell<Mutex<Recognizer>> = OnceCell::new();
+
+pub fn init_vosk() {
+    if !RECOGNIZER.get().is_none() {return;} // already initialized
+
+    let model = Model::new(VOSK_MODEL_PATH).unwrap();
+    let mut recognizer = Recognizer::new(&model, 16000.0).unwrap();
+
+    recognizer.set_max_alternatives(10);
+    recognizer.set_words(true);
+    recognizer.set_partial_words(true);
+
+    MODEL.set(model);
+    RECOGNIZER.set(Mutex::new(recognizer));
+}
+
+pub fn recognize(data: &[i16], include_partial: bool) -> Option<String> {
+    let state = RECOGNIZER.get().unwrap().lock().unwrap().accept_waveform(data);
+
+    match state {
+        DecodingState::Running => {
+            if include_partial {
+                Some(RECOGNIZER.get().unwrap().lock().unwrap().partial_result().partial.into())
+            } else {
+                None
+            }
+        }
+        DecodingState::Finalized => {
+            // Result will always be multiple because we called set_max_alternatives
+            Some(
+                RECOGNIZER.get().unwrap().lock().unwrap()
+                    .result()
+                    .multiple()
+                    .unwrap()
+                    .alternatives
+                    .first()
+                    .unwrap()
+                    .text
+                    .into(),
+            )
+        }
+        DecodingState::Failed => None,
+    }
+}
+
+// pub fn stereo_to_mono(input_data: &[i16]) -> Vec<i16> {
+//     let mut result = Vec::with_capacity(input_data.len() / 2);
+//     result.extend(
+//         input_data
+//             .chunks_exact(2)
+//             .map(|chunk| chunk[0] / 2 + chunk[1] / 2),
+//     );
+
+//     result
+// }