From 153421f00e2d3a4cf2dad6f6e1fd9d61452c34ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Elberte=20Pl=C3=ADnio?= <elberte.dev@gmail.com>
Date: Thu, 23 Jul 2026 22:34:37 -0300
Subject: [PATCH] fix(stt): auto-detect .en and other ggml model variants

---
 docs/releases/UNRELEASED.md |  5 +++
 src/engine/stt.rs           | 83 ++++++++++++++++++++++++++++++++-----
 2 files changed, 77 insertions(+), 11 deletions(-)

diff --git a/docs/releases/UNRELEASED.md b/docs/releases/UNRELEASED.md
index fdc8534..78f964e 100644
--- a/docs/releases/UNRELEASED.md
+++ b/docs/releases/UNRELEASED.md
@@ -21,6 +21,8 @@ then reset this file.
   preserves completed segments and only re-transcribes the unfinished tail.
 - PickScribe now finds `whisper-cli` in `~/.local/bin` when desktop sessions omit
   that directory from `PATH`.
+- Whisper model auto-detection now recognizes English-only `.en` models and
+  other `ggml-*.bin` variants in the standard local model directory.
 - Double-clicking empty titlebar space now maximizes or restores the window.
 - On Linux, the float capsule now keeps its glow visible without capturing
   clicks in the transparent margin. Other platforms keep a snug window to
@@ -101,6 +103,9 @@ then reset this file.
 
 ### Tested
 
+- Whisper model auto-detection fix: `cargo test` and `cargo clippy --workspace
+  --all-targets -- -D warnings`. Live-verified the installed
+  `~/.local/share/whisper.cpp/models/ggml-base.en.bin` model is selected.
 - pickscribe#66 PR 2 (macOS audio capture via ffmpeg/avfoundation): `cargo
   test` (workspace root, 122 tests including new `recorder_args` and
   `platform` coverage), `cargo test --manifest-path src-tauri/Cargo.toml` (37
diff --git a/src/engine/stt.rs b/src/engine/stt.rs
index 103fb1e..50fda77 100644
--- a/src/engine/stt.rs
+++ b/src/engine/stt.rs
@@ -43,17 +43,8 @@ pub fn detect_model_path() -> Option<PathBuf> {
     }
     let home = std::env::var("HOME").ok()?;
     let model_dir = PathBuf::from(&home).join(".local/share/whisper.cpp/models");
-    for name in [
-        "ggml-large-v3-turbo.bin",
-        "ggml-large-v3-turbo-q5_0.bin",
-        "ggml-small.bin",
-        "ggml-base.bin",
-        "ggml-tiny.bin",
-    ] {
-        let candidate = model_dir.join(name);
-        if candidate.is_file() {
-            return Some(candidate);
-        }
+    if let Some(path) = detect_model_in_dir(&model_dir) {
+        return Some(path);
     }
     // Arch whisper.cpp-model-* packages
     if let Ok(entries) = fs::read_dir("/usr/share") {
@@ -75,6 +66,39 @@ pub fn detect_model_path() -> Option<PathBuf> {
     None
 }
 
+fn detect_model_in_dir(model_dir: &Path) -> Option<PathBuf> {
+    for name in [
+        "ggml-large-v3-turbo.bin",
+        "ggml-large-v3-turbo-q5_0.bin",
+        "ggml-small.bin",
+        "ggml-small.en.bin",
+        "ggml-base.bin",
+        "ggml-base.en.bin",
+        "ggml-tiny.bin",
+        "ggml-tiny.en.bin",
+    ] {
+        let candidate = model_dir.join(name);
+        if candidate.is_file() {
+            return Some(candidate);
+        }
+    }
+
+    let mut models = fs::read_dir(model_dir)
+        .ok()?
+        .flatten()
+        .map(|entry| entry.path())
+        .filter(|path| {
+            path.is_file()
+                && path
+                    .file_name()
+                    .is_some_and(|name| name.to_string_lossy().starts_with("ggml-"))
+                && path.extension().is_some_and(|extension| extension == "bin")
+        })
+        .collect::<Vec<_>>();
+    models.sort();
+    models.into_iter().next()
+}
+
 /// List models available in the default model directory (for the settings UI).
 pub fn available_models() -> Vec<PathBuf> {
     let mut out = Vec::new();
@@ -303,6 +327,43 @@ fn parse_progress_percentage(line: &str) -> Option<u8> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn detects_english_model_from_preference_list() {
+        let dir = tempfile::tempdir().unwrap();
+        let model = dir.path().join("ggml-base.en.bin");
+        fs::write(&model, []).unwrap();
+
+        assert_eq!(detect_model_in_dir(dir.path()), Some(model));
+    }
+
+    #[test]
+    fn detects_unknown_model_by_sorted_filename() {
+        let dir = tempfile::tempdir().unwrap();
+        let first = dir.path().join("ggml-foo.bin");
+        fs::write(dir.path().join("ggml-zeta.bin"), []).unwrap();
+        fs::write(&first, []).unwrap();
+
+        assert_eq!(detect_model_in_dir(dir.path()), Some(first));
+    }
+
+    #[test]
+    fn returns_none_for_empty_model_directory() {
+        let dir = tempfile::tempdir().unwrap();
+
+        assert_eq!(detect_model_in_dir(dir.path()), None);
+    }
+
+    #[test]
+    fn respects_model_preference_order() {
+        let dir = tempfile::tempdir().unwrap();
+        let preferred = dir.path().join("ggml-small.bin");
+        fs::write(dir.path().join("ggml-base.bin"), []).unwrap();
+        fs::write(dir.path().join("ggml-small.en.bin"), []).unwrap();
+        fs::write(&preferred, []).unwrap();
+
+        assert_eq!(detect_model_in_dir(dir.path()), Some(preferred));
+    }
+
     #[test]
     fn parses_whisper_progress_percentages() {
         assert_eq!(