feat: origin filename support.

src/file_finder.rs

@@ -21,17 +21,65 @@ pub fn find_largest_video_file(path: &Path) -> Result<PathBuf> {
 }
 
 pub fn find_audio_file(video_path: &Path) -> Result<PathBuf> {
-    let video_name = video_path.file_name().unwrap().to_str().unwrap();
-    let video_extension = video_path.extension().unwrap();
-    let audio_name = format!("{}.m4a", &video_name[..video_name.len() - video_extension.len() - 1]);
-    let audio_path = video_path.parent().unwrap().join(audio_name);
+    let parent = video_path.parent().unwrap();
+    let video_extension = video_path.extension().and_then(|e| e.to_str());
 
-    if !audio_path.exists() {
-        return Err(std::io::Error::new(
-            std::io::ErrorKind::NotFound,
-            format!("Audio file does not exist: {}", audio_path.display())
-        ));
+    // Try to find .m4a file first (old format)
+    let video_name = video_path.file_stem().and_then(|n| n.to_str()).unwrap_or("");
+    let audio_m4a_path = parent.join(format!("{}.m4a", video_name));
+    if audio_m4a_path.exists() {
+        return Ok(audio_m4a_path);
     }
 
-    Ok(audio_path)
+    // Try to find another .m4s file (new format)
+    if video_extension == Some("m4s") {
+        let mut audio_candidates = Vec::new();
+        for entry in std::fs::read_dir(parent)? {
+            let entry_path = entry?.path();
+            if entry_path.is_file() {
+                if let Some(ext) = entry_path.extension().and_then(|e| e.to_str()) {
+                    if ext == "m4s" && entry_path != video_path {
+                        let size = entry_path.metadata()?.len();
+                        audio_candidates.push((entry_path, size));
+                    }
+                }
+            }
+        }
+
+        if !audio_candidates.is_empty() {
+            // Return the largest .m4s file that's not the video file
+            audio_candidates.sort_by(|a, b| b.1.cmp(&a.1));
+            return Ok(audio_candidates[0].0.clone());
+        }
+    }
+
+    Err(std::io::Error::new(
+        std::io::ErrorKind::NotFound,
+        format!("Audio file does not exist. Looked for: {}", audio_m4a_path.display())
+    ))
+}
+
+pub fn find_ass_file(path: &Path) -> Result<PathBuf> {
+    for entry in std::fs::read_dir(path)? {
+        let entry_path = entry?.path();
+        if entry_path.is_file() {
+            if let Some(ext) = entry_path.extension().and_then(|e| e.to_str()) {
+                if ext == "ass" {
+                    return Ok(entry_path);
+                }
+            }
+        }
+    }
+
+    Err(std::io::Error::new(
+        std::io::ErrorKind::NotFound,
+        "ASS subtitle file not found in directory"
+    ))
+}
+
+pub fn get_output_name_from_ass(ass_path: &Path) -> String {
+    ass_path.file_stem()
+        .and_then(|n| n.to_str())
+        .unwrap_or("output")
+        .to_string()
 }