Update: Refactored the code

src/file_manager.py

@@ -0,0 +1,41 @@
+import os
+
+from pydub import AudioSegment
+from pytube import YouTube
+
+
+class FileManager:
+    def __init__(self):
+        pass
+
+    def download_youtube_audio(self, youtube_link, filename):
+        yt = YouTube(youtube_link)
+
+        # Get the highest quality audio stream
+        audio_stream = yt.streams.get_audio_only()
+
+        # Download if the file doesn't already exist
+        if not os.path.exists(filename):
+            audio_stream.download(filename=filename)
+
+    def convert_to_wav(self, mp4_file, wav_file):
+        sound = AudioSegment.from_file(mp4_file, format="mp4")
+        sound.export(wav_file, format="wav")
+
+    def load_local_file(self, local_file_path):
+        # Check the file type
+        ext = os.path.splitext(local_file_path)[-1].lower()
+
+        if ext == ".mp4":
+            wav_file = local_file_path.replace(".mp4", ".wav")
+            self.convert_to_wav(local_file_path, wav_file)
+            return wav_file
+        elif ext == ".mp3":
+            wav_file = local_file_path.replace(".mp3", ".wav")
+            audio = AudioSegment.from_file(local_file_path, format="mp3")
+            audio.export(wav_file, format="wav")
+            return wav_file
+        elif ext == ".wav":
+            return local_file_path
+        else:
+            raise ValueError("Unsupported file format.")