feat: add backup option and move some logic from main to utils

core/subtitles.py

@@ -1,7 +1,9 @@
 import os
 import re
+import shutil
 from typing import List
 
+from config import SYNC_CONFIG
 from .types import SubtitleEntry
 
 
@@ -41,9 +43,28 @@ class SubtitleHandler:
             entries.append(SubtitleEntry(int(match.group(1)), start, end, match.group(4).strip()))
         return entries
 
+    @staticmethod
+    def create_backup(filepath: str):
+        """Creates a .bak copy of the subtitles if one doesn't exist."""
+        backup_path = filepath + ".bak"
+        if not os.path.exists(backup_path):
+            try:
+                shutil.copy2(filepath, backup_path)
+                print(f"Backup created: {os.path.basename(backup_path)}")
+            except IOError as e:
+                print(f"Warning: Could not create backup: {e}")
+
     @staticmethod
     def write_srt(filepath: str, entries: List[SubtitleEntry]):
-        with open(filepath, 'w', encoding='utf-8') as f:
-            for entry in entries:
-                f.write(
-                    f"{entry.index}\n{SubtitleHandler.format_time(entry.start_ms)} --> {SubtitleHandler.format_time(entry.end_ms)}\n{entry.raw_text}\n\n")
+        # 1. Ensure backup exists before overwriting
+        if SYNC_CONFIG['create_backup']:
+            SubtitleHandler.create_backup(filepath)
+
+        # 2. Overwrite
+        try:
+            with open(filepath, 'w', encoding='utf-8') as f:
+                for entry in entries:
+                    f.write(
+                        f"{entry.index}\n{SubtitleHandler.format_time(entry.start_ms)} --> {SubtitleHandler.format_time(entry.end_ms)}\n{entry.raw_text}\n\n")
+        except IOError as e:
+            print(f"Error writing subtitle file: {e}")