feat(srt translation): add api for srt translation

app/utils/srt_parser.py

@@ -0,0 +1,83 @@
+
+import re
+import os
+from typing import List
+from app.models.srt_translation import SRTSubtitle
+
+def parse_srt_file(file_path: str) -> List[SRTSubtitle]:
+    """
+    Parse SRT file and return list of subtitle objects
+    """
+    subtitles = []
+    
+    try:
+        with open(file_path, 'r', encoding='utf-8') as file:
+            content = file.read()
+        
+        print(f"🔍 Read file content, length: {len(content)} characters")
+        
+        # More robust SRT parsing
+        blocks = [block.strip() for block in content.split('\n\n') if block.strip()]
+        print(f"🔍 Found {len(blocks)} blocks")
+        
+        for block in blocks:
+            lines = [line.strip() for line in block.split('\n') if line.strip()]
+            
+            if len(lines) >= 3:
+                try:
+                    index = int(lines[0])
+                    timestamp = lines[1]
+                    
+                    # Handle multi-line text
+                    text_lines = lines[2:]
+                    text = ' '.join(text_lines)  # Join multiple lines with space
+                    
+                    subtitle = SRTSubtitle(
+                        index=index,
+                        timestamp=timestamp,
+                        japanese_text=text
+                    )
+                    subtitles.append(subtitle)
+                    
+                    print(f"🔍 Parsed subtitle {index}: '{text}'")
+                    
+                except (ValueError, IndexError) as e:
+                    print(f"⚠️  Failed to parse block: {lines[0] if lines else 'empty'}, error: {e}")
+                    continue
+            else:
+                print(f"⚠️  Skipping invalid block with {len(lines)} lines: {lines}")
+                
+    except Exception as e:
+        print(f"❌ Error reading file: {str(e)}")
+        import traceback
+        traceback.print_exc()
+    
+    print(f"🔍 Successfully parsed {len(subtitles)} subtitles")
+    return subtitles
+
+def write_translated_srt(subtitles: List[SRTSubtitle], output_path: str):
+    """
+    Write translated subtitles back to SRT format
+    """
+    try:
+        # Create directory if it doesn't exist
+        os.makedirs(os.path.dirname(output_path), exist_ok=True)
+        
+        with open(output_path, 'w', encoding='utf-8') as file:
+            for subtitle in subtitles:
+                file.write(f"{subtitle.index}\n")
+                file.write(f"{subtitle.timestamp}\n")
+                if subtitle.english_translation:
+                    file.write(f"{subtitle.japanese_text}\n")
+                    file.write(f"{subtitle.english_translation}\n")
+                else:
+                    file.write(f"{subtitle.japanese_text}\n")
+                file.write("\n")
+        
+        print(f"✅ Successfully wrote {len(subtitles)} subtitles to: {output_path}")
+        
+    except Exception as e:
+        print(f"❌ Error writing SRT file: {str(e)}")
+        import traceback
+        traceback.print_exc()
+        raise