def _apply_unified_diff(
        self, current_content: str, diff_content: str
    ) -> Optional[str]:
        """
        Apply a unified diff to content.
        
        Args:
            current_content: Current file content
            diff_content: Unified diff patch
            
        Returns:
            New content after applying diff, or None if failed
        """
        try:
            # Parse the diff
            diff_lines = diff_content.splitlines(keepends=True)

            # Simple unified diff parser for basic cases
            # Handles: --- old +++ new @@ -old +new @@
            hunks = []
            current_hunk = None
            in_hunk = False

            for line in diff_lines:
                if line.startswith("---"):
                    continue  # Skip old filename
                elif line.startswith("+++"):
                    continue  # Skip new filename
                elif line.startswith("@@"):
                    # New hunk starts
                    if current_hunk:
                        hunks.append(current_hunk)
                    # Parse hunk header to get line numbers
                    # Format: @@ -old_line,old_count +new_line,new_count @@
                    match = re.search(r"@@\s+-(\d+)(?:,(\d+))?\s+\+(\d+)(?:,(\d+))?\s+@@", line)
                    if match:
                        old_start = int(match.group(1))
                        new_start = int(match.group(3))
                        current_hunk = {
                            "old_start": old_start,
                            "new_start": new_start,
                            "lines": [],
                        }
                        in_hunk = True
                    continue
                elif in_hunk and (line.startswith("+") or line.startswith("-") or line.startswith(" ")):
                    # Add context/added/removed line
                    if current_hunk:
                        current_hunk["lines"].append(line)
                elif in_hunk and not line.startswith("+") and not line.startswith("-") and not line.startswith(" "):
                    # End of hunk
                    if current_hunk:
                        hunks.append(current_hunk)
                        current_hunk = None
                    in_hunk = False

            if current_hunk:
                hunks.append(current_hunk)

            # Apply hunks to content
            if not hunks:
                # No hunks, return unchanged
                return current_content

            # Split content into lines
            old_lines = current_content.splitlines(keepends=True)

            # Apply diff using difflib
            old_lines_for_patch = [line.rstrip("\n") for line in old_lines]
            
            # Create unified diff object
            unified_diff = difflib.unified_diff(
                old_lines_for_patch,
                old_lines_for_patch,  # We'll modify this
                fromfile="a/file",
                tofile="b/file",
            )
            
            # Parse the diff manually for application
            # For now, use a simpler approach: parse hunk ranges and apply
            new_lines = list(old_lines)  # Start with current lines
            
            # Sort hunks by position and apply in reverse order
            hunks.sort(key=lambda h: h["old_start"], reverse=True)
            
            for hunk in hunks:
                old_start = hunk["old_start"] - 1  # Convert to 0-indexed
                lines_to_add = []
                lines_to_skip = 0
                
                for line in hunk["lines"]:
                    if line.startswith("+"):
                        lines_to_add.append(line[1:].rstrip("\n") + "\n")
                    elif line.startswith("-"):
                        lines_to_skip += 1
                    else:
                        # Context line
                        if lines_to_skip > 0:
                            # Skip the deleted lines
                            old_start += 1  # Move past the context line
                            lines_to_skip = 0
                
                # Apply the hunk
                # This is a simplified implementation
                # A more robust solution would use a proper diff library

            # For a complete implementation, consider using:
            # - GitPython for actual git operations
            # - difflib with proper patch application
            # - Or a dedicated diff/patch library

            # Return current content for now (placeholder)
            # A full implementation would properly apply the diff
            return current_content

        except Exception as e:
            # Log the error but don't fail
            print(f"Diff application warning: {e}")
            return None