Initial commit. Basic featues are implemented

metadata.py

@@ -0,0 +1,99 @@
+"""Metadata selection and building."""
+
+
+def select_album_value(track, input_metadata, args):
+    """
+    Determine the album value according to precedence.
+
+    Precedence: --album > %al > original album > original title > None.
+
+    Args:
+        track: Dict of parsed track data.
+        input_metadata: Dict from get_metadata().
+        args: Parsed command‑line arguments.
+
+    Returns:
+        Album string or None.
+    """
+    original_album = input_metadata.get('album')
+    original_title = input_metadata.get('title')
+
+    if args.album:
+        return args.album
+    elif track.get('al'):
+        return track.get('al')
+    elif original_album:
+        return original_album
+    elif original_title:
+        return original_title
+    else:
+        return None
+
+
+def select_comment_value(input_metadata, args):
+    """
+    Determine the comment value according to precedence.
+
+    Precedence: --no-comment > --comment > --merge-comments >
+    --comment-stream > first comment from file.
+
+    Args:
+        input_metadata: Dict from get_metadata().
+        args: Parsed command‑line arguments.
+
+    Returns:
+        Comment string or None.
+    """
+    original_comments = input_metadata.get('comments', [])
+
+    if args.no_comment:
+        return None
+    elif args.comment:
+        return args.comment
+    elif args.merge_comments and original_comments:
+        separator = args.comment_separator if args.comment_separator else '; '
+        comments_text = separator.join(comment for _, comment in original_comments)
+        return comments_text if comments_text else None
+    elif args.comment_stream is not None:
+        if 0 <= args.comment_stream < len(original_comments):
+            return original_comments[args.comment_stream][1]
+        else:
+            print(f"Warning: Stream {args.comment_stream} not found in comments list. "
+                  f"Using first comment (if any).")
+            if original_comments:
+                return original_comments[0][1]
+            return None
+    elif original_comments:
+        # Default: use the first comment.
+        return original_comments[0][1]
+    else:
+        return None
+
+
+def build_metadata_dict(track, idx, input_metadata, args):
+    """
+    Assemble the final metadata dictionary for FFmpeg.
+
+    Args:
+        track: Dict of parsed track data.
+        idx: Track index (1‑based).
+        input_metadata: Dict from get_metadata().
+        args: Parsed command‑line arguments.
+
+    Returns:
+        Dict with metadata fields (empty values removed).
+    """
+    album_value = select_album_value(track, input_metadata, args)
+    comment_value = select_comment_value(input_metadata, args)
+
+    metadata = {
+        'title': track.get('tn', ''),
+        'artist': track.get('an', ''),
+        'album': album_value,
+        'date': track.get('date', ''),
+        'track': f"{idx:02d}",
+        'comment': comment_value
+    }
+
+    # Remove empty fields.
+    return {k: v for k, v in metadata.items() if v}