Rework ID3v2 user text frame abstractions [#22]

* Add ``ID3v2UserText`` class.
* Change ``ID3v2UserTextFrame`` to have only value attribute.
  that contains a single user text object.
* Change ``ID3v2Frames`` to present a list of user text
  objects for ``TXXX`` key.

CHANGELOG.md

@@ -41,6 +41,7 @@ This project adheres to [Semantic Versioning](https://semver.org).
 * ``ID3v2GeneralEncapsulatedObject``.
 * ``ID3v2PrivateInfo``.
 * ``ID3v2UserURLLink``.
+* ``ID3v2UserText``.
 
 ### Changed
 
@@ -71,6 +72,12 @@ This project adheres to [Semantic Versioning](https://semver.org).
 		that contains a single user URL link object.
 	* Change ``ID3v2Frames`` to present a list of user URL link
 		objects for ``WXXX`` key.
+* Rework ID3v2 user text frame abstractions.
+	* Add ``ID3v2UserText`` class.
+	* Change ``ID3v2UserTextFrame`` to have only value attribute.
+		that contains a single user text object.
+	* Change ``ID3v2Frames`` to present a list of user text
+		objects for ``TXXX`` key.
 
 ### Removed
 

src/audio_metadata/formats/id3v2.py

@@ -250,7 +250,7 @@ def parse(cls, data, id3_version):
 						f"Ignoring '{frame.id}' frame with value '{frame.value}'.\n"
 						f"'{frame.id}' is not supported in the ID3v2.{id3_version.value[1]} specification.\n"
 					),
-					AudioMetadataWarning
+					AudioMetadataWarning,
 				)
 				continue
 
@@ -264,11 +264,6 @@ def parse(cls, data, id3_version):
 				),
 			):
 				frames[f'{frame.id}:{frame.description}:{frame.language}'].append(frame.value)
-			elif isinstance(
-				frame,
-				ID3v2UserTextFrame,
-			):
-				frames[f'{frame.id}:{frame.description}'].append(frame.value)
 			elif isinstance(
 				frame,
 				(

src/audio_metadata/formats/id3v2_frames.py

@@ -23,6 +23,7 @@
 	'ID3v2TimestampFrame',
 	'ID3v2UnsynchronizedLyricsFrame',
 	'ID3v2URLLinkFrame',
+	'ID3v2UserText',
 	'ID3v2UserTextFrame',
 	'ID3v2UserURLLink',
 	'ID3v2UserURLLinkFrame',
@@ -111,6 +112,15 @@ class ID3v2PrivateInfo(AttrMapping):
 	data = attrib()
 
 
+@attrs(
+	repr=False,
+	kw_only=True,
+)
+class ID3v2UserText(AttrMapping):
+	description = attrib()
+	text = attrib()
+
+
 @attrs(
 	repr=False,
 	kw_only=True,
@@ -319,7 +329,6 @@ class ID3v2UserURLLinkFrame(ID3v2BaseFrame):
 	kw_only=True,
 )
 class ID3v2UserTextFrame(ID3v2BaseFrame):
-	description = attrib()
 	value = attrib()
 
 
@@ -711,6 +720,14 @@ def parse(cls, data, struct_pattern, size_len, per_byte):
 			kwargs['value'] = decode_bytestring(description, encoding)
 		elif frame_type is ID3v2URLLinkFrame:
 			kwargs['value'] = unquote(decode_bytestring(frame_data))
+		elif frame_type is ID3v2UserTextFrame:
+			encoding = determine_encoding(frame_data)
+
+			description, text = split_encoded(frame_data[1:], encoding)
+			kwargs['value'] = ID3v2UserText(
+				description=decode_bytestring(description, encoding),
+				text=decode_bytestring(text, encoding),
+			)
 		elif frame_type is ID3v2UserURLLinkFrame:
 			encoding = determine_encoding(frame_data)
 
@@ -719,13 +736,7 @@ def parse(cls, data, struct_pattern, size_len, per_byte):
 				description=decode_bytestring(description, encoding),
 				url=unquote(decode_bytestring(url)),
 			)
-		elif issubclass(
-			frame_type,
-			(
-				ID3v2NumberFrame,
-				ID3v2UserTextFrame,
-			),
-		):
+		elif issubclass(frame_type, ID3v2NumberFrame):
 			encoding = determine_encoding(frame_data[0:1])
 			kwargs['value'] = decode_bytestring(frame_data[1:], encoding)
 		elif issubclass(