expand XAutoPF functionality (#57)

* create xautopf playlist parser and move current parsing logic to it

* refactor xautopf save logic to parser

* add limiter and sorter parsers

* add matcher parser

* add parser save test

* add default xml for XAutoPF files

docs/release-history.rst

@@ -43,6 +43,11 @@ Added
 * Introduced :py:class:`.MusifyItemSettable` class to allow distinction
   between items that can have their properties set and those that can't
 * Extend :py:class:`.FilterMatcher` with group_by tag functionality
+* Now fully supports parsing of processors relating to XAutoPF objects with full I/O of settings
+  to/from their related XML files on disk.
+* Now supports creating new XAutoPF files from scratch without the file needing to already exist.
+  For XML values not directly controlled by Musify, users can use the 'default_xml' class attribute
+  to control the initial default values applied in this scenario.
 
 Changed
 -------
@@ -62,6 +67,10 @@ Changed
   + prioritises fields settings over shuffle settings
 * :py:meth:`.Comparer._in_range` now uses inclusive range i.e. ``a <= x <= b`` where ``x`` is the value to compare
   and ``a`` and ``b`` are the limits. Previously used exclusive range i.e. ``a < x < b``
+* Removed ``from_xml`` and ``to_xml`` methods from all :py:class:`.MusicBeeProcessor` subclasses.
+  Moved this logic to :py:class:`.XMLPlaylistParser` as distinct 'get' methods for each processor type.
+* Moved loading of XML file logic from :py:class:`.XAutoPF` to :py:class:`.XMLPlaylistParser`.
+  :py:class:`.XMLPlaylistParser` is now solely responsible for all XML parsing and handling for XAutoPF files
 
 Fixed
 -----

musify/core/printer.py

@@ -19,15 +19,16 @@ class PrettyPrinter(ABC):
 
     @staticmethod
     def _pascal_to_snake(value: str) -> str:
-        """Convert snake_case to CamelCase."""
+        """Convert PascalCase to snake_case."""
         value = re.sub(r"([A-Z])", lambda m: f"_{m.group(1).lower()}", value.strip("_ "))
         value = re.sub(r"[_ ]+", "_", value).strip("_ ")
         return value.lower()
 
     @staticmethod
     def _snake_to_pascal(value: str) -> str:
-        """Convert snake_case to CamelCase."""
-        return re.sub(r"_(.)", lambda m: m.group(1).upper(), value.strip())
+        """Convert snake_case to PascalCase."""
+        value = re.sub(r"_(.)", lambda m: m.group(1).upper(), value.strip().lower())
+        return re.sub(r"^(.)", lambda m: m.group(1).upper(), value.strip())
 
     @abstractmethod
     def as_dict(self) -> dict[str, Any]:

musify/file/base.py

@@ -91,7 +91,7 @@ def save(self, dry_run: bool = True, *args, **kwargs) -> Any:
         """
         Save this object to file.
 
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         """
         raise NotImplementedError
 

musify/libraries/local/collection.py

@@ -119,7 +119,7 @@ def save_tracks(
 
         :param tags: Tags to be updated.
         :param replace: Destructively replace tags in each file.
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         :return: A map of the :py:class:`LocalTrack` saved to its result as a :py:class:`SyncResultTrack` object
         """
         bar = self.logger.get_progress_bar(iterable=self.tracks, desc="Updating tracks", unit="tracks")

musify/libraries/local/exception.py

@@ -43,8 +43,11 @@ def __init__(self, message: str | None = None, kind: str | None = None):
         super().__init__(formatted)
 
 
-class LocalProcessorError(LocalError):
-    """Exception raised for errors related to track processors."""
+###########################################################################
+## Track errors
+###########################################################################
+class TagError(LocalError):
+    """Exception raised for errors related to track tag errors."""
 
 
 ###########################################################################

musify/libraries/local/library/library.py

@@ -379,7 +379,7 @@ def save_playlists(self, dry_run: bool = True) -> dict[str, Result]:
         """
         For each Playlist in this Library, saves its associate tracks and its settings (if applicable) to file.
 
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         :return: A map of the playlist name to the results of its sync as a :py:class:`Result` object.
         """
         return {name: pl.save(dry_run=dry_run) for name, pl in self.playlists.items()}

musify/libraries/local/library/musicbee.py

@@ -151,7 +151,7 @@ def save(self, dry_run: bool = True, *_, **__) -> dict[str, Any]:
         """
         Generate and save the XML library file for this MusicBee library.
 
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         :return: Map representation of the saved XML file.
         """
         self.logger.debug(f"Save {self.name} library file: START")
@@ -509,7 +509,7 @@ def unparse(self, data: Mapping[str, Any], dry_run: bool = True) -> None:
         Un-parse a map of XML data to XML and save to file.
 
         :param data: Map of XML data to export.
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         """
         et: etree._ElementTree = etree.parse(self.path)
         parsed: dict[str, Any] = xmltodict.parse(etree.tostring(et.getroot(), encoding='utf-8', method='xml'))

musify/libraries/local/playlist/base.py

@@ -139,7 +139,7 @@ def save(self, dry_run: bool = True, *args, **kwargs) -> Result:
         """
         Write the tracks in this Playlist and its settings (if applicable) to file.
 
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         :return: :py:class:`Result` object with stats on the changes to the playlist.
         """
         raise NotImplementedError

musify/libraries/local/playlist/m3u.py

@@ -114,7 +114,7 @@ def save(self, dry_run: bool = True, *_, **__) -> SyncResultM3U:
         """
         Write the tracks in this Playlist and its settings (if applicable) to file.
 
-        :param dry_run: Run function, but do not modify file at all.
+        :param dry_run: Run function, but do not modify the file on the disk.
         :return: The results of the sync as a :py:class:`SyncResultM3U` object.
         """
         start_paths = {path.casefold() for path in self.path_mapper.unmap_many(self._original, check_existence=False)}