grooveondemand/groove/playlist.py
2022-12-06 22:17:53 -08:00

303 lines
9.5 KiB
Python

import logging
import os
from typing import Union, List
from groove import db
from groove.editor import PlaylistEditor, EDITOR_TEMPLATE
from groove.exceptions import PlaylistImportError
from slugify import slugify
from sqlalchemy import func, delete
from sqlalchemy.orm.session import Session
from sqlalchemy.engine.row import Row
from sqlalchemy.exc import NoResultFound, MultipleResultsFound
class Playlist:
"""
CRUD operations and convenience methods for playlists.
"""
def __init__(self,
slug: str,
session: Session,
name: str = '',
description: str = '',
create_ok=True):
self._session = session
self._slug = slug
self._name = name
self._description = description
self._entries = None
self._record = None
self._create_ok = create_ok
self._deleted = False
self._editor = PlaylistEditor()
@property
def deleted(self) -> bool:
return self._deleted
@property
def exists(self) -> bool:
if self.deleted:
logging.debug("Playlist has been deleted.")
return False
if not self._record:
if self._create_ok:
return True and self.record
return False
return True
@property
def editor(self):
return self._editor
@property
def name(self):
return self._name
@property
def description(self):
return self._description
@property
def summary(self):
return ' :: '.join([
f"[ {self.record.id} ]",
self.record.name,
f"http://{os.environ['HOST']}/{self.slug}",
])
@property
def slug(self) -> str:
return self._slug
@property
def session(self) -> Session:
return self._session
@property
def record(self) -> Union[Row, None]:
"""
Cache the playlist row from the database and return it. Optionally create it if it doesn't exist.
"""
if not self._record:
self._record = self.get_or_create()
return self._record
@property
def entries(self) -> Union[List, None]:
"""
Cache the list of entries on this playlist and return it.
"""
if self.record and not self._entries:
query = self.session.query(
db.entry,
db.track
).filter(
(db.playlist.c.id == self.record.id)
).filter(
db.entry.c.playlist_id == db.playlist.c.id
).filter(
db.entry.c.track_id == db.track.c.id
).order_by(
db.entry.c.track
)
self._entries = query.all()
return self._entries
@property
def as_dict(self) -> dict:
"""
Return a dictionary of the playlist and its entries.
"""
if not self.exists:
return {}
playlist = dict(self.record)
playlist['entries'] = [dict(entry) for entry in self.entries]
return playlist
@property
def as_string(self) -> str:
if not self.exists:
return ''
text = f"{self.summary}\n"
for entry in self.entries:
text += f" - {entry.track} {entry.artist} - {entry.title}\n"
return text
@property
def as_yaml(self) -> str:
template_vars = self.as_dict
template_vars['entries'] = ''
for entry in self.entries:
template_vars['entries'] += f" - {entry.artist} - {entry.title}\n"
return EDITOR_TEMPLATE.format(**template_vars)
def _get_tracks_by_path(self, paths: List[str]) -> List:
"""
Retrieve tracks from the database that match the specified path fragments. The exceptions NoResultFound and
MultipleResultsFound are expected in the case of no matches and multiple matches, respectively.
"""
return [self.session.query(db.track).filter(db.track.c.relpath.ilike(f"%{path}%")).one() for path in paths]
def edit(self):
edits = self.editor.edit(self)
if not edits:
return
new = Playlist.from_yaml(edits, self.session)
if new == self:
logging.debug("No changes detected.")
return
logging.debug(f"Updating {self.slug} with new edits.")
self._slug = new.slug
self._name = new.name.strip()
self._description = new.description.strip()
self._record = self.save()
def add(self, paths: List[str]) -> int:
"""
Add entries to the playlist. Each path should match one and only one track in the database (case-insensitive).
If a path doesn't match any track, or if a path matches multiple tracks, nothing is added to the playlist.
Args:
paths (list): A list of partial paths to add.
Returns:
int: The number of tracks added.
"""
logging.debug(f"Attempting to add tracks matching: {paths}")
try:
return self.create_entries(self._get_tracks_by_path(paths))
except NoResultFound:
logging.error("One or more of the specified paths do not match any tracks in the database.")
return 0
except MultipleResultsFound:
logging.error("One or more of the specified paths matches multiple tracks in the database.")
return 0
def delete(self) -> Union[int, None]:
"""
Delete a playlist and its entries from the database, then clear the cached values.
"""
if not self.record:
return None
plid = self.record.id
stmt = delete(db.entry).where(db.entry.c.playlist_id == plid)
logging.debug(f"Deleting entries associated with playlist {plid}: {stmt}")
self.session.execute(stmt)
stmt = delete(db.playlist).where(db.playlist.c.id == plid)
logging.debug(f"Deleting playlist {plid}: {stmt}")
self.session.execute(stmt)
self.session.commit()
self._record = None
self._entries = None
self._deleted = True
return plid
def get_or_create(self, create_ok: bool = False) -> Row:
try:
return self._get()
except NoResultFound:
logging.debug(f"Could not find a playlist with slug {self.slug}.")
if self.deleted:
raise RuntimeError("Object has been deleted.")
if self._create_ok or create_ok:
return self.save()
def _get(self):
return self.session.query(db.playlist).filter(
db.playlist.c.slug == self.slug
).one()
def _insert(self, values):
stmt = db.playlist.insert(values)
results = self.session.execute(stmt)
self.session.commit()
logging.debug(f"Saved playlist with slug {self.slug}")
return self.session.query(db.playlist).filter(
db.playlist.c.id == results.inserted_primary_key[0]
).one()
def _update(self, values):
stmt = db.playlist.update().where(
db.playlist.c.id == self._record.id
).values(values)
self.session.execute(stmt)
self.session.commit()
return self.session.query(db.playlist).filter(
db.playlist.c.id == self._record.id
).one()
def save(self) -> Row:
values = {
'slug': self.slug,
'name': self.name,
'description': self.description
}
logging.debug(f"Saving values: {values}")
obj = self._update(values) if self._record else self._insert(values)
logging.debug(f"Saved playlist {obj.id} with slug {obj.slug}")
return obj
def load(self):
self.get_or_create(create_ok=False)
return self
def create_entries(self, tracks: List[Row]) -> int:
"""
Append a list of tracks to a playlist by populating the entries table with records referencing the playlist and
the specified tracks.
Args:
tracks (list): A list of Row objects from the track table.
Returns:
int: The number of tracks added.
"""
maxtrack = self.session.query(func.max(db.entry.c.track)).filter_by(
playlist_id=self.record.id
).one()[0] or 0
self.session.execute(
db.entry.insert(),
[
{'playlist_id': self.record.id, 'track_id': obj.id, 'track': idx}
for (idx, obj) in enumerate(tracks, start=maxtrack+1)
]
)
self.session.commit()
self._entries = None
return len(tracks)
@classmethod
def from_row(cls, row, session):
pl = Playlist(slug=row.slug, session=session)
pl._record = row
return pl
@classmethod
def from_yaml(cls, source, session):
try:
name = list(source.keys())[0].strip()
description = (source[name]['description'] or '').strip()
return Playlist(
slug=slugify(name),
name=name,
description=description,
session=session,
)
except (IndexError, KeyError):
PlaylistImportError("The specified source was not a valid playlist.")
def __eq__(self, obj):
for key in ('slug', 'name', 'description'):
if getattr(obj, key) != getattr(self, key):
logging.debug(f"{key}: {getattr(obj, key)} != {getattr(self, key)}")
return False
return True
def __repr__(self):
return self.as_string