soulsync/core/download_plugins/base.py
Broque Thomas d17365296a Lift shared download dataclasses + boot via singleton factory
Two architectural cleanups on top of the download engine refactor.

(1) Shared dataclasses move to neutral plugin package.
TrackResult, AlbumResult, DownloadStatus, SearchResult lived in
core/soulseek_client.py for historical reasons — every other plugin
imported them from the soulseek module just to satisfy the contract,
coupling 8 clients to a sibling source for type imports only. Moved
them to the new core/download_plugins/types.py module and updated all
14 import sites across the deezer/hifi/lidarr/qobuz/soundcloud/tidal/
youtube clients, the engine, matching engine, redownload helper, and
tests. Clean break, no backward-compat re-export.

(2) web_server.py boots the orchestrator via the singleton factory.
After construction it now calls set_download_orchestrator(...) so
get_download_orchestrator() returns the same instance the global
handle points at instead of lazily building a separate orchestrator.
Matches the get_metadata_engine() pattern.
2026-05-05 09:08:39 -07:00

133 lines
5.2 KiB
Python

"""Canonical contract every download source plugin must satisfy.
`DownloadSourcePlugin` is a structural Protocol — any class that
implements these methods with matching signatures is automatically
treated as a download source. No inheritance required, no manual
registration required beyond the registry entry.
The protocol is intentionally narrow — only the methods the
orchestrator dispatches generically across all sources. Source-
specific extras (Soulseek's slskd internals, Lidarr's album-only
flow, etc.) stay on the underlying client and are accessed through
the registry's typed accessor.
This file is the FOUNDATION step. Existing client classes
(SoulseekClient, YouTubeClient, TidalDownloadClient, etc.) already
conform structurally — they grew the same shape independently
because every consumer site needed the same calls. This file just
makes the implicit contract explicit so:
- Type checkers can flag drift if a new source forgets a method.
- The orchestrator can iterate plugins generically instead of
hardcoding `[self.soulseek, self.youtube, ...]` everywhere.
- Future PRs can move shared logic INTO the contract (a base
class with default implementations) without changing the
signature surface every consumer already depends on.
"""
from __future__ import annotations
from typing import TYPE_CHECKING, List, Optional, Protocol, Tuple, runtime_checkable
# Soulseek client owns the canonical TrackResult / AlbumResult /
# DownloadStatus dataclasses — every other source already imports
# from there. We only need them for type annotations on this
# protocol; using TYPE_CHECKING avoids a circular import once the
# clients themselves inherit from DownloadSourcePlugin (Cin's
# review feedback — clients explicitly declare conformance instead
# of relying on structural typing).
if TYPE_CHECKING:
from core.download_plugins.types import AlbumResult, DownloadStatus, TrackResult
@runtime_checkable
class DownloadSourcePlugin(Protocol):
"""Structural contract for a download source.
`runtime_checkable` lets `isinstance(client, DownloadSourcePlugin)`
work for the conformance test, but it ONLY checks method names —
not signatures or async-ness. The conformance test in
``tests/test_download_plugin_conformance.py`` does the deeper
signature check.
"""
# ------------------------------------------------------------------
# Configuration / lifecycle
# ------------------------------------------------------------------
def is_configured(self) -> bool:
"""Return True iff this source has the credentials / settings
it needs to function. Used by the orchestrator to skip
unconfigured sources during hybrid fallback."""
...
async def check_connection(self) -> bool:
"""Probe the source's API / endpoint. Return True if the
source is reachable. May make a live network call."""
...
# ------------------------------------------------------------------
# Search
# ------------------------------------------------------------------
async def search(
self,
query: str,
timeout: Optional[int] = None,
progress_callback=None,
) -> Tuple[List[TrackResult], List[AlbumResult]]:
"""Search the source for tracks (and albums where supported).
Returns a tuple of (track_results, album_results). Either
list may be empty. Sources that don't expose album-level
search return ``[]`` as the second element.
"""
...
# ------------------------------------------------------------------
# Download
# ------------------------------------------------------------------
async def download(
self,
username: str,
filename: str,
file_size: int = 0,
) -> Optional[str]:
"""Kick off a download. Returns a download_id string the
caller can poll via ``get_download_status``. Returns ``None``
if the source can't / won't handle this download.
``username`` is the source-name string for streaming sources
(e.g. ``'youtube'``, ``'tidal'``) and the actual slskd peer
username for Soulseek. ``filename`` is source-specific —
Soulseek file path, YouTube ``video_id||title``, Tidal /
Qobuz ``track_id||display``, etc.
"""
...
async def get_all_downloads(self) -> List[DownloadStatus]:
"""Return live status of all downloads currently tracked by
this source. The orchestrator concatenates results from
every plugin to build the global download list."""
...
async def get_download_status(self, download_id: str) -> Optional[DownloadStatus]:
"""Return status for a single download or ``None`` if this
source doesn't know about that download_id."""
...
async def cancel_download(
self,
download_id: str,
username: Optional[str] = None,
remove: bool = False,
) -> bool:
"""Cancel an active download. ``remove=True`` also drops
the row from the source's active-downloads tracking."""
...
async def clear_all_completed_downloads(self) -> bool:
"""Drop completed downloads from active tracking. Sources
that don't keep completed history return True with no-op."""
...