87 lines
3.3 KiB
Python
87 lines
3.3 KiB
Python
"""
|
|
Author: Uyanide pywang0608@foxmail.com
|
|
Date: 2026-04-10 08:14:41
|
|
Description: Debounced lyric fetch orchestration for watch session.
|
|
"""
|
|
|
|
import asyncio
|
|
from typing import Awaitable, Callable, Optional
|
|
|
|
from ..lrc import LRCData
|
|
from ..models import TrackMeta
|
|
|
|
|
|
class LyricFetcher:
|
|
"""Debounces track updates and runs at most one lyric fetch task at a time."""
|
|
|
|
_watch_debounce_ms: int
|
|
_fetch_func: Callable[[TrackMeta], Awaitable[Optional[LRCData]]]
|
|
_on_fetching: Callable[[], Awaitable[None] | None]
|
|
_on_result: Callable[[Optional[LRCData]], Awaitable[None] | None]
|
|
_debounce_task: asyncio.Task | None
|
|
_fetch_task: asyncio.Task | None
|
|
_pending_track: TrackMeta | None
|
|
|
|
def __init__(
|
|
self,
|
|
fetch_func: Callable[[TrackMeta], Awaitable[Optional[LRCData]]],
|
|
on_fetching: Callable[[], Awaitable[None] | None],
|
|
on_result: Callable[[Optional[LRCData]], Awaitable[None] | None],
|
|
watch_debounce_ms: int,
|
|
) -> None:
|
|
"""Initialize fetch callbacks and runtime options."""
|
|
self._watch_debounce_ms = watch_debounce_ms
|
|
self._fetch_func = fetch_func
|
|
self._on_fetching = on_fetching
|
|
self._on_result = on_result
|
|
self._debounce_task: asyncio.Task | None = None
|
|
self._fetch_task: asyncio.Task | None = None
|
|
self._pending_track: TrackMeta | None = None
|
|
|
|
async def stop(self) -> None:
|
|
"""Cancel and await all in-flight debounce/fetch tasks."""
|
|
for task in (self._debounce_task, self._fetch_task):
|
|
if task is not None:
|
|
task.cancel()
|
|
await asyncio.gather(
|
|
*[t for t in (self._debounce_task, self._fetch_task) if t is not None],
|
|
return_exceptions=True,
|
|
)
|
|
self._debounce_task = None
|
|
self._fetch_task = None
|
|
|
|
def request(self, track: TrackMeta) -> None:
|
|
"""Request lyrics for track with debounce collapsing."""
|
|
self._pending_track = track
|
|
if self._debounce_task is not None:
|
|
# cancel any pending debounce window — the new request supersedes it
|
|
self._debounce_task.cancel()
|
|
self._debounce_task = asyncio.create_task(self._debounce_then_fetch())
|
|
|
|
async def _debounce_then_fetch(self) -> None:
|
|
"""Wait debounce window then start a fresh fetch task for latest pending track."""
|
|
await asyncio.sleep(self._watch_debounce_ms / 1000.0)
|
|
track = self._pending_track
|
|
if track is None:
|
|
return
|
|
|
|
if self._fetch_task is not None:
|
|
# abort any in-flight fetch for a previous track before starting the new one
|
|
self._fetch_task.cancel()
|
|
await asyncio.gather(self._fetch_task, return_exceptions=True)
|
|
|
|
self._fetch_task = asyncio.create_task(self._do_fetch(track))
|
|
|
|
async def _do_fetch(self, track: TrackMeta) -> None:
|
|
"""Execute fetch lifecycle callbacks and fetch lyrics for a track."""
|
|
# callbacks may be plain functions or coroutines — handle both
|
|
fetching_callback_result = self._on_fetching()
|
|
if asyncio.iscoroutine(fetching_callback_result):
|
|
await fetching_callback_result
|
|
|
|
lyrics = await self._fetch_func(track)
|
|
|
|
result_callback_result = self._on_result(lyrics)
|
|
if asyncio.iscoroutine(result_callback_result):
|
|
await result_callback_result
|