mirror of
https://github.com/Dvorinka/SpotifyRecAlg.git
synced 2026-06-04 12:33:03 +00:00
Tomas Dvorak
130 lines
4.1 KiB
Python
130 lines
4.1 KiB
Python
from __future__ import annotations
|
|
|
|
from sqlalchemy import and_, func, select
|
|
|
|
from swingmusic.db.engine import DbEngine
|
|
from swingmusic.db.userdata import ScrobbleTable, SimilarArtistTable
|
|
from swingmusic.models.track import Track
|
|
from swingmusic.store.tracks import TrackStore
|
|
|
|
|
|
def _deterministic_float_from_hash(value: str) -> float:
|
|
# Stable pseudo-random signal for deterministic cold-start ranking.
|
|
if not value:
|
|
return 0.0
|
|
|
|
try:
|
|
sample = int(value[:8], 16)
|
|
except ValueError:
|
|
sample = sum(ord(ch) for ch in value)
|
|
|
|
return (sample % 1000) / 1000.0
|
|
|
|
|
|
def _get_user_track_play_counts(trackhashes: set[str], userid: int) -> dict[str, int]:
|
|
if not trackhashes:
|
|
return {}
|
|
|
|
with DbEngine.manager() as conn:
|
|
result = conn.execute(
|
|
select(ScrobbleTable.trackhash, func.count(ScrobbleTable.id).label("plays"))
|
|
.where(
|
|
and_(
|
|
ScrobbleTable.userid == userid,
|
|
ScrobbleTable.trackhash.in_(trackhashes),
|
|
)
|
|
)
|
|
.group_by(ScrobbleTable.trackhash)
|
|
)
|
|
rows = result.fetchall()
|
|
|
|
return {row.trackhash: int(row.plays) for row in rows}
|
|
|
|
|
|
def rank_tracks_for_user(tracks: list[Track], userid: int) -> list[Track]:
|
|
if not tracks:
|
|
return []
|
|
|
|
trackhashes = {track.trackhash for track in tracks}
|
|
play_counts = _get_user_track_play_counts(trackhashes, userid)
|
|
|
|
max_bitrate = max((track.bitrate for track in tracks), default=1)
|
|
max_play_count = max(play_counts.values(), default=0)
|
|
|
|
# Approximate recency from date tag where present (fallback to deterministic signal).
|
|
dates = [track.date for track in tracks if track.date and track.date > 0]
|
|
min_date = min(dates) if dates else 0
|
|
max_date = max(dates) if dates else 0
|
|
|
|
def base_score(track: Track) -> float:
|
|
bitrate_score = (track.bitrate / max_bitrate) if max_bitrate else 0.0
|
|
|
|
if max_date > min_date and track.date:
|
|
recency_score = (track.date - min_date) / (max_date - min_date)
|
|
else:
|
|
recency_score = _deterministic_float_from_hash(track.trackhash)
|
|
|
|
variety = _deterministic_float_from_hash(track.trackhash[::-1])
|
|
return (0.55 * bitrate_score) + (0.25 * recency_score) + (0.20 * variety)
|
|
|
|
def final_score(track: Track) -> float:
|
|
base = base_score(track)
|
|
|
|
if max_play_count <= 0:
|
|
return base
|
|
|
|
user_signal = play_counts.get(track.trackhash, 0) / max_play_count
|
|
return (0.65 * user_signal) + (0.35 * base)
|
|
|
|
return sorted(tracks, key=final_score, reverse=True)
|
|
|
|
|
|
def _dedupe_tracks(tracks: list[Track]) -> list[Track]:
|
|
seen = set()
|
|
deduped: list[Track] = []
|
|
|
|
for track in tracks:
|
|
if track.trackhash in seen:
|
|
continue
|
|
|
|
seen.add(track.trackhash)
|
|
deduped.append(track)
|
|
|
|
return deduped
|
|
|
|
|
|
def build_artist_recommendations(
|
|
artisthash: str, userid: int
|
|
) -> dict[str, list[Track]]:
|
|
source_tracks = TrackStore.get_tracks_by_artisthash(artisthash)
|
|
source_tracks = _dedupe_tracks(source_tracks)
|
|
|
|
this_is_tracks = rank_tracks_for_user(source_tracks, userid)[:40]
|
|
|
|
radio_candidates: list[Track] = []
|
|
|
|
similar = SimilarArtistTable.get_by_hash(artisthash)
|
|
if similar:
|
|
for similar_hash in similar.get_artist_hash_set():
|
|
if similar_hash == artisthash:
|
|
continue
|
|
|
|
candidate_tracks = TrackStore.get_tracks_by_artisthash(similar_hash)
|
|
candidate_tracks = rank_tracks_for_user(
|
|
_dedupe_tracks(candidate_tracks), userid
|
|
)
|
|
radio_candidates.extend(candidate_tracks[:6])
|
|
|
|
if not radio_candidates:
|
|
fallback = TrackStore.get_flat_list()
|
|
fallback = [track for track in fallback if artisthash not in track.artisthashes]
|
|
fallback = rank_tracks_for_user(_dedupe_tracks(fallback), userid)
|
|
radio_candidates = fallback[:90]
|
|
|
|
radio_tracks = rank_tracks_for_user(_dedupe_tracks(radio_candidates), userid)[:50]
|
|
|
|
return {
|
|
"this_is": this_is_tracks,
|
|
"artist_radio": radio_tracks,
|
|
}
|