Files
vynl/backend/app/api/endpoints/playlist_fix.py
root 47ab3dd847 Add Fix My Playlist feature
New endpoint POST /api/playlists/{id}/fix that analyzes a playlist
using Claude AI to identify outlier tracks that don't match the
overall vibe, and suggests better-fitting replacements.

Frontend shows results with warm amber cards for outliers and green
cards for replacements, with dismissible suggestions and visual
highlighting of flagged tracks in the track list.
2026-03-31 08:43:20 -05:00

133 lines
3.8 KiB
Python

import json
import anthropic
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from app.core.config import settings
from app.core.database import get_db
from app.core.security import get_current_user
from app.models.playlist import Playlist
from app.models.track import Track
from app.models.user import User
from app.services.recommender import build_taste_profile
router = APIRouter(prefix="/playlists", tags=["playlists"])
class PlaylistFixRequest(BaseModel):
count: int = 5
class OutlierTrack(BaseModel):
track_number: int
artist: str
title: str
reason: str
class ReplacementTrack(BaseModel):
title: str
artist: str
album: str | None = None
reason: str
class PlaylistFixResponse(BaseModel):
playlist_vibe: str
outliers: list[OutlierTrack]
replacements: list[ReplacementTrack]
@router.post("/{playlist_id}/fix", response_model=PlaylistFixResponse)
async def fix_playlist(
playlist_id: int,
data: PlaylistFixRequest = PlaylistFixRequest(),
user: User = Depends(get_current_user),
db: AsyncSession = Depends(get_db),
):
# Load playlist
result = await db.execute(
select(Playlist).where(Playlist.id == playlist_id, Playlist.user_id == user.id)
)
playlist = result.scalar_one_or_none()
if not playlist:
raise HTTPException(status_code=404, detail="Playlist not found")
# Load tracks
result = await db.execute(
select(Track).where(Track.playlist_id == playlist.id)
)
tracks = list(result.scalars().all())
if not tracks:
raise HTTPException(status_code=400, detail="Playlist has no tracks")
# Build taste profile
taste_profile = build_taste_profile(tracks)
# Build numbered track list
track_list = "\n".join(
f"{i + 1}. {t.artist} - {t.title}" for i, t in enumerate(tracks)
)
count = min(max(data.count, 1), 10)
prompt = f"""You are Vynl, a music playlist curator. Analyze this playlist and identify tracks that don't fit the overall vibe.
Playlist: {playlist.name}
Taste profile: {json.dumps(taste_profile, indent=2)}
Tracks:
{track_list}
Analyze the playlist and respond with a JSON object:
{{
"playlist_vibe": "A 1-2 sentence description of the overall playlist vibe/mood",
"outliers": [
{{
"track_number": 1,
"artist": "...",
"title": "...",
"reason": "Why this track doesn't fit the playlist vibe"
}}
],
"replacements": [
{{
"title": "...",
"artist": "...",
"album": "...",
"reason": "Why this fits better"
}}
]
}}
Identify up to {count} outlier tracks. For each outlier, suggest a replacement that fits the playlist vibe better. Focus on maintaining sonic cohesion — same energy, tempo range, and mood.
Return ONLY the JSON object."""
# Call Claude API
client = anthropic.Anthropic(api_key=settings.ANTHROPIC_API_KEY)
message = client.messages.create(
model="claude-haiku-4-5-20251001",
max_tokens=2000,
messages=[{"role": "user", "content": prompt}],
)
response_text = message.content[0].text.strip()
# Handle potential markdown code blocks
if response_text.startswith("```"):
response_text = response_text.split("\n", 1)[1]
response_text = response_text.rsplit("```", 1)[0]
try:
fix_data = json.loads(response_text)
except json.JSONDecodeError:
raise HTTPException(status_code=500, detail="Failed to parse AI response")
return PlaylistFixResponse(
playlist_vibe=fix_data.get("playlist_vibe", ""),
outliers=[OutlierTrack(**o) for o in fix_data.get("outliers", [])],
replacements=[ReplacementTrack(**r) for r in fix_data.get("replacements", [])],
)