haunt-fm/src/haunt_fm/api/playlists.py

from fastapi import APIRouter, Depends
from pydantic import BaseModel, Field
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from haunt_fm.db import get_session
from haunt_fm.models.track import PlaylistTrack, Track
from haunt_fm.services.music_assistant import play_playlist_on_speaker
from haunt_fm.services.playlist_generator import generate_playlist

router = APIRouter(prefix="/api/playlists")


class GenerateRequest(BaseModel):
    total_tracks: int = 20
    known_pct: int = 30
    name: str | None = None
    speaker_entity: str | None = None
    auto_play: bool = False
    vibe: str | None = None
    alpha: float = Field(default=0.5, ge=0.0, le=1.0)


@router.post("/generate")
async def generate(req: GenerateRequest, session: AsyncSession = Depends(get_session)):
    # Compute text embedding for vibe description
    vibe_embedding = None
    if req.vibe:
        from haunt_fm.services.embedding import embed_text, is_model_loaded, load_model

        if not is_model_loaded():
            load_model()
        vibe_embedding = embed_text(req.vibe)
    # Force pure taste when no vibe provided (preserves current behavior)
    alpha = req.alpha if req.vibe else 1.0

    playlist = await generate_playlist(
        session,
        total_tracks=req.total_tracks,
        known_pct=req.known_pct,
        name=req.name,
        vibe_embedding=vibe_embedding,
        alpha=alpha,
        vibe_text=req.vibe,
    )

    # Load playlist tracks with track info
    result = await session.execute(
        select(PlaylistTrack, Track)
        .join(Track, PlaylistTrack.track_id == Track.id)
        .where(PlaylistTrack.playlist_id == playlist.id)
        .order_by(PlaylistTrack.position)
    )
    rows = result.all()

    track_list = [
        {
            "position": pt.position,
            "artist": t.artist,
            "title": t.title,
            "album": t.album,
            "is_known": pt.is_known,
            "similarity_score": pt.similarity_score,
        }
        for pt, t in rows
    ]

    # Auto-play if requested
    if req.auto_play and req.speaker_entity:
        await play_playlist_on_speaker(track_list, req.speaker_entity)

    return {
        "playlist_id": playlist.id,
        "name": playlist.name,
        "total_tracks": playlist.total_tracks,
        "known_pct": playlist.known_pct,
        "vibe": playlist.vibe,
        "alpha": playlist.alpha,
        "tracks": track_list,
        "auto_played": req.auto_play and req.speaker_entity is not None,
    }