alembic/app/services/playlist_service.py

import json
import subprocess
import time

from sqlalchemy import select
from sqlalchemy.orm import Session

from app.models import Playlist
from app.settings import settings


def cron_to_time(cron_expr: str | None) -> str:
    """'30 1 * * *' -> '01:30'. Every playlist schedule today is a simple
    daily HH:MM (no day-of-week/day-of-month complexity -- that's only used
    by a couple of maintenance jobs), so the UI can offer a plain time
    picker instead of raw cron syntax. Returns '' for anything else
    (unscheduled, or a cron expression more complex than daily-at-HH:MM)."""
    if not cron_expr:
        return ""
    parts = cron_expr.split()
    if len(parts) == 5 and parts[2] == "*" and parts[3] == "*" and parts[4] == "*":
        try:
            hour, minute = int(parts[1]), int(parts[0])
            if 0 <= hour < 24 and 0 <= minute < 60:
                return f"{hour:02d}:{minute:02d}"
        except ValueError:
            pass
    return ""


def time_to_cron(time_str: str | None) -> str | None:
    """'01:30' -> '30 1 * * *'. Empty/invalid input means unscheduled."""
    if not time_str:
        return None
    try:
        hour_str, minute_str = time_str.split(":")
        hour, minute = int(hour_str), int(minute_str)
    except ValueError:
        return None
    if not (0 <= hour < 24 and 0 <= minute < 60):
        return None
    return f"{minute} {hour} * * *"

# The 17-entry array this project is migrating off of (was hardcoded in
# /opt/sldl/configs/regen.sh). Used once by seed_legacy() during Stage 1/2
# of the migration; the DB is the source of truth from then on. cron_expr
# values are the exact staggered slots from /etc/cron.d/sldl-maintenance,
# preserved so cutover doesn't change anyone's download schedule.
LEGACY_PLAYLISTS = {
    "digicore":  ("https://open.spotify.com/playlist/6tWHtPBECZTkZHPKFA3Fq4", "0 0 * * *", False),
    "techno":    ("https://open.spotify.com/playlist/5GlAkczmLWJFIJO4FvkLEZ", "0 1 * * *", False),
    "house":     ("https://open.spotify.com/playlist/2XF8ye6O5xqzT4NSfIXdfJ", "30 1 * * *", False),
    "lofi":      ("https://open.spotify.com/playlist/0qnyF6TAmuT3U6hFH2fiF1", "0 2 * * *", False),
    "y2k":       ("https://open.spotify.com/playlist/0iaA7ZJS00aRxhMwZn2GCU", "30 2 * * *", False),
    "weeb":      ("https://open.spotify.com/playlist/0599AbpsKRjsp2rlJI8jhf", "0 3 * * *", False),
    "shoegaze":  ("https://open.spotify.com/playlist/3R4S3tmbVKjXQ1RPAmryC5", "30 3 * * *", False),
    "bass":      ("https://open.spotify.com/playlist/2zkF4S16efaMmmzdIOe5w2", "0 4 * * *", False),
    "hiphop":    ("https://open.spotify.com/playlist/42JxTtOLJ7gG1ybfyy7Vmi", "30 4 * * *", False),
    "modular":   ("https://open.spotify.com/playlist/2kOfP2EM8dzdMYC6fXvlLb", "0 5 * * *", False),
    "hotdog":    ("https://open.spotify.com/playlist/53HrOL0qw47G9ywYZz3kgX", "30 5 * * *", False),
    "kpop":      ("https://open.spotify.com/playlist/31e2V512TIqr5JIfgkyseo", "0 6 * * *", False),
    "jungle":    ("https://open.spotify.com/playlist/4LjLeXg6ElneQiTaIcAHhE", "30 6 * * *", False),
    "goldenera": ("https://open.spotify.com/playlist/57vArhigysJfgwB6CY4VXR", "0 7 * * *", False),
    "botanica":  ("https://open.spotify.com/playlist/5KgQT9YWz3EqhIN4Jh69IU", "30 7 * * *", False),
    "hardcore":  ("https://open.spotify.com/playlist/1J1lbzlQKligzr2LWaq9Ex", "0 23 * * *", False),
    "liked":     ("https://open.spotify.com/playlist/4Z3qCYuU1sjNeNYO3Amzeo", "30 23 * * *", True),
}


def list_all(db: Session) -> list[Playlist]:
    return list(db.execute(select(Playlist).order_by(Playlist.name)).scalars())


def get(db: Session, playlist_id: int) -> Playlist | None:
    return db.get(Playlist, playlist_id)


def get_by_name(db: Session, name: str) -> Playlist | None:
    return db.execute(select(Playlist).where(Playlist.name == name)).scalar_one_or_none()


def create(
    db: Session,
    name: str,
    spotify_url: str,
    active: bool = True,
    no_m3u: bool = False,
    notes: str | None = None,
    cron_expr: str | None = None,
) -> Playlist:
    now = time.time()
    playlist = Playlist(
        name=name,
        spotify_url=spotify_url,
        active=active,
        no_m3u=no_m3u,
        notes=notes,
        cron_expr=cron_expr,
        created_at=now,
        updated_at=now,
    )
    db.add(playlist)
    db.commit()
    db.refresh(playlist)
    _sync_to_disk(db)
    return playlist


def update(db: Session, playlist_id: int, **fields) -> Playlist:
    playlist = db.get(Playlist, playlist_id)
    if playlist is None:
        raise ValueError(f"no playlist with id={playlist_id}")
    for key, value in fields.items():
        setattr(playlist, key, value)
    playlist.updated_at = time.time()
    db.commit()
    db.refresh(playlist)
    _sync_to_disk(db)
    return playlist


def delete(db: Session, playlist_id: int) -> None:
    """Remove the playlist from the DB and delete its rendered .conf file.
    Does NOT touch anything already downloaded/imported for it — that's a
    library decision, not a playlist-definition one."""
    playlist = db.get(Playlist, playlist_id)
    if playlist is None:
        return
    name = playlist.name
    db.delete(playlist)
    db.commit()
    conf_path = settings.pipeline_config_dir / f"{name}.conf"
    conf_path.unlink(missing_ok=True)
    _write_playlists_json(db)

    from app.services import scheduler_service

    scheduler = scheduler_service.get_scheduler()
    if scheduler is not None:
        scheduler_service.sync_playlist_jobs(scheduler)


def seed_legacy(db: Session) -> int:
    """One-time import of the legacy hardcoded array (migration Stage 1/2).
    Skips any name that already exists. Returns the number of rows created."""
    created = 0
    for name, (url, cron_expr, no_m3u) in LEGACY_PLAYLISTS.items():
        if get_by_name(db, name) is not None:
            continue
        create(db, name=name, spotify_url=url, no_m3u=no_m3u, cron_expr=cron_expr)
        created += 1
    return created


def _write_playlists_json(db: Session) -> None:
    """The file regen.sh reads. Every active-or-not playlist is included
    (see regen.sh's header comment) so a manual run is always possible;
    the scheduler is what actually skips inactive ones."""
    playlists = list_all(db)
    payload = [
        {
            "name": p.name,
            "spotify_url": p.spotify_url,
            "active": p.active,
            "no_m3u": p.no_m3u,
        }
        for p in playlists
    ]
    settings.pipeline_config_dir.mkdir(parents=True, exist_ok=True)
    out_path = settings.pipeline_config_dir / "playlists.json"
    out_path.write_text(json.dumps(payload, indent=2))


def regenerate_confs(db: Session) -> subprocess.CompletedProcess:
    """Write playlists.json, then run regen.sh to render/refresh every
    playlist's .conf file. Newly-created .conf files still have unpatched
    SOULSEEK_USER/SOULSEEK_PASS/SPOTIFY_CLIENT_ID/SPOTIFY_CLIENT_SECRET
    placeholders at this point -- _sync_to_disk() (this function's caller)
    re-renders credentials into them immediately afterward."""
    _write_playlists_json(db)
    regen_script = settings.pipeline_dir / "configs" / "regen.sh"
    return subprocess.run(
        [str(regen_script)],
        capture_output=True,
        text=True,
        env={
            "ALEMBIC_CONFIG_DIR": str(settings.alembic_config_dir),
            "MUSIC_DATA_DIR": str(settings.music_data_dir),
            "PIPELINE_DIR": str(settings.pipeline_dir),
            # Must include /opt/venv/bin: regen.sh shells out to `python3`
            # to parse playlists.json, and that's where this image's Python
            # actually lives (confirmed against the real container -- a
            # bare /usr/bin:/bin PATH made every regen.sh call silently
            # generate zero .conf files, no error surfaced to the caller).
            "PATH": "/opt/venv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
        },
    )


def _sync_to_disk(db: Session) -> None:
    """Convenience wrapper used by create()/update(): regenerate confs,
    immediately re-patch credentials into any newly-rendered file, and push
    the change to the live scheduler if one is running -- this is what
    makes add/remove-in-the-UI take effect without a redeploy."""
    regenerate_confs(db)
    # Imported lazily to avoid a circular import (credential_service and
    # scheduler_service don't depend on playlist_service, but importing at
    # module load time would still work here — done lazily anyway to keep
    # the dependency direction obvious as all three services grow).
    from app.services import credential_service, scheduler_service

    credential_service.render_scope(db, "soulseek")
    credential_service.render_scope(db, "spotify")

    scheduler = scheduler_service.get_scheduler()
    if scheduler is not None:
        scheduler_service.sync_playlist_jobs(scheduler)