refactor(catalog): the HTTP layer reads through queries and writes through the service

Channels, search and sync do no database work in their routes any more: reads go through
catalog/queries, writes through catalog/service, and a live search's ingest is catalog/search.
What a catalog route needs from Reader (a playlist's channels, a user's tag links, the feed
projection of results) it asks reader/queries and reader/service. The scheduler and the runs page
read channel titles and the work queue through catalog/queries. Catalog is fenced below its HTTP
layer: its owner filters go through userscope, it reads no other unit's tables, and its ingest
jobs commit only where they are named.

backend/app/catalog/queries.py

@@ -0,0 +1,296 @@
+"""Catalog's reads: channels and videos, and each user's footprint in them (subscriptions, blocks,
+explorations), for the HTTP layer and for the core code that asks about them.
+
+A user's row is read through `userscope`, so someone else's is the same answer as a missing one.
+Catalog does not read another unit's tables: what it needs from Reader (a playlist's channels, a
+user's tag links) it asks `reader.queries`.
+"""
+
+from datetime import datetime
+
+from sqlalchemy import Select, and_, case, func, or_, select
+from sqlalchemy.orm import Session
+
+from app.catalog.models import (
+    LIVE_OR_UPCOMING,
+    BlockedChannel,
+    Channel,
+    ExploredChannel,
+    Subscription,
+    Video,
+)
+from app.collation import collated
+from app.models import User
+from app.sync.explore import followed_channel
+from app.userscope import owned_by
+
+# --- channels --------------------------------------------------------------------------------
+
+
+def channel(db: Session, channel_id: str) -> Channel | None:
+    return db.get(Channel, channel_id)
+
+
+def channel_title(db: Session, channel_id: str) -> str | None:
+    return db.scalar(select(Channel.title).where(Channel.id == channel_id))
+
+
+def channel_titles(db: Session, ids: set[str]) -> dict[str, str]:
+    """Each channel's title by id; a channel with no title yet is left out."""
+    if not ids:
+        return {}
+    rows = db.execute(select(Channel.id, Channel.title).where(Channel.id.in_(ids)))
+    return {cid: title for cid, title in rows.tuples() if title is not None}
+
+
+def channel_aggregates(channel_ids: list[str]) -> Select:
+    """Per-channel stored count, last upload and total duration, in one grouped pass. Every column it
+    reads is in `ix_videos_channel_pub_cover` (migration 0095), so Postgres answers it from the index
+    alone; a test holds that (test_channel_list_index_only)."""
+    return (
+        select(
+            Video.channel_id,
+            func.count(Video.id),
+            func.max(Video.published_at),
+            func.coalesce(func.sum(Video.duration_seconds), 0),
+        )
+        .where(Video.channel_id.in_(channel_ids))
+        .group_by(Video.channel_id)
+    )
+
+
+def aggregates(db: Session, channel_ids: list[str]) -> list[tuple[str, int, datetime | None, int]]:
+    """`channel_aggregates`, run: (channel id, stored videos, last upload, total seconds)."""
+    if not channel_ids:
+        return []
+    return list(db.execute(channel_aggregates(channel_ids)).tuples())
+
+
+def video_counts(db: Session, channel_id: str) -> tuple[int, int, int]:
+    """A channel's stored videos, its Shorts and its live/upcoming ones, in one grouped pass."""
+    n_all, n_short, n_live = db.execute(
+        select(
+            func.count(Video.id),
+            func.count(Video.id).filter(Video.is_short.is_(True)),
+            func.count(Video.id).filter(Video.live_status.in_(LIVE_OR_UPCOMING)),
+        ).where(Video.channel_id == channel_id)
+    ).one()
+    return int(n_all or 0), int(n_short or 0), int(n_live or 0)
+
+
+def deep_queued(db: Session, channel_ids: list[str]) -> set[str]:
+    """Which of these channels at least one user (any user) has asked full history for."""
+    if not channel_ids:
+        return set()
+    return set(
+        db.execute(
+            select(Subscription.channel_id)
+            .where(
+                Subscription.channel_id.in_(channel_ids),
+                Subscription.deep_requested.is_(True),
+            )
+            .distinct()
+        ).scalars()
+    )
+
+
+def followed(db: Session, channel_id: str) -> bool:
+    """Whether anyone subscribes to the channel."""
+    return (
+        db.execute(
+            select(Subscription.id).where(Subscription.channel_id == channel_id).limit(1)
+        ).first()
+        is not None
+    )
+
+
+# --- a user's subscriptions, blocks and explorations ----------------------------------------
+
+
+def subscriptions(db: Session, user: User, lang: str) -> list[tuple[Subscription, Channel]]:
+    """The user's subscriptions with their channels, highest priority first, then by title in the
+    reader's alphabet."""
+    return list(
+        db.execute(
+            select(Subscription, Channel)
+            .join(Channel, Channel.id == Subscription.channel_id)
+            .where(owned_by(Subscription.user_id, user))
+            .order_by(Subscription.priority.desc(), collated(Channel.title, lang))
+        ).tuples()
+    )
+
+
+def subscription(db: Session, user: User, channel_id: str) -> Subscription | None:
+    return db.execute(
+        select(Subscription).where(
+            owned_by(Subscription.user_id, user), Subscription.channel_id == channel_id
+        )
+    ).scalar_one_or_none()
+
+
+def subscribed_channels(user: User):
+    """The channel ids the user subscribes to, as a subquery."""
+    return select(Subscription.channel_id).where(owned_by(Subscription.user_id, user))
+
+
+def exploration(db: Session, user: User, channel_id: str) -> ExploredChannel | None:
+    return db.execute(
+        select(ExploredChannel).where(
+            owned_by(ExploredChannel.user_id, user), ExploredChannel.channel_id == channel_id
+        )
+    ).scalar_one_or_none()
+
+
+def is_blocked(db: Session, user: User, channel_id: str) -> bool:
+    return (
+        db.execute(
+            select(BlockedChannel.id).where(
+                owned_by(BlockedChannel.user_id, user), BlockedChannel.channel_id == channel_id
+            )
+        ).first()
+        is not None
+    )
+
+
+def blocked_ids(db: Session, user: User) -> set[str]:
+    return set(
+        db.scalars(select(BlockedChannel.channel_id).where(owned_by(BlockedChannel.user_id, user)))
+    )
+
+
+def blocked_channels(db: Session, user: User, lang: str) -> list[Channel]:
+    return list(
+        db.execute(
+            select(Channel)
+            .join(BlockedChannel, BlockedChannel.channel_id == Channel.id)
+            .where(owned_by(BlockedChannel.user_id, user))
+            .order_by(collated(Channel.title, lang))
+        ).scalars()
+    )
+
+
+# --- sync progress ---------------------------------------------------------------------------
+
+
+def catalog_totals(db: Session, user: User) -> dict:
+    """The instance's catalog size and this user's subscription count (the sync status card)."""
+    return {
+        "subscriptions": db.scalar(
+            select(func.count())
+            .select_from(Subscription)
+            .where(owned_by(Subscription.user_id, user))
+        ),
+        "channels_total": db.scalar(select(func.count()).select_from(Channel)),
+        "channels_backfilling": db.scalar(
+            select(func.count()).select_from(Channel).where(Channel.backfill_done.is_(False))
+        ),
+        "videos_total": db.scalar(select(func.count()).select_from(Video)),
+        "pending_enrich": db.scalar(
+            select(func.count()).select_from(Video).where(Video.enriched_at.is_(None))
+        ),
+    }
+
+
+def my_progress(db: Session, user: User) -> tuple[int, int, int, int]:
+    """Over the channels this user subscribes to: how many, how many have details, how many their
+    recent uploads, how many their whole history."""
+    total, details_synced, recent_synced, all_deep_done = db.execute(
+        select(
+            func.count(Channel.id),
+            func.count(Channel.details_synced_at),
+            func.count(Channel.recent_synced_at),
+            func.sum(case((Channel.backfill_done.is_(True), 1), else_=0)),
+        )
+        .select_from(Channel)
+        .join(
+            Subscription,
+            and_(Subscription.channel_id == Channel.id, owned_by(Subscription.user_id, user)),
+        )
+    ).one()
+    return total or 0, details_synced or 0, recent_synced or 0, int(all_deep_done or 0)
+
+
+def my_deep_requested(db: Session, user: User) -> list[Channel]:
+    """The channels this user asked full history for."""
+    return list(
+        db.execute(
+            select(Channel).join(
+                Subscription,
+                and_(
+                    Subscription.channel_id == Channel.id,
+                    owned_by(Subscription.user_id, user),
+                    Subscription.deep_requested.is_(True),
+                ),
+            )
+        ).scalars()
+    )
+
+
+def my_video_count(db: Session, user: User) -> int:
+    """The videos of the channels this user subscribes to and has not hidden."""
+    return (
+        db.scalar(
+            select(func.count(Video.id)).join(
+                Subscription,
+                and_(
+                    Subscription.channel_id == Video.channel_id,
+                    owned_by(Subscription.user_id, user),
+                    Subscription.hidden.is_(False),
+                ),
+            )
+        )
+        or 0
+    )
+
+
+def video_total(db: Session) -> int:
+    return db.scalar(select(func.count(Video.id))) or 0
+
+
+def deep_backlog(db: Session) -> list[Channel]:
+    """Every channel someone asked full history for that does not have it yet."""
+    deep_requested = (
+        select(Subscription.id)
+        .where(Subscription.channel_id == Channel.id, Subscription.deep_requested.is_(True))
+        .exists()
+    )
+    return list(
+        db.execute(
+            select(Channel).where(Channel.backfill_done.is_(False), deep_requested)
+        ).scalars()
+    )
+
+
+def work_queue(db: Session) -> dict:
+    """What the catalog's jobs still have queued, instance-wide (the scheduler card)."""
+    return {
+        # The same selection run_recent_backfill works through, or the card counts channels the
+        # job will never touch and never reaches zero.
+        "channels_recent_pending": db.scalar(
+            select(func.count())
+            .select_from(Channel)
+            .where(Channel.recent_synced_at.is_(None), followed_channel())
+        )
+        or 0,
+        "videos_pending_enrich": db.scalar(
+            select(func.count()).select_from(Video).where(Video.enriched_at.is_(None))
+        )
+        or 0,
+        "videos_pending_shorts": db.scalar(
+            select(func.count())
+            .select_from(Video)
+            .where(Video.shorts_probed.is_(False), Video.enriched_at.is_not(None))
+        )
+        or 0,
+        "videos_live_refresh": db.scalar(
+            select(func.count())
+            .select_from(Video)
+            .where(
+                or_(
+                    Video.live_status.in_(("live", "upcoming")),
+                    and_(Video.live_status == "was_live", Video.duration_seconds.is_(None)),
+                )
+            )
+        )
+        or 0,
+    }

backend/app/catalog/search.py

@@ -0,0 +1,232 @@
+"""Live YouTube search, the catalog's side: what a page of results leaves in the shared catalog.
+
+A result becomes a catalog row so it renders with the normal feed cards and the in-app player and
+gains per-user state. The ingest runs in steps with a YouTube call between each, and each step's
+rows are committed before the next call: an enrich that fails rolls back to the stubs, which stay
+(the FK targets for what follows, backfilled later). Results are flagged (`videos.via_search`,
+`channels.from_search`) so the Library can hide this search-discovered noise; Shorts and
+live/upcoming videos are never kept. The HTTP layer (`routes/search.py`) runs the paging, the caps
+and the refusals.
+"""
+
+from collections.abc import Sequence
+from concurrent.futures import ThreadPoolExecutor
+from datetime import datetime, timezone
+
+from sqlalchemy import delete, func, select, update
+from sqlalchemy.dialects.postgresql import insert as pg_insert
+from sqlalchemy.engine import CursorResult
+from sqlalchemy.orm import Session
+
+from app import logs, quota, sysconfig
+from app.catalog import queries
+from app.catalog.models import LIVE_OR_UPCOMING, Channel, SearchFind, Subscription, Video
+from app.models import User
+from app.reader import queries as reader_queries
+from app.sync.subscriptions import apply_channel_details
+from app.sync.videos import apply_video_details, insert_stubs, parse_dt
+from app.userscope import owned_by
+from app.utils import like_escape
+from app.youtube.client import YouTubeClient, YouTubeError
+from app.youtube.shorts import make_client, probe_is_short
+
+log = logs.get_logger(__name__)
+
+
+def classify_shorts(db: Session, videos: Sequence[Video]) -> None:
+    """Confirm/deny Shorts for the freshly-ingested videos so none slip into the feed.
+
+    Mirrors the scheduler's run_shorts_classification, but scoped to just these rows and run
+    synchronously (the search is an explicit, awaited action). Non-candidates (too long, no
+    duration, or live) are finalised without a probe; the rest hit youtube.com/shorts (no
+    quota). Undetermined probes are left for the scheduler to retry."""
+    probe_max = sysconfig.get_int(db, "shorts_probe_max_seconds")
+    to_probe: list[Video] = []
+    for v in videos:
+        if v.shorts_probed:
+            continue
+        if v.enriched_at is None:
+            # Enrichment failed (proxy blip) or YouTube omitted the row — duration is unknown,
+            # so DON'T finalise shorts_probed off a null duration; leave it for the scheduler
+            # (which only classifies enriched rows) to retry. Otherwise a real Short would leak.
+            continue
+        if v.live_status != "none" or v.duration_seconds is None or v.duration_seconds > probe_max:
+            v.is_short = False
+            v.shorts_probed = True
+        else:
+            to_probe.append(v)
+    if to_probe:
+        with make_client() as client:
+
+            def work(v: Video):
+                return v, probe_is_short(client, v.id)
+
+            with ThreadPoolExecutor(max_workers=16) as pool:
+                for v, result in pool.map(work, to_probe):
+                    if result is None:
+                        continue
+                    v.is_short = result
+                    v.shorts_probed = True
+    db.commit()
+
+
+def ingest_candidates(
+    db: Session, yt: YouTubeClient, user: User, candidates: list[dict]
+) -> list[str]:
+    """Materialise one page of search candidates into the catalog (channel stubs + enrich,
+    video stubs flagged via_search, enrich, Shorts classification) and return the KEEPABLE
+    video ids — non-Short, non-live — in the input relevance order."""
+    ids = [it["id"] for it in candidates]
+    if not ids:
+        return []
+
+    # 1) Channels are the FK target — create stubs for unknown ones (flagged from_search),
+    #    then enrich the new ones (channels.list, 1 unit). Stubs survive an enrich failure.
+    channel_ids = list({it["channel_id"] for it in candidates})
+    existing = set(db.scalars(select(Channel.id).where(Channel.id.in_(channel_ids))).all())
+    new_channel_ids = [c for c in channel_ids if c not in existing]
+    if new_channel_ids:
+        titles = {it["channel_id"]: it["channel_title"] for it in candidates}
+        for cid in new_channel_ids:
+            db.add(Channel(id=cid, title=titles.get(cid), from_search=True))
+        db.commit()
+        try:
+            with quota.attribute(user.id, quota.QuotaAction.CHANNELS_DISCOVER):
+                details = yt.get_channels(new_channel_ids)
+            apply_channel_details(db, details, new_channel_ids)
+            db.commit()
+        except YouTubeError:
+            # The stubs remain and the details can be backfilled later — but until they are, those
+            # channels sit in the results with no thumbnail and no subscriber count, looking like
+            # channels that have neither.
+            log.warning(
+                "the channels found by a search could not be enriched",
+                extra=logs.event("search.channel_enrich_failed", channels=len(new_channel_ids)),
+            )
+            db.rollback()  # details can be backfilled later; the stubs remain
+
+    # 2) Video stubs, flagged via_search. Existing rows keep their flags (ON CONFLICT DO
+    #    NOTHING), so an organically-synced video stays organic.
+    #    published_at is NOT NULL (migration 0068); the scrape source exposes no publish date
+    #    (only a relative "3 years ago"), so fall back to now() to satisfy the constraint — the
+    #    enrich in step 3 overwrites it with the video's real snippet date.
+    now = datetime.now(timezone.utc)
+    insert_stubs(
+        db,
+        [
+            {
+                "id": it["id"],
+                "channel_id": it["channel_id"],
+                "title": it["title"],
+                "published_at": parse_dt(it["published_at"]) or now,
+                "thumbnail_url": it["thumbnail_url"],
+                "via_search": True,
+            }
+            for it in candidates
+        ],
+    )
+
+    # 3) Enrich (videos.list, 1 unit/50) so cards have duration/stats and we can judge live.
+    videos = db.scalars(select(Video).where(Video.id.in_(ids))).all()
+    try:
+        with quota.attribute(user.id, quota.QuotaAction.VIDEOS_ENRICH):
+            detail_by_id = {it["id"]: it for it in yt.get_videos(ids)}
+    except YouTubeError:
+        # Every candidate then stays unenriched, and an unenriched video cannot be judged live or
+        # Short — so it is dropped. A working search returns nothing and reads as "no results".
+        log.warning(
+            "the videos found by a search could not be enriched",
+            extra=logs.event("search.video_enrich_failed", candidates=len(ids)),
+        )
+        detail_by_id = {}
+    enriched_at = datetime.now(
+        timezone.utc
+    )  # when THIS enrich ran (distinct from the stub placeholder)
+    for v in videos:
+        item = detail_by_id.get(v.id)
+        if item is None:
+            continue
+        apply_video_details(v, item)
+        v.enriched_at = enriched_at
+    db.commit()
+
+    # 4) Confirm/deny Shorts (no quota) so none enter via search.
+    classify_shorts(db, videos)
+
+    keep = {
+        v.id
+        for v in videos
+        if v.enriched_at is not None and not v.is_short and v.live_status not in LIVE_OR_UPCOMING
+    }
+    return [vid for vid in ids if vid in keep]
+
+
+def _fold_term(db: Session, video_ids: list[str], term: str) -> None:
+    """Append `term` to each video's space-joined `search_terms`, unless it is already one of them.
+
+    "Already one of them" is a whole-term match, as a literal: a substring test skipped `cat` on a
+    video already found for `category`, and an unescaped one read the `_` in `my_channel` as a
+    wildcard — either way the term was never folded in, and local search lost that relevance."""
+    padded = func.concat(" ", func.coalesce(Video.search_terms, ""), " ")
+    db.execute(
+        update(Video)
+        .where(Video.id.in_(video_ids))
+        .where(padded.notilike(f"% {like_escape(term)} %"))
+        .values(
+            search_terms=func.trim(
+                func.coalesce(Video.search_terms, "").op("||")(" ").op("||")(term)
+            )
+        )
+    )
+
+
+def new_first(db: Session, user: User, ids: list[str]) -> list[str]:
+    """Reorder results so genuinely-new discoveries come first and things the user already has
+    (a subscribed channel, or a video they've watched / in-progress / saved / playlisted) sink
+    to the back — keeping the relevance order within each group."""
+    if not ids:
+        return ids
+    have = set(
+        db.scalars(
+            select(Video.id).where(
+                Video.id.in_(ids), Video.channel_id.in_(queries.subscribed_channels(user))
+            )
+        )
+    ) | reader_queries.held_by(db, user, ids)
+    return [i for i in ids if i not in have] + [i for i in ids if i in have]
+
+
+def record_finds(db: Session, user: User, video_ids: list[str], term: str) -> None:
+    """These results as THIS user's search finds (the Mine feed, the Source filter), and the term
+    folded into each one's `search_terms` so local full-text search inherits YouTube's relevance.
+    Idempotent."""
+    db.execute(
+        pg_insert(SearchFind)
+        .values([{"user_id": user.id, "video_id": vid} for vid in video_ids])
+        .on_conflict_do_nothing(index_elements=["user_id", "video_id"])
+    )
+    _fold_term(db, video_ids, term)
+
+
+def clear(db: Session, user: User, video_ids: list[str]) -> int:
+    """Discard these results "as if never added": drop this user's finds of them, then delete the
+    ones nobody kept — a `via_search` video no reader holds (`reader.queries.kept_by_a_reader`),
+    whose channel nobody subscribes to, and that no other user still has as a find. Returns how
+    many videos went."""
+    db.execute(
+        delete(SearchFind).where(
+            owned_by(SearchFind.user_id, user), SearchFind.video_id.in_(video_ids)
+        )
+    )
+    subscribed = select(Subscription.id).where(Subscription.channel_id == Video.channel_id).exists()
+    other_find = select(SearchFind.id).where(SearchFind.video_id == Video.id).exists()
+    result = db.execute(
+        delete(Video).where(
+            Video.id.in_(video_ids),
+            Video.via_search.is_(True),
+            ~reader_queries.kept_by_a_reader(Video.id),
+            ~subscribed,
+            ~other_find,
+        )
+    )
+    return result.rowcount if isinstance(result, CursorResult) else 0

backend/app/catalog/service.py

@@ -0,0 +1,133 @@
+"""Catalog's writes a request makes: a user's subscription settings, what they explore or block, a
+subscription recorded or dropped, a channel's sync markers reset.
+
+Every function here flushes and leaves the commit to its caller (the handler). The YouTube side of a
+subscribe or an unsubscribe is the handler's (it needs the user's client and its refusals); what
+lands here is the local record of it. The ingest jobs (`sync/`, `catalog/search`) write the
+catalog's shared rows themselves.
+"""
+
+from datetime import datetime, timezone
+
+from sqlalchemy import delete, update
+from sqlalchemy.engine import CursorResult
+from sqlalchemy.orm import Session
+
+from app.catalog import queries
+from app.catalog.models import BlockedChannel, Channel, ExploredChannel, Subscription, Video
+from app.models import User
+from app.userscope import owned_by
+
+
+def remember_own_channel(user: User, channel_id: str) -> None:
+    """The user's own YouTube channel, so discovery never offers it to them."""
+    user.yt_channel_id = channel_id
+
+
+def update_subscription(
+    db: Session,
+    sub: Subscription,
+    *,
+    priority: int | None = None,
+    hidden: bool | None = None,
+    deep_requested: bool | None = None,
+) -> bool:
+    """Change the settings given (None leaves one as it is). Returns whether full history was just
+    turned ON — the caller then pulls the channel now rather than at the scheduler's next tick."""
+    turned_on = False
+    if priority is not None:
+        sub.priority = priority
+    if hidden is not None:
+        sub.hidden = hidden
+    if deep_requested is not None:
+        # Turning it off won't undo already-fetched videos; it stops further deep paging if nobody
+        # else still wants it.
+        turned_on = deep_requested and not sub.deep_requested
+        sub.deep_requested = deep_requested
+    db.flush()
+    return turned_on
+
+
+def set_deep_all(db: Session, user: User, on: bool) -> int:
+    """Every one of the user's channels in (or out of) full-history backfill; how many rows moved."""
+    result = db.execute(
+        update(Subscription).where(owned_by(Subscription.user_id, user)).values(deep_requested=on)
+    )
+    return result.rowcount if isinstance(result, CursorResult) else 0
+
+
+def explore(db: Session, user: User, channel: Channel) -> None:
+    """Record (or refresh the grace clock of) the user's exploration of a channel, and flag the
+    channel ephemeral unless someone follows it — the cleanup job's keep rule reads both."""
+    existing = queries.exploration(db, user, channel.id)
+    if existing is None:
+        db.add(ExploredChannel(user_id=user.id, channel_id=channel.id))
+    else:
+        existing.created_at = datetime.now(timezone.utc)
+    if not channel.from_explore and not queries.followed(db, channel.id):
+        channel.from_explore = True
+    db.flush()
+
+
+def reset_backfill(db: Session, channel: Channel) -> None:
+    """Fetch the channel again from scratch: its backfill markers cleared, and full history asked
+    for on EVERY subscription to it — the deep scheduler gates on an EXISTS over those, so the admin
+    who resets it need not subscribe themselves."""
+    channel.backfill_done = False
+    channel.backfill_cursor = None
+    channel.recent_synced_at = None
+    db.execute(
+        update(Subscription)
+        .where(Subscription.channel_id == channel.id)
+        .values(deep_requested=True)
+    )
+    db.flush()
+
+
+def record_subscription(db: Session, user: User, channel: Channel, yt_subscription_id: str) -> None:
+    """The subscription YouTube now holds, recorded here. Subscribing is the "keep" signal: an
+    explored channel becomes an organic one, so the cleanup job leaves it alone and its videos join
+    the shared Library like any subscribed channel's uploads."""
+    db.add(
+        Subscription(
+            user_id=user.id,
+            channel_id=channel.id,
+            yt_subscription_id=yt_subscription_id or None,
+            subscribed_at=datetime.now(timezone.utc),
+        )
+    )
+    if channel.from_explore:
+        channel.from_explore = False
+        db.execute(
+            update(Video)
+            .where(Video.channel_id == channel.id, Video.via_explore.is_(True))
+            .values(via_explore=False)
+        )
+    db.flush()
+
+
+def drop_subscription(db: Session, sub: Subscription) -> None:
+    db.delete(sub)
+    db.flush()
+
+
+def block(db: Session, user: User, channel_id: str) -> None:
+    """Block a channel for this user (idempotent), and end any exploration of it so the cleanup job
+    can reclaim it."""
+    if queries.is_blocked(db, user, channel_id):
+        return
+    db.add(BlockedChannel(user_id=user.id, channel_id=channel_id))
+    db.execute(
+        delete(ExploredChannel).where(
+            owned_by(ExploredChannel.user_id, user), ExploredChannel.channel_id == channel_id
+        )
+    )
+    db.flush()
+
+
+def unblock(db: Session, user: User, channel_id: str) -> None:
+    db.execute(
+        delete(BlockedChannel).where(
+            owned_by(BlockedChannel.user_id, user), BlockedChannel.channel_id == channel_id
+        )
+    )

backend/app/reader/queries.py

@@ -10,9 +10,10 @@ than joining Reader's tables itself.
 from sqlalchemy import ColumnElement, and_, func, or_, select
 from sqlalchemy.orm import InstrumentedAttribute, Session, aliased
 
-from app.feedquery import feed_columns
+from app.collation import collated
+from app.feedquery import feed_columns, serialize
 from app.models import User
-from app.catalog.models import Channel, Video
+from app.catalog.models import Channel, Subscription, Video
 from app.reader.models import ChannelTag, Playlist, PlaylistItem, SavedView, Tag, VideoState
 from app.userscope import owned_by, owned_row
 
@@ -269,3 +270,92 @@ def tags_in_feed_views(db: Session) -> set[int]:
         for (filters,) in db.execute(select(SavedView.filters).where(SavedView.source == "feed"))
         for t in view_tag_ids(filters)
     }
+
+
+def held_by(db: Session, user: User, video_ids: list[str]) -> set[str]:
+    """Which of these videos the user already holds: watched, in progress or hidden, or in one of
+    their playlists (a live search sinks them below the new finds)."""
+    if not video_ids:
+        return set()
+    has_state = (
+        select(VideoState.id)
+        .where(VideoState.video_id == Video.id, owned_by(VideoState.user_id, user))
+        .exists()
+    )
+    in_playlist = (
+        select(PlaylistItem.id)
+        .join(Playlist, Playlist.id == PlaylistItem.playlist_id)
+        .where(PlaylistItem.video_id == Video.id, owned_by(Playlist.user_id, user))
+        .exists()
+    )
+    return set(
+        db.scalars(select(Video.id).where(Video.id.in_(video_ids), or_(has_state, in_playlist)))
+    )
+
+
+def feed_rows_by_ids(db: Session, user: User, video_ids: list[str]) -> list[dict]:
+    """These videos serialized with the feed's projection (their channel, this user's watch state,
+    saved), in the order given."""
+    if not video_ids:
+        return []
+    state = aliased(VideoState)
+    rows = db.execute(
+        select(*feed_columns(user, state))
+        .join(Channel, Channel.id == Video.channel_id)
+        .outerjoin(state, and_(state.video_id == Video.id, owned_by(state.user_id, user)))
+        .where(Video.id.in_(video_ids))
+    ).all()
+    by_id = {r.id: serialize(r) for r in rows}
+    return [by_id[i] for i in video_ids if i in by_id]
+
+
+def playlist_channels(db: Session, user: User, exclude: str | None, lang: str) -> list:
+    """The channels of the videos in the user's playlists that they don't subscribe to (`exclude`:
+    their own channel), each with how many of those videos it has and across how many playlists;
+    most present first, then by title in the reader's alphabet."""
+    subscribed = select(Subscription.channel_id).where(owned_by(Subscription.user_id, user))
+    q = (
+        select(
+            Channel,
+            func.count(func.distinct(PlaylistItem.video_id)),
+            func.count(func.distinct(Playlist.id)),
+        )
+        .select_from(PlaylistItem)
+        .join(Playlist, Playlist.id == PlaylistItem.playlist_id)
+        .join(Video, Video.id == PlaylistItem.video_id)
+        .join(Channel, Channel.id == Video.channel_id)
+        .where(owned_by(Playlist.user_id, user), Channel.id.not_in(subscribed))
+    )
+    if exclude:
+        q = q.where(Channel.id != exclude)
+    return list(
+        db.execute(
+            q.group_by(Channel.id).order_by(
+                func.count(func.distinct(PlaylistItem.video_id)).desc(),
+                collated(Channel.title, lang),
+            )
+        ).all()
+    )
+
+
+def user_tag_links(db: Session, user: User, channel_id: str | None = None) -> dict[str, list[int]]:
+    """The user's own tag links by channel (one channel's, when given)."""
+    stmt = select(ChannelTag.channel_id, ChannelTag.tag_id).where(
+        owned_by(ChannelTag.user_id, user)
+    )
+    if channel_id is not None:
+        stmt = stmt.where(ChannelTag.channel_id == channel_id)
+    out: dict[str, list[int]] = {}
+    for cid, tag_id in db.execute(stmt).tuples():
+        out.setdefault(cid, []).append(tag_id)
+    return out
+
+
+def user_tag_link(db: Session, user: User, channel_id: str, tag_id: int) -> ChannelTag | None:
+    return db.execute(
+        select(ChannelTag).where(
+            ChannelTag.channel_id == channel_id,
+            ChannelTag.tag_id == tag_id,
+            owned_by(ChannelTag.user_id, user),
+        )
+    ).scalar_one_or_none()

backend/app/reader/service.py

@@ -464,3 +464,17 @@ def reorder_items(db: Session, pl: Playlist, order: list[str]) -> int:
     touch(pl)
     db.flush()
     return pos
+
+
+def attach_user_tag(db: Session, user: User, channel_id: str, tag_id: int) -> None:
+    """The user's own label on a channel (idempotent). The caller has checked the tag is theirs."""
+    if queries.user_tag_link(db, user, channel_id, tag_id) is None:
+        db.add(ChannelTag(channel_id=channel_id, tag_id=tag_id, user_id=user.id, source="user"))
+        db.flush()
+
+
+def detach_user_tag(db: Session, user: User, channel_id: str, tag_id: int) -> None:
+    row = queries.user_tag_link(db, user, channel_id, tag_id)
+    if row is not None:
+        db.delete(row)
+        db.flush()

backend/app/routes/channels.py

@@ -4,28 +4,22 @@ hidden, tags) and per-channel sync state. Local reads/writes plus YouTube-side w
 
 from datetime import datetime, timezone
 from functools import partial
+from typing import TYPE_CHECKING
 
 from fastapi import APIRouter, Depends
 from pydantic import BaseModel
-from sqlalchemy import Select, func, select, update
 from sqlalchemy.orm import Session
 
-from app.collation import collated, sorted_words
+from app.collation import sorted_words
 from app.mailtext import lang_for_user
 from app import logs, quota, scheduler
 from app.auth import admin_user, current_user, require_write_scope
 from app.db import get_db
 from app.models import User
-from app.catalog.models import (
-    LIVE_OR_UPCOMING,
-    BlockedChannel,
-    Channel,
-    ExploredChannel,
-    Subscription,
-    Video,
-)
-from app.reader.models import ChannelTag, Playlist, PlaylistItem, Tag
-from app.routes._common import get_or_404, not_found, owned_or_404, youtube_refusal
+from app.catalog import queries, service
+from app.reader import queries as reader_queries
+from app.reader import service as reader_service
+from app.routes._common import not_found, youtube_refusal
 from app.sync.explore import explore_ingest_page
 from app.sync.runner import backfill_channel_now, run_recent_backfill
 from app.sync.subscriptions import apply_channel_details, details_stale
@@ -33,35 +27,17 @@ from app.utils import iso
 from app.youtube.client import YouTubeClient, YouTubeError
 from app.refusal import refused
 
+if TYPE_CHECKING:
+    from app.catalog.models import Channel, Subscription
+
 router = APIRouter(prefix="/api/channels", tags=["channels"])
 
 log = logs.get_logger(__name__)
 
 
-def channel_aggregates(channel_ids: list[str]) -> Select:
-    """Per-channel stored count, last upload and total duration, in one grouped pass. Every column it
-    reads is in `ix_videos_channel_pub_cover` (migration 0095), so Postgres answers it from the index
-    alone; a test holds that (test_channel_list_index_only)."""
-    return (
-        select(
-            Video.channel_id,
-            func.count(Video.id),
-            func.max(Video.published_at),
-            func.coalesce(func.sum(Video.duration_seconds), 0),
-        )
-        .where(Video.channel_id.in_(channel_ids))
-        .group_by(Video.channel_id)
-    )
-
-
 @router.get("")
 def list_channels(user: User = Depends(current_user), db: Session = Depends(get_db)) -> list[dict]:
-    rows = db.execute(
-        select(Subscription, Channel)
-        .join(Channel, Channel.id == Subscription.channel_id)
-        .where(Subscription.user_id == user.id)
-        .order_by(Subscription.priority.desc(), collated(Channel.title, lang_for_user(user)))
-    ).all()
+    rows = queries.subscriptions(db, user, lang_for_user(user))
 
     # Per-channel aggregates over the shared catalog (channel_aggregates), computed on read rather than
     # denormalised: an Index Only Scan over a ~20 MB index, where it used to read every video's heap page
@@ -70,36 +46,21 @@ def list_channels(user: User = Depends(current_user), db: Session = Depends(get_
     # computed here — the manager table dropped its N/S/L column.)
     channel_ids = [c.id for _, c in rows]
     agg: dict[str, dict] = {}
-    if channel_ids:
-        for cid, n, last_up, total_dur in db.execute(channel_aggregates(channel_ids)).all():
-            agg[cid] = {
-                "stored": n,
-                "last_video_at": iso(last_up),
-                "total_duration_seconds": int(total_dur or 0),
-            }
+    for cid, n, last_up, total_dur in queries.aggregates(db, channel_ids):
+        agg[cid] = {
+            "stored": n,
+            "last_video_at": iso(last_up),
+            "total_duration_seconds": int(total_dur or 0),
+        }
 
     # Channels already in the *global* deep-backfill queue — i.e. at least one user (any
     # user) has requested full history and it isn't done yet. Their whole back-catalogue is
     # coming for everyone (video data is shared), so the UI shouldn't offer "get full
     # history" to a user who simply hasn't personally opted in.
-    deep_queued: set[str] = set()
-    if channel_ids:
-        for (cid,) in db.execute(
-            select(Subscription.channel_id)
-            .where(
-                Subscription.channel_id.in_(channel_ids),
-                Subscription.deep_requested.is_(True),
-            )
-            .distinct()
-        ).all():
-            deep_queued.add(cid)
+    deep_queued = queries.deep_queued(db, channel_ids)
 
     # The user's personal tag links, grouped by channel.
-    tags_by_channel: dict[str, list[int]] = {}
-    for cid, tag_id in db.execute(
-        select(ChannelTag.channel_id, ChannelTag.tag_id).where(ChannelTag.user_id == user.id)
-    ).all():
-        tags_by_channel.setdefault(cid, []).append(tag_id)
+    tags_by_channel = reader_queries.user_tag_links(db, user)
 
     return [
         {
@@ -128,27 +89,7 @@ DISCOVERY_ENRICH_CAP = 200
 def _discovery_rows(db: Session, user: User) -> list:
     """The user's playlist channels they don't subscribe to (and that aren't their own),
     each with how many playlist videos come from it and across how many playlists."""
-    subscribed = select(Subscription.channel_id).where(Subscription.user_id == user.id)
-    q = (
-        select(
-            Channel,
-            func.count(func.distinct(PlaylistItem.video_id)),
-            func.count(func.distinct(Playlist.id)),
-        )
-        .select_from(PlaylistItem)
-        .join(Playlist, Playlist.id == PlaylistItem.playlist_id)
-        .join(Video, Video.id == PlaylistItem.video_id)
-        .join(Channel, Channel.id == Video.channel_id)
-        .where(Playlist.user_id == user.id, Channel.id.not_in(subscribed))
-    )
-    if user.yt_channel_id:
-        q = q.where(Channel.id != user.yt_channel_id)
-    return db.execute(
-        q.group_by(Channel.id).order_by(
-            func.count(func.distinct(PlaylistItem.video_id)).desc(),
-            collated(Channel.title, lang_for_user(user)),
-        )
-    ).all()
+    return reader_queries.playlist_channels(db, user, user.yt_channel_id, lang_for_user(user))
 
 
 @router.get("/discovery")
@@ -170,7 +111,7 @@ def discover_channels(
             ):
                 own = yt.get_my_channel_id()
             if own:
-                user.yt_channel_id = own
+                service.remember_own_channel(user, own)
                 db.commit()
         except YouTubeError as exc:
             # No traceback anywhere in this file's YouTube handlers: for an upstream answer
@@ -226,7 +167,7 @@ def discover_channels(
     ]
 
 
-def _channel_summary(ch: Channel) -> dict:
+def _channel_summary(ch: "Channel") -> dict:
     """The channel fields common to the list and discovery projections."""
     return {
         "id": ch.id,
@@ -240,7 +181,7 @@ def _channel_summary(ch: Channel) -> dict:
 
 
 def _channel_detail_dict(
-    channel: Channel,
+    channel: "Channel",
     *,
     subscribed: bool,
     explored: bool,
@@ -309,7 +250,7 @@ def channel_detail(
     needed (a stub) and refreshes it once it is stale (`DETAILS_MAX_AGE`), which is how a channel nobody subscribes to (an explored one, outside the
     subscription import) gets a banner that still resolves. The enrich uses the API key (1 unit,
     cached after)."""
-    channel = get_or_404(db, Channel, channel_id, what="channel")
+    channel = _channel_or_404(db, channel_id)
     # No `published_at is None` sentinel: a terminated channel never gets one, so it re-fetched on
     # every view; rows enriched before that field existed are long past DETAILS_MAX_AGE anyway.
     stale = details_stale(channel, datetime.now(timezone.utc))
@@ -321,7 +262,7 @@ def channel_detail(
             ):
                 apply_channel_details(db, yt.get_channels([channel_id]), [channel_id])
             db.commit()
-            channel = db.get(Channel, channel_id)
+            channel = _channel_or_404(db, channel_id)
         except YouTubeError as exc:
             log.warning(
                 "channel detail enrich failed: %s",
@@ -331,41 +272,15 @@ def channel_detail(
                 ),
             )
             db.rollback()
-    sub = db.execute(
-        select(Subscription).where(
-            Subscription.user_id == user.id, Subscription.channel_id == channel_id
-        )
-    ).scalar_one_or_none()
+    sub = queries.subscription(db, user, channel_id)
     subscribed = sub is not None
-    explored = (
-        db.execute(
-            select(ExploredChannel.id).where(
-                ExploredChannel.user_id == user.id, ExploredChannel.channel_id == channel_id
-            )
-        ).first()
-        is not None
-    )
-    blocked = _is_blocked(db, user, channel_id)
+    explored = queries.exploration(db, user, channel_id) is not None
+    blocked = queries.is_blocked(db, user, channel_id)
     # Stored total + the Normal/Shorts/Live split in one grouped pass (same filters as the manager
     # list), so the channel page can show the per-type breakdown that moved off the table.
-    n_all, n_short, n_live = db.execute(
-        select(
-            func.count(Video.id),
-            func.count(Video.id).filter(Video.is_short.is_(True)),
-            func.count(Video.id).filter(Video.live_status.in_(LIVE_OR_UPCOMING)),
-        ).where(Video.channel_id == channel_id)
-    ).one()
-    stored = int(n_all or 0)
-    count_short = int(n_short or 0)
-    count_live = int(n_live or 0)
+    stored, count_short, count_live = queries.video_counts(db, channel_id)
     count_normal = max(0, stored - count_short - count_live)
-    tag_ids = list(
-        db.scalars(
-            select(ChannelTag.tag_id).where(
-                ChannelTag.user_id == user.id, ChannelTag.channel_id == channel_id
-            )
-        ).all()
-    )
+    tag_ids = reader_queries.user_tag_links(db, user, channel_id).get(channel_id, [])
     return _channel_detail_dict(
         channel,
         subscribed=subscribed,
@@ -395,28 +310,15 @@ def explore_channel(
     it, then ingests one page of its uploads (newest-first) marked via_explore + enriched.
     Returns the next page token so the page can "load more". Guarded against the shared
     backfill quota reserve."""
-    channel = get_or_404(db, Channel, channel_id, what="channel")
-    if _is_blocked(db, user, channel_id):
+    channel = _channel_or_404(db, channel_id)
+    if queries.is_blocked(db, user, channel_id):
         raise refused(403, "channel_blocked")
     if quota.backfill_reserve_reached():
         raise refused(429, "quota_reserve")
 
     # Record/refresh the exploration (DB only) before ingesting, so the explorer can see the
     # videos as soon as they land. Flag the channel ephemeral unless it's organically followed.
-    existing = db.execute(
-        select(ExploredChannel).where(
-            ExploredChannel.user_id == user.id, ExploredChannel.channel_id == channel_id
-        )
-    ).scalar_one_or_none()
-    if existing is None:
-        db.add(ExploredChannel(user_id=user.id, channel_id=channel_id))
-    else:
-        existing.created_at = datetime.now(timezone.utc)  # refresh the grace clock
-    followed = db.execute(
-        select(Subscription.id).where(Subscription.channel_id == channel_id).limit(1)
-    ).first()
-    if followed is None and not channel.from_explore:
-        channel.from_explore = True
+    service.explore(db, user, channel)
     db.commit()
 
     try:
@@ -430,7 +332,7 @@ def explore_channel(
             if details_stale(channel, datetime.now(timezone.utc)):
                 apply_channel_details(db, yt.get_channels([channel_id]), [channel_id])
                 db.commit()
-                channel = db.get(Channel, channel_id)
+                channel = _channel_or_404(db, channel_id)
             result = explore_ingest_page(db, yt, channel, page_token)
     except YouTubeError as exc:
         raise youtube_refusal(exc) from exc
@@ -442,30 +344,20 @@ def explore_channel(
     }
 
 
-def _user_subscription(db: Session, user: User, channel_id: str) -> Subscription:
-    sub = db.execute(
-        select(Subscription).where(
-            Subscription.user_id == user.id, Subscription.channel_id == channel_id
-        )
-    ).scalar_one_or_none()
+def _channel_or_404(db: Session, channel_id: str) -> "Channel":
+    channel = queries.channel(db, channel_id)
+    if channel is None:
+        raise not_found("channel")
+    return channel
+
+
+def _user_subscription(db: Session, user: User, channel_id: str) -> "Subscription":
+    sub = queries.subscription(db, user, channel_id)
     if sub is None:
         raise not_found("subscription")
     return sub
 
 
-def _is_blocked(db: Session, user: User, channel_id: str) -> bool:
-    """Whether this user has blocked this channel."""
-    return (
-        db.execute(
-            select(BlockedChannel.id).where(
-                BlockedChannel.user_id == user.id,
-                BlockedChannel.channel_id == channel_id,
-            )
-        ).first()
-        is not None
-    )
-
-
 class ChannelUpdateIn(BaseModel):
     # PATCH semantics: a field left unset (None) is untouched. Every field is optional so the
     # UI can send just the one control it changed. int/bool coercion + rejection of garbage
@@ -483,19 +375,14 @@ def update_channel(
     db: Session = Depends(get_db),
 ) -> dict:
     sub = _user_subscription(db, user, channel_id)
-    channel = db.get(Channel, channel_id)
-    deep_turned_on = False
-    if body.priority is not None:
-        sub.priority = body.priority
-    if body.hidden is not None:
-        sub.hidden = body.hidden
-    if body.deep_requested is not None:
-        # Opt this channel into (or out of) full-history backfill. The deep scheduler
-        # picks the flag up on its next run; turning it off won't undo already-fetched
-        # videos, it just stops further deep paging if nobody else still wants it.
-        want = body.deep_requested
-        deep_turned_on = want and not sub.deep_requested
-        sub.deep_requested = want
+    channel = queries.channel(db, channel_id)
+    deep_turned_on = service.update_subscription(
+        db,
+        sub,
+        priority=body.priority,
+        hidden=body.hidden,
+        deep_requested=body.deep_requested,
+    )
     db.commit()
 
     # Opting a channel into full history should give an immediate feed: if we haven't even
@@ -539,19 +426,8 @@ def reset_backfill(
     state (a "reset" trigger). Clears the channel's backfill markers, opts it back into deep
     backfill, and re-runs its recent pull immediately; the deep scheduler re-pages the full
     back-catalog on its next run. Idempotent — videos upsert by id, so nothing duplicates."""
-    channel = get_or_404(db, Channel, channel_id, what="channel")
-    channel.backfill_done = False
-    channel.backfill_cursor = None
-    channel.recent_synced_at = None
-    # Re-arm the demand-driven deep scheduler for this channel. run_deep_backfill gates on an
-    # EXISTS over subscriptions with deep_requested=True, so flip it on EVERY subscriber rather
-    # than requiring the admin to be personally subscribed (they reset from the manager, not
-    # their own feed). No-op row count if the channel has no subscribers.
-    db.execute(
-        update(Subscription)
-        .where(Subscription.channel_id == channel_id)
-        .values(deep_requested=True)
-    )
+    channel = _channel_or_404(db, channel_id)
+    service.reset_backfill(db, channel)
     db.commit()
     with quota.attribute(user.id, quota.QuotaAction.VIDEOS_BACKFILL_RECENT):
         run_recent_backfill(db, [channel], max_channels=1)
@@ -569,13 +445,8 @@ def subscribe(
     local subscription with YouTube's returned resource id and enriches the channel's metadata
     if it's still a stub, so the new row renders properly in the manager. It does NOT pull the
     channel's videos — the scheduler picks those up on its next run, like any subscribed channel."""
-    channel = get_or_404(db, Channel, channel_id, what="channel")
-    existing = db.execute(
-        select(Subscription).where(
-            Subscription.user_id == user.id, Subscription.channel_id == channel_id
-        )
-    ).scalar_one_or_none()
-    if existing is not None:
+    channel = _channel_or_404(db, channel_id)
+    if queries.subscription(db, user, channel_id) is not None:
         raise refused(409, "already_subscribed")
     with (
         quota.attribute(user.id, quota.QuotaAction.CHANNELS_SUBSCRIBE),
@@ -615,24 +486,7 @@ def subscribe(
                         reason=exc.reason,
                     ),
                 )
-    db.add(
-        Subscription(
-            user_id=user.id,
-            channel_id=channel_id,
-            yt_subscription_id=yt_sub_id or None,
-            subscribed_at=datetime.now(timezone.utc),
-        )
-    )
-    # Subscribing is the "keep" signal: a previously-explored channel becomes a normal organic
-    # one. Drop its ephemeral flags so the cleanup job leaves it alone and its videos stop being
-    # per-user private (they join the shared Library like any subscribed channel's uploads).
-    if channel.from_explore:
-        channel.from_explore = False
-        db.execute(
-            update(Video)
-            .where(Video.channel_id == channel_id, Video.via_explore.is_(True))
-            .values(via_explore=False)
-        )
+    service.record_subscription(db, user, channel, yt_sub_id)
     db.commit()
     return {"ok": True, "subscribed": channel_id}
 
@@ -659,7 +513,7 @@ def unsubscribe(
         # 422 (a real, explainable error → speaking modal), not 502 which the client treats as
         # a transient "connection lost" gateway blip.
         raise youtube_refusal(exc) from exc
-    db.delete(sub)
+    service.drop_subscription(db, sub)
     db.commit()
     return {"ok": True, "unsubscribed": channel_id}
 
@@ -667,16 +521,7 @@ def unsubscribe(
 @router.get("/blocked/list")
 def list_blocked(user: User = Depends(current_user), db: Session = Depends(get_db)) -> list[dict]:
     """The user's blocked channels (videos from these are excluded from their search/feed/explore)."""
-    rows = (
-        db.execute(
-            select(Channel)
-            .join(BlockedChannel, BlockedChannel.channel_id == Channel.id)
-            .where(BlockedChannel.user_id == user.id)
-            .order_by(collated(Channel.title, lang_for_user(user)))
-        )
-        .scalars()
-        .all()
-    )
+    rows = queries.blocked_channels(db, user, lang_for_user(user))
     return [
         {"id": c.id, "title": c.title, "handle": c.handle, "thumbnail_url": c.thumbnail_url}
         for c in rows
@@ -692,16 +537,9 @@ def block_channel(
     """Block a channel for this user: its videos won't appear in their live search (and won't be
     ingested for them) and are hidden from their feed / explore. Idempotent. The now-hidden
     un-kept search/explore videos are reclaimed by the discovery-cleanup job in due course."""
-    get_or_404(db, Channel, channel_id, what="channel")
-    if not _is_blocked(db, user, channel_id):
-        db.add(BlockedChannel(user_id=user.id, channel_id=channel_id))
-        # Stop any active exploration of it so it can be cleaned up.
-        db.execute(
-            ExploredChannel.__table__.delete().where(
-                (ExploredChannel.user_id == user.id) & (ExploredChannel.channel_id == channel_id)
-            )
-        )
-        db.commit()
+    _channel_or_404(db, channel_id)
+    service.block(db, user, channel_id)
+    db.commit()
     return {"ok": True, "blocked": channel_id}
 
 
@@ -711,11 +549,7 @@ def unblock_channel(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    db.execute(
-        BlockedChannel.__table__.delete().where(
-            (BlockedChannel.user_id == user.id) & (BlockedChannel.channel_id == channel_id)
-        )
-    )
+    service.unblock(db, user, channel_id)
     db.commit()
     return {"ok": True, "unblocked": channel_id}
 
@@ -732,26 +566,12 @@ def attach_tag(
     db: Session = Depends(get_db),
 ) -> dict:
     _user_subscription(db, user, channel_id)
-    # Only the user's own tags may be attached as personal links (owned_or_404 → 404 if the tag
-    # is missing OR belongs to someone else, without leaking which).
-    owned_or_404(db, Tag, body.tag_id, user, what="tag")
-    exists = db.execute(
-        select(ChannelTag).where(
-            ChannelTag.channel_id == channel_id,
-            ChannelTag.tag_id == body.tag_id,
-            ChannelTag.user_id == user.id,
-        )
-    ).scalar_one_or_none()
-    if exists is None:
-        db.add(
-            ChannelTag(
-                channel_id=channel_id,
-                tag_id=body.tag_id,
-                user_id=user.id,
-                source="user",
-            )
-        )
-        db.commit()
+    # Only the user's own tags may be attached as personal links (a 404 if the tag is missing OR
+    # belongs to someone else, without leaking which).
+    if reader_queries.own_tag(db, user, body.tag_id) is None:
+        raise not_found("tag")
+    reader_service.attach_user_tag(db, user, channel_id, body.tag_id)
+    db.commit()
     return {"ok": True, "channel_id": channel_id, "tag_id": body.tag_id}
 
 
@@ -762,14 +582,6 @@ def detach_tag(
     user: User = Depends(current_user),
     db: Session = Depends(get_db),
 ) -> dict:
-    row = db.execute(
-        select(ChannelTag).where(
-            ChannelTag.channel_id == channel_id,
-            ChannelTag.tag_id == tag_id,
-            ChannelTag.user_id == user.id,
-        )
-    ).scalar_one_or_none()
-    if row is not None:
-        db.delete(row)
-        db.commit()
+    reader_service.detach_user_tag(db, user, channel_id, tag_id)
+    db.commit()
     return {"ok": True, "channel_id": channel_id, "tag_id": tag_id}

backend/app/routes/runs.py

@@ -19,7 +19,7 @@ from app import scheduler
 from app.auth import admin_user
 from app.db import get_db
 from app.models import JobRun, LogEvent, User
-from app.catalog.models import Channel
+from app.catalog import queries as catalog_queries
 from app.routes import _account as account
 from app.routes._keyset import PAGE_MAX, accounts, older_than, page, utc
 from app.runstatus import RunStatus
@@ -117,10 +117,7 @@ def list_runs(
         lambda r: r.started_at,
     )
     channels = {r.target for r in runs if r.job in scheduler.AD_HOC_JOBS and r.target}
-    titles: dict[str, str] = {}
-    if channels:
-        rows = db.execute(select(Channel.id, Channel.title).where(Channel.id.in_(channels)))
-        titles = {cid: title for cid, title in rows.tuples() if title is not None}
+    titles = catalog_queries.channel_titles(db, channels)
     lines: dict[int, int] = {}
     if runs:
         counted = db.execute(

backend/app/routes/scheduler.py

@@ -4,7 +4,6 @@ and the shared quota picture."""
 
 from fastapi import APIRouter, Depends
 from pydantic import BaseModel
-from sqlalchemy import and_, func, or_, select
 from sqlalchemy.orm import Session
 
 from app import audit, quota, state, sysconfig
@@ -13,7 +12,7 @@ from app.auth import admin_user
 from app.config import settings
 from app.db import get_db
 from app.models import User
-from app.catalog.models import Channel, Subscription, Video
+from app.catalog import queries as catalog_queries
 from app.scheduler import (
     JOB_INTERVALS,
     MAX_INTERVAL,
@@ -24,7 +23,6 @@ from app.scheduler import (
     trigger_all,
     trigger_job,
 )
-from app.sync.explore import followed_channel
 from app.sync.runner import estimate_deep_backfill
 from app.routes._common import not_found
 from app.refusal import refused
@@ -123,58 +121,14 @@ def get_scheduler(_: User = Depends(admin_user), db: Session = Depends(get_db))
     snap = scheduler_snapshot(db)
 
     # Work still queued (shared catalog, so these are instance-wide, not per-user).
-    deep_requested = (
-        select(Subscription.id)
-        .where(
-            Subscription.channel_id == Channel.id,
-            Subscription.deep_requested.is_(True),
-        )
-        .exists()
-    )
-    deep_channels = (
-        db.execute(select(Channel).where(Channel.backfill_done.is_(False), deep_requested))
-        .scalars()
-        .all()
-    )
-    deep_eta = estimate_deep_backfill(db, deep_channels)
-
-    queue = {
-        "channels_recent_pending": db.scalar(
-            # The same selection run_recent_backfill works through, or the card counts channels
-            # the job will never touch and never reaches zero.
-            select(func.count())
-            .select_from(Channel)
-            .where(Channel.recent_synced_at.is_(None), followed_channel())
-        )
-        or 0,
-        # The whole opted-in BACKLOG, deliberately not `run_deep_backfill`'s next-pass selection
-        # (which also wants `recent_synced_at`): the same figure /api/sync/my-status shows the user,
-        # and a channel missing its recent pull is one the same job tick fetches first, not one the
-        # job will never touch. Narrowing it here would under-report work that is genuinely queued.
-        "channels_deep_pending": deep_eta["channels_pending"],
-        "deep_eta_seconds": deep_eta["eta_seconds"],
-        "videos_pending_enrich": db.scalar(
-            select(func.count()).select_from(Video).where(Video.enriched_at.is_(None))
-        )
-        or 0,
-        "videos_pending_shorts": db.scalar(
-            select(func.count())
-            .select_from(Video)
-            .where(Video.shorts_probed.is_(False), Video.enriched_at.is_not(None))
-        )
-        or 0,
-        "videos_live_refresh": db.scalar(
-            select(func.count())
-            .select_from(Video)
-            .where(
-                or_(
-                    Video.live_status.in_(("live", "upcoming")),
-                    and_(Video.live_status == "was_live", Video.duration_seconds.is_(None)),
-                )
-            )
-        )
-        or 0,
-    }
+    deep_eta = estimate_deep_backfill(db, catalog_queries.deep_backlog(db))
+    queue = catalog_queries.work_queue(db)
+    # The whole opted-in BACKLOG, deliberately not `run_deep_backfill`'s next-pass selection
+    # (which also wants `recent_synced_at`): the same figure /api/sync/my-status shows the user,
+    # and a channel missing its recent pull is one the same job tick fetches first, not one the
+    # job will never touch. Narrowing it here would under-report work that is genuinely queued.
+    queue["channels_deep_pending"] = deep_eta["channels_pending"]
+    queue["deep_eta_seconds"] = deep_eta["eta_seconds"]
 
     used = quota.units_used_today(db)
     quota_info = {

backend/app/routes/search.py

@@ -11,37 +11,24 @@ regardless of source.
 Ingested results are flagged (videos.via_search / channels.from_search) so the Library can hide
 this search-discovered "noise" by default. Shorts and currently-live/upcoming videos are never
 ingested this way (Shorts are confirmed by the youtube.com/shorts probe; live/upcoming are
-dropped from the search response up front)."""
+dropped from the search response up front).
 
-from concurrent.futures import ThreadPoolExecutor
-from datetime import datetime, timezone
+This is the HTTP side — the paging, the caps and the refusals; what a page of results leaves in the
+catalog is `catalog/search`."""
 
 from fastapi import APIRouter, Depends
 from pydantic import BaseModel
-from sqlalchemy import and_, delete, func, or_, select, update
-from sqlalchemy.dialects.postgresql import insert as pg_insert
-from sqlalchemy.orm import Session, aliased
+from sqlalchemy.orm import Session
 
 from app import logs, quota, sysconfig
 from app.auth import current_user
+from app.catalog import queries
+from app.catalog import search as catalog_search
 from app.db import get_db
 from app.models import User
-from app.catalog.models import (
-    LIVE_OR_UPCOMING,
-    BlockedChannel,
-    Channel,
-    SearchFind,
-    Subscription,
-    Video,
-)
-from app.reader.models import Playlist, PlaylistItem, VideoState
-from app.feedquery import feed_columns, serialize
-from app.utils import like_escape
-from app.sync.subscriptions import apply_channel_details
-from app.sync.videos import insert_stubs, apply_video_details, parse_dt
+from app.reader import queries as reader_queries
 from app.youtube import search_scrape
 from app.youtube.client import YouTubeClient, YouTubeError
-from app.youtube.shorts import make_client, probe_is_short
 from app.refusal import refused
 from app.routes._common import youtube_refusal
 
@@ -52,198 +39,6 @@ router = APIRouter(prefix="/api/search", tags=["search"])
 SEARCH_COST = 100
 
 
-def _classify_shorts(db: Session, videos: list[Video]) -> None:
-    """Confirm/deny Shorts for the freshly-ingested videos so none slip into the feed.
-
-    Mirrors the scheduler's run_shorts_classification, but scoped to just these rows and run
-    synchronously (the search is an explicit, awaited action). Non-candidates (too long, no
-    duration, or live) are finalised without a probe; the rest hit youtube.com/shorts (no
-    quota). Undetermined probes are left for the scheduler to retry."""
-    probe_max = sysconfig.get_int(db, "shorts_probe_max_seconds")
-    to_probe: list[Video] = []
-    for v in videos:
-        if v.shorts_probed:
-            continue
-        if v.enriched_at is None:
-            # Enrichment failed (proxy blip) or YouTube omitted the row — duration is unknown,
-            # so DON'T finalise shorts_probed off a null duration; leave it for the scheduler
-            # (which only classifies enriched rows) to retry. Otherwise a real Short would leak.
-            continue
-        if v.live_status != "none" or v.duration_seconds is None or v.duration_seconds > probe_max:
-            v.is_short = False
-            v.shorts_probed = True
-        else:
-            to_probe.append(v)
-    if to_probe:
-        with make_client() as client:
-
-            def work(v: Video):
-                return v, probe_is_short(client, v.id)
-
-            with ThreadPoolExecutor(max_workers=16) as pool:
-                for v, result in pool.map(work, to_probe):
-                    if result is None:
-                        continue
-                    v.is_short = result
-                    v.shorts_probed = True
-    db.commit()
-
-
-def _serialize_ids(db: Session, user: User, ids: list[str]) -> list[dict]:
-    """Serialize the given video ids with the shared feed projection (joined channel + this
-    user's watch state + saved), preserving the input (search relevance) order."""
-    if not ids:
-        return []
-    state = aliased(VideoState)
-    rows = db.execute(
-        select(*feed_columns(user, state))
-        .join(Channel, Channel.id == Video.channel_id)
-        .outerjoin(state, and_(state.video_id == Video.id, state.user_id == user.id))
-        .where(Video.id.in_(ids))
-    ).all()
-    by_id = {r.id: serialize(r) for r in rows}
-    return [by_id[i] for i in ids if i in by_id]
-
-
-def _ingest_candidates(
-    db: Session, yt: YouTubeClient, user: User, candidates: list[dict]
-) -> list[str]:
-    """Materialise one page of search candidates into the catalog (channel stubs + enrich,
-    video stubs flagged via_search, enrich, Shorts classification) and return the KEEPABLE
-    video ids — non-Short, non-live — in the input relevance order."""
-    ids = [it["id"] for it in candidates]
-    if not ids:
-        return []
-
-    # 1) Channels are the FK target — create stubs for unknown ones (flagged from_search),
-    #    then enrich the new ones (channels.list, 1 unit). Stubs survive an enrich failure.
-    channel_ids = list({it["channel_id"] for it in candidates})
-    existing = set(db.scalars(select(Channel.id).where(Channel.id.in_(channel_ids))).all())
-    new_channel_ids = [c for c in channel_ids if c not in existing]
-    if new_channel_ids:
-        titles = {it["channel_id"]: it["channel_title"] for it in candidates}
-        for cid in new_channel_ids:
-            db.add(Channel(id=cid, title=titles.get(cid), from_search=True))
-        db.commit()
-        try:
-            with quota.attribute(user.id, quota.QuotaAction.CHANNELS_DISCOVER):
-                details = yt.get_channels(new_channel_ids)
-            apply_channel_details(db, details, new_channel_ids)
-            db.commit()
-        except YouTubeError:
-            # The stubs remain and the details can be backfilled later — but until they are, those
-            # channels sit in the results with no thumbnail and no subscriber count, looking like
-            # channels that have neither.
-            log.warning(
-                "the channels found by a search could not be enriched",
-                extra=logs.event("search.channel_enrich_failed", channels=len(new_channel_ids)),
-            )
-            db.rollback()  # details can be backfilled later; the stubs remain
-
-    # 2) Video stubs, flagged via_search. Existing rows keep their flags (ON CONFLICT DO
-    #    NOTHING), so an organically-synced video stays organic.
-    #    published_at is NOT NULL (migration 0068); the scrape source exposes no publish date
-    #    (only a relative "3 years ago"), so fall back to now() to satisfy the constraint — the
-    #    enrich in step 3 overwrites it with the video's real snippet date.
-    now = datetime.now(timezone.utc)
-    insert_stubs(
-        db,
-        [
-            {
-                "id": it["id"],
-                "channel_id": it["channel_id"],
-                "title": it["title"],
-                "published_at": parse_dt(it["published_at"]) or now,
-                "thumbnail_url": it["thumbnail_url"],
-                "via_search": True,
-            }
-            for it in candidates
-        ],
-    )
-
-    # 3) Enrich (videos.list, 1 unit/50) so cards have duration/stats and we can judge live.
-    videos = db.scalars(select(Video).where(Video.id.in_(ids))).all()
-    try:
-        with quota.attribute(user.id, quota.QuotaAction.VIDEOS_ENRICH):
-            detail_by_id = {it["id"]: it for it in yt.get_videos(ids)}
-    except YouTubeError:
-        # Every candidate then stays unenriched, and an unenriched video cannot be judged live or
-        # Short — so it is dropped. A working search returns nothing and reads as "no results".
-        log.warning(
-            "the videos found by a search could not be enriched",
-            extra=logs.event("search.video_enrich_failed", candidates=len(ids)),
-        )
-        detail_by_id = {}
-    enriched_at = datetime.now(
-        timezone.utc
-    )  # when THIS enrich ran (distinct from the stub placeholder)
-    for v in videos:
-        item = detail_by_id.get(v.id)
-        if item is None:
-            continue
-        apply_video_details(v, item)
-        v.enriched_at = enriched_at
-    db.commit()
-
-    # 4) Confirm/deny Shorts (no quota) so none enter via search.
-    _classify_shorts(db, videos)
-
-    keep = {
-        v.id
-        for v in videos
-        if v.enriched_at is not None and not v.is_short and v.live_status not in LIVE_OR_UPCOMING
-    }
-    return [vid for vid in ids if vid in keep]
-
-
-def _new_first(db: Session, user: User, ids: list[str]) -> list[str]:
-    """Reorder results so genuinely-new discoveries come first and things the user already has
-    (a subscribed channel, or a video they've watched / in-progress / saved / playlisted) sink
-    to the back — keeping the relevance order within each group."""
-    if not ids:
-        return ids
-    sub_ch = select(Subscription.channel_id).where(Subscription.user_id == user.id)
-    has_state = (
-        select(VideoState.id)
-        .where(VideoState.video_id == Video.id, VideoState.user_id == user.id)
-        .exists()
-    )
-    in_playlist = (
-        select(PlaylistItem.id)
-        .join(Playlist, Playlist.id == PlaylistItem.playlist_id)
-        .where(PlaylistItem.video_id == Video.id, Playlist.user_id == user.id)
-        .exists()
-    )
-    have = set(
-        db.scalars(
-            select(Video.id).where(
-                Video.id.in_(ids),
-                or_(Video.channel_id.in_(sub_ch), has_state, in_playlist),
-            )
-        ).all()
-    )
-    return [i for i in ids if i not in have] + [i for i in ids if i in have]
-
-
-def _fold_term(db: Session, video_ids: list[str], term: str) -> None:
-    """Append `term` to each video's space-joined `search_terms`, unless it is already one of them.
-
-    "Already one of them" is a whole-term match, as a literal: a substring test skipped `cat` on a
-    video already found for `category`, and an unescaped one read the `_` in `my_channel` as a
-    wildcard — either way the term was never folded in, and local search lost that relevance."""
-    padded = func.concat(" ", func.coalesce(Video.search_terms, ""), " ")
-    db.execute(
-        update(Video)
-        .where(Video.id.in_(video_ids))
-        .where(padded.notilike(f"% {like_escape(term)} %"))
-        .values(
-            search_terms=func.trim(
-                func.coalesce(Video.search_terms, "").op("||")(" ").op("||")(term)
-            )
-        )
-    )
-
-
 @router.get("/youtube")
 def search_youtube(
     q: str | None = None,
@@ -285,9 +80,7 @@ def search_youtube(
         raise refused(429, "quota_spent")
 
     # Channels this user has blocked are dropped before ingestion — never shown, never stored.
-    blocked = set(
-        db.scalars(select(BlockedChannel.channel_id).where(BlockedChannel.user_id == user.id)).all()
-    )
+    blocked = queries.blocked_ids(db, user)
 
     collected: list[str] = []
     next_cursor = cursor
@@ -328,7 +121,7 @@ def search_youtube(
             # write/shape failure degrades to a 422 with a message on this JSON endpoint instead of a
             # bare 500 hidden behind the FE's generic "search failed" (same rationale as B-core-1).
             try:
-                collected.extend(_ingest_candidates(db, yt, user, candidates))
+                collected.extend(catalog_search.ingest_candidates(db, yt, user, candidates))
             except Exception as exc:  # any ingest failure, not just YouTubeError
                 db.rollback()
                 # The term is NOT in this line. A search string is exactly what the privacy
@@ -376,17 +169,12 @@ def search_youtube(
         # Record these as THIS user's search finds (Mine feed / Source filter), and fold the
         # query into each result's search_terms so local full-text search inherits YouTube's
         # relevance. Idempotent; the generated search_vector updates automatically.
-        db.execute(
-            pg_insert(SearchFind)
-            .values([{"user_id": user.id, "video_id": vid} for vid in ordered])
-            .on_conflict_do_nothing(index_elements=["user_id", "video_id"])
-        )
-        _fold_term(db, ordered, term)
+        catalog_search.record_finds(db, user, ordered, term)
         db.commit()
 
-    ordered = _new_first(db, user, ordered)
+    ordered = catalog_search.new_first(db, user, ordered)
     return {
-        "items": _serialize_ids(db, user, ordered),
+        "items": reader_queries.feed_rows_by_ids(db, user, ordered),
         "next_cursor": next_cursor,
         "has_more": bool(next_cursor),
         "source": source,
@@ -410,23 +198,6 @@ def clear_search(
     ids = body.video_ids
     if not ids:
         return {"ok": True, "removed": 0}
-    db.execute(
-        delete(SearchFind).where(SearchFind.user_id == user.id, SearchFind.video_id.in_(ids))
-    )
-    db.commit()
-    has_state = select(VideoState.id).where(VideoState.video_id == Video.id).exists()
-    in_playlist = select(PlaylistItem.id).where(PlaylistItem.video_id == Video.id).exists()
-    subscribed = select(Subscription.id).where(Subscription.channel_id == Video.channel_id).exists()
-    other_find = select(SearchFind.id).where(SearchFind.video_id == Video.id).exists()
-    removed = db.execute(
-        delete(Video).where(
-            Video.id.in_(ids),
-            Video.via_search.is_(True),
-            ~has_state,
-            ~in_playlist,
-            ~subscribed,
-            ~other_find,
-        )
-    ).rowcount
+    removed = catalog_search.clear(db, user, ids)
     db.commit()
     return {"ok": True, "removed": removed}

backend/app/routes/sync.py

@@ -1,5 +1,4 @@
 from fastapi import APIRouter, Depends, HTTPException
-from sqlalchemy import and_, case, func, select, update
 from sqlalchemy.orm import Session
 
 from app import audit, quota, state
@@ -7,7 +6,7 @@ from app.audit import AuditAction
 from app.auth import admin_user, current_user, has_read_scope
 from app.db import get_db
 from app.models import User
-from app.catalog.models import Channel, Subscription, Video
+from app.catalog import queries, service
 from app.routes._common import youtube_refusal
 from app.ratelimit import RateLimiter
 from app.sync.runner import estimate_deep_backfill
@@ -48,19 +47,8 @@ def sync_subscriptions(user: User = Depends(current_user), db: Session = Depends
 
 @router.get("/status")
 def sync_status(user: User = Depends(current_user), db: Session = Depends(get_db)) -> dict:
-    sub_count = db.scalar(
-        select(func.count()).select_from(Subscription).where(Subscription.user_id == user.id)
-    )
     return {
-        "subscriptions": sub_count,
-        "channels_total": db.scalar(select(func.count()).select_from(Channel)),
-        "channels_backfilling": db.scalar(
-            select(func.count()).select_from(Channel).where(Channel.backfill_done.is_(False))
-        ),
-        "videos_total": db.scalar(select(func.count()).select_from(Video)),
-        "pending_enrich": db.scalar(
-            select(func.count()).select_from(Video).where(Video.enriched_at.is_(None))
-        ),
+        **queries.catalog_totals(db, user),
         "quota_used_today": quota.units_used_today(db),
         "quota_remaining_today": quota.remaining_today(db),
         "paused": state.is_sync_paused(db),
@@ -71,51 +59,21 @@ def sync_status(user: User = Depends(current_user), db: Session = Depends(get_db
 @router.get("/my-status")
 def my_status(user: User = Depends(current_user), db: Session = Depends(get_db)) -> dict:
     """Per-user sync progress: how far the channels *this* user subscribes to have synced."""
-    sub_join = and_(Subscription.channel_id == Channel.id, Subscription.user_id == user.id)
-    total, details_synced, recent_synced, all_deep_done = db.execute(
-        select(
-            func.count(Channel.id),
-            func.count(Channel.details_synced_at),
-            func.count(Channel.recent_synced_at),
-            func.sum(case((Channel.backfill_done.is_(True), 1), else_=0)),
-        )
-        .select_from(Channel)
-        .join(Subscription, sub_join)
-    ).one()
-    total = total or 0
-    all_deep_done = int(all_deep_done or 0)
+    total, details_synced, recent_synced, all_deep_done = queries.my_progress(db, user)
 
     # Per-user full-history (deep) backfill: channels this user has opted in, and an ETA
     # for the still-pending ones (quota-bound estimate).
-    deep_requested_channels = (
-        db.execute(
-            select(Channel).join(
-                Subscription,
-                and_(sub_join, Subscription.deep_requested.is_(True)),
-            )
-        )
-        .scalars()
-        .all()
-    )
+    deep_requested_channels = queries.my_deep_requested(db, user)
     deep_eta = estimate_deep_backfill(db, deep_requested_channels)
     # "done / requested" is shown as one ratio, so both halves count the SAME channels: the ones this
     # user asked full history for. Counting every subscribed channel whose back-catalog happens to be
     # complete (another user asked, or it was short) gave "342/329".
     deep_done = sum(1 for c in deep_requested_channels if c.backfill_done)
 
-    my_videos = db.scalar(
-        select(func.count(Video.id)).join(
-            Subscription,
-            and_(
-                Subscription.channel_id == Video.channel_id,
-                Subscription.user_id == user.id,
-                Subscription.hidden.is_(False),
-            ),
-        )
-    )
+    my_videos = queries.my_video_count(db, user)
     # Whole-catalog total (every video any user's subscriptions have pulled in), so the
     # header can show "yours" against the shared library size.
-    total_videos = db.scalar(select(func.count(Video.id)))
+    total_videos = queries.video_total(db)
     return {
         "channels_total": total,
         "channels_details_synced": details_synced,
@@ -126,8 +84,8 @@ def my_status(user: User = Depends(current_user), db: Session = Depends(get_db))
         "channels_deep_requested": len(deep_requested_channels),
         "deep_pending_count": deep_eta["channels_pending"],
         "deep_eta_seconds": deep_eta["eta_seconds"],
-        "my_videos": my_videos or 0,
-        "total_videos": total_videos or 0,
+        "my_videos": my_videos,
+        "total_videos": total_videos,
         "quota_used_today": quota.units_used_today(db),
         "quota_remaining_today": quota.remaining_today(db),
         "paused": state.is_sync_paused(db),
@@ -144,11 +102,9 @@ def deep_all(
     on: bool = True,
 ) -> dict:
     """Opt every one of the user's channels into (or out of) full-history backfill."""
-    result = db.execute(
-        update(Subscription).where(Subscription.user_id == user.id).values(deep_requested=on)
-    )
+    updated = service.set_deep_all(db, user, on)
     db.commit()
-    return {"ok": True, "updated": result.rowcount, "deep_requested": on}
+    return {"ok": True, "updated": updated, "deep_requested": on}
 
 
 @router.post("/pause")

backend/app/scheduler.py

@@ -9,14 +9,13 @@ from typing import Callable
 from apscheduler.executors.pool import ThreadPoolExecutor
 from apscheduler.jobstores.base import ConflictingIdError
 from apscheduler.schedulers.background import BackgroundScheduler
-from sqlalchemy import select
 
 from app import audit, debugsession, jobruns, logs, logsink, progress, quota, sysconfig
 from app.config import settings
 from app.db import SessionLocal
 from app.downloads.gc import run_download_gc
 from app.models import JobRun
-from app.catalog.models import Channel
+from app.catalog import queries as catalog_queries
 from app.plex.sync import sync as run_plex_sync
 from app.plex.tmdb import run_enrich as run_tmdb_enrich
 from app.plex.tmdb import run_people_enrich
@@ -306,7 +305,7 @@ def scheduler_snapshot(db) -> dict:
             "running": going is not None,
             "target": shown.target if shown else None,
             "target_title": (
-                db.scalar(select(Channel.title).where(Channel.id == shown.target))
+                catalog_queries.channel_title(db, shown.target)
                 if shown is not None and shown.target
                 else None
             ),

backend/app/sync/subscriptions.py

@@ -11,6 +11,7 @@ from app.models import User
 from app.catalog.models import Channel, Subscription
 from app.utils import normalize_description
 from app.youtube.client import YouTubeClient, YouTubeError, best_thumbnail
+from app.userscope import owned_by
 
 log = logs.get_logger(__name__)
 
@@ -173,7 +174,7 @@ def import_subscriptions(db: Session, user: User) -> dict:
                 new_channels += 1
             sub_row = db.execute(
                 select(Subscription).where(
-                    Subscription.user_id == user.id, Subscription.channel_id == cid
+                    owned_by(Subscription.user_id, user.id), Subscription.channel_id == cid
                 )
             ).scalar_one_or_none()
             if sub_row is None:
@@ -186,7 +187,9 @@ def import_subscriptions(db: Session, user: User) -> dict:
         # (see `should_prune`).
         removed = 0
         existing = (
-            db.execute(select(Subscription).where(Subscription.user_id == user.id)).scalars().all()
+            db.execute(select(Subscription).where(owned_by(Subscription.user_id, user.id)))
+            .scalars()
+            .all()
         )
         prune_skipped = not should_prune(len(fetched), len(existing))
         if prune_skipped: