"""Catalog's service and queries, one use case each, below the HTTP layer.

The routes are thin callers now, and their own tests stay the contract a client sees. These hold
what each write does and leaves on its own: that it flushes and leaves the commit to its caller,
that a row of someone else's reads as a missing one, and the rule each write carries (an explored
channel flagged only while nobody follows it, a subscription that keeps it, a cleared search that
spares what anyone holds). DB-backed (real Postgres).
"""

from datetime import datetime, timedelta, timezone

from sqlalchemy import select

from app.catalog import queries, search, service
from app.catalog.models import (
    BlockedChannel,
    Channel,
    ExploredChannel,
    SearchFind,
    Subscription,
    Video,
)
from app.reader import queries as reader_queries
from app.reader import service as reader_service


def _channel(db, cid="UCc", **kw):
    ch = Channel(id=cid, title=kw.pop("title", cid), **kw)
    db.add(ch)
    db.commit()
    return ch


def _video(db, vid, cid="UCc", **kw):
    v = Video(id=vid, channel_id=cid, published_at=datetime.now(timezone.utc), **kw)
    db.add(v)
    db.commit()
    return v


def _sub(db, user, cid="UCc", **kw):
    s = Subscription(user_id=user.id, channel_id=cid, **kw)
    db.add(s)
    db.commit()
    return s


def _uncommitted(db):
    return bool(db.new or db.dirty or db.deleted) or db.in_transaction()


# --- whose a row is ------------------------------------------------------------------------


def test_a_users_subscriptions_blocks_and_explorations_are_theirs_alone(db, make_user):
    owner, stranger = make_user(), make_user()
    ch = _channel(db)
    _sub(db, owner)
    service.explore(db, owner, ch)
    service.block(db, owner, "UCc")
    db.commit()
    assert queries.subscription(db, owner, "UCc") is not None
    assert queries.subscription(db, stranger, "UCc") is None
    assert queries.exploration(db, stranger, "UCc") is None
    assert queries.is_blocked(db, stranger, "UCc") is False
    assert queries.blocked_ids(db, stranger) == set()
    assert [s.channel_id for s, _ in queries.subscriptions(db, stranger, "en")] == []


# --- subscription settings -------------------------------------------------------------------


def test_full_history_reports_only_the_switch_on(db, make_user):
    user = make_user()
    _channel(db)
    sub = _sub(db, user)
    assert service.update_subscription(db, sub, priority=3) is False
    assert service.update_subscription(db, sub, deep_requested=True) is True
    assert service.update_subscription(db, sub, deep_requested=True) is False  # already on
    assert _uncommitted(db)
    db.commit()
    assert (sub.priority, sub.hidden, sub.deep_requested) == (3, False, True)


def test_full_history_for_all_moves_only_the_callers_rows(db, make_user):
    user, other = make_user(), make_user()
    _channel(db)
    _sub(db, user)
    theirs = _sub(db, other)
    assert service.set_deep_all(db, user, True) == 1
    db.commit()
    db.expire_all()
    assert theirs.deep_requested is False


def test_a_reset_asks_every_subscriber_for_full_history(db, make_user):
    a, b = make_user(), make_user()
    ch = _channel(db, backfill_done=True, recent_synced_at=datetime.now(timezone.utc))
    _sub(db, a)
    _sub(db, b)
    service.reset_backfill(db, ch)
    db.commit()
    db.expire_all()
    assert (ch.backfill_done, ch.recent_synced_at) == (False, None)
    assert set(db.scalars(select(Subscription.deep_requested))) == {True}


# --- explore, subscribe, block ---------------------------------------------------------------


def test_an_exploration_is_one_row_and_flags_the_channel_only_while_nobody_follows_it(
    db, make_user
):
    explorer, follower = make_user(), make_user()
    lone = _channel(db, "UClone")
    kept = _channel(db, "UCkept")
    _sub(db, follower, "UCkept")
    service.explore(db, explorer, lone)
    service.explore(db, explorer, kept)
    db.commit()
    first = queries.exploration(db, explorer, "UClone").created_at
    service.explore(db, explorer, lone)  # refreshes the grace clock
    db.commit()
    assert db.scalar(select(ExploredChannel.id).where(ExploredChannel.channel_id == "UClone"))
    assert len(db.scalars(select(ExploredChannel.id)).all()) == 2
    assert queries.exploration(db, explorer, "UClone").created_at >= first
    assert (lone.from_explore, kept.from_explore) == (True, False)


def test_subscribing_keeps_an_explored_channel_and_its_videos(db, make_user):
    user = make_user()
    ch = _channel(db, from_explore=True)
    v = _video(db, "v1", via_explore=True)
    service.record_subscription(db, user, ch, "")
    db.commit()
    db.expire_all()
    sub = queries.subscription(db, user, "UCc")
    assert (sub.yt_subscription_id, ch.from_explore, v.via_explore) == (None, False, False)
    service.drop_subscription(db, sub)
    db.commit()
    assert queries.subscription(db, user, "UCc") is None


def test_a_block_is_once_and_ends_the_exploration(db, make_user):
    user = make_user()
    ch = _channel(db)
    service.explore(db, user, ch)
    db.commit()
    service.block(db, user, "UCc")
    service.block(db, user, "UCc")
    db.commit()
    assert len(db.scalars(select(BlockedChannel.id)).all()) == 1
    assert queries.exploration(db, user, "UCc") is None
    assert [c.id for c in queries.blocked_channels(db, user, "en")] == ["UCc"]
    service.unblock(db, user, "UCc")
    db.commit()
    assert queries.is_blocked(db, user, "UCc") is False


# --- what the status cards count -------------------------------------------------------------


def test_my_progress_counts_only_my_channels_and_my_unhidden_videos(db, make_user):
    user, other = make_user(), make_user()
    now = datetime.now(timezone.utc)
    _channel(db, "UCa", details_synced_at=now, recent_synced_at=now, backfill_done=True)
    _channel(db, "UCb")
    _channel(db, "UCtheirs")
    _video(db, "a1", "UCa")
    _video(db, "b1", "UCb")
    _video(db, "t1", "UCtheirs")
    _sub(db, user, "UCa", deep_requested=True)
    _sub(db, user, "UCb", hidden=True)
    _sub(db, other, "UCtheirs")
    assert queries.my_progress(db, user) == (2, 1, 1, 1)
    assert [c.id for c in queries.my_deep_requested(db, user)] == ["UCa"]
    assert queries.my_video_count(db, user) == 1
    assert queries.video_total(db) == 3
    assert queries.catalog_totals(db, user)["subscriptions"] == 2


def test_a_channel_with_no_title_is_left_out_of_the_titles(db):
    _channel(db, "UCt", title="Titled")
    db.add(Channel(id="UCn", title=None))
    db.commit()
    assert queries.channel_titles(db, {"UCt", "UCn", "UCgone"}) == {"UCt": "Titled"}
    assert queries.channel_title(db, "UCt") == "Titled"


def test_the_deep_backlog_is_the_unfinished_channels_someone_asked_for(db, make_user):
    user = make_user()
    _channel(db, "UCwant")
    _channel(db, "UCdone", backfill_done=True)
    _channel(db, "UCnobody")
    _sub(db, user, "UCwant", deep_requested=True)
    _sub(db, user, "UCdone", deep_requested=True)
    _sub(db, user, "UCnobody")
    assert [c.id for c in queries.deep_backlog(db)] == ["UCwant"]
    assert queries.deep_queued(db, ["UCwant", "UCdone", "UCnobody"]) == {"UCwant", "UCdone"}


# --- live search -----------------------------------------------------------------------------


def test_a_cleared_search_spares_what_anyone_holds(db, make_user):
    user, other, follower = make_user(), make_user(), make_user()
    _channel(db, "UCs")
    _channel(db, "UCfollowed")
    _sub(db, follower, "UCfollowed")
    for vid in ("loose", "watched", "found_by_other"):
        _video(db, vid, "UCs", via_search=True)
    _video(db, "followed", "UCfollowed", via_search=True)
    _video(db, "organic", "UCs")
    ids = ["loose", "watched", "found_by_other", "followed", "organic"]
    search.record_finds(db, user, ids, "cat")
    search.record_finds(db, user, ids, "cat")  # idempotent
    search.record_finds(db, other, ["found_by_other"], "dog")
    reader_service.mark(db, other, "watched", "watched")
    db.commit()
    assert search.clear(db, user, ids) == 1
    db.commit()
    left = set(db.scalars(select(Video.id)))
    assert left == {"watched", "found_by_other", "followed", "organic"}
    assert db.scalars(select(SearchFind.user_id)).all() == [other.id]


def test_a_search_puts_what_the_user_already_has_last(db, make_user):
    user = make_user()
    _channel(db, "UCs")
    _channel(db, "UCmine")
    _sub(db, user, "UCmine")
    for vid, cid in (("new1", "UCs"), ("mine", "UCmine"), ("seen", "UCs"), ("new2", "UCs")):
        _video(db, vid, cid)
    reader_service.mark(db, user, "seen", "hidden")
    db.commit()
    assert search.new_first(db, user, ["mine", "new1", "seen", "new2"]) == [
        "new1",
        "new2",
        "mine",
        "seen",
    ]


# --- what Catalog asks Reader ----------------------------------------------------------------


def test_a_users_tag_links_are_made_once_and_only_theirs_are_read(db, make_user):
    user, other = make_user(), make_user()
    _channel(db)
    mine = reader_service.create_tag(db, user, "Mine", "other", None)
    theirs = reader_service.create_tag(db, other, "Theirs", "other", None)
    reader_service.attach_user_tag(db, user, "UCc", mine.id)
    reader_service.attach_user_tag(db, user, "UCc", mine.id)
    reader_service.attach_user_tag(db, other, "UCc", theirs.id)
    db.commit()
    assert reader_queries.user_tag_links(db, user) == {"UCc": [mine.id]}
    assert reader_queries.user_tag_links(db, user, "UCelse") == {}
    reader_service.detach_user_tag(db, user, "UCc", mine.id)
    db.commit()
    assert reader_queries.user_tag_links(db, user) == {}
    assert reader_queries.user_tag_links(db, other) == {"UCc": [theirs.id]}


def test_discovery_offers_the_playlist_channels_not_followed_and_not_ones_own(db, make_user):
    user = make_user()
    for cid in ("UCnew", "UCfollowed", "UCown"):
        _channel(db, cid)
    for vid, cid in (("n1", "UCnew"), ("n2", "UCnew"), ("f1", "UCfollowed"), ("o1", "UCown")):
        _video(db, vid, cid)
    _sub(db, user, "UCfollowed")
    pl = reader_service.create_playlist(db, user, "L")
    for vid in ("n1", "n2", "f1", "o1"):
        reader_service.add_item(db, pl, vid, mark_dirty=False)
    db.commit()
    rows = reader_queries.playlist_channels(db, user, "UCown", "en")
    assert [(ch.id, n, lists) for ch, n, lists in rows] == [("UCnew", 2, 1)]


def test_an_exploration_older_than_its_grace_is_still_one_row(db, make_user):
    """The grace clock is refreshed in place: re-exploring after the cutoff does not add a row."""
    user = make_user()
    ch = _channel(db)
    db.add(
        ExploredChannel(
            user_id=user.id,
            channel_id="UCc",
            created_at=datetime.now(timezone.utc) - timedelta(days=30),
        )
    )
    db.commit()
    service.explore(db, user, ch)
    db.commit()
    rows = db.scalars(select(ExploredChannel)).all()
    assert len(rows) == 1
    assert rows[0].created_at > datetime.now(timezone.utc) - timedelta(minutes=1)