"""create_notification title-clamp regression.

A downloaded FB/IG reel's "title" is the whole caption (hundreds to ~1900 chars). Before the
clamp that string went straight into Notification.title (String(255)) and, at the batched
download_gc commit, raised psycopg StringDataRightTruncation — aborting the entire GC run so
no expiry deletion / LRU eviction / orphan reap ever ran. The clamp trims the title to the
column limit centrally, defending all callers regardless of DB backend."""
from app.models import Notification, User
from app.notifications import TITLE_MAX_LEN, create_notification


class _CaptureDB:
    """Captures the added row without a real DB, so the clamp is verified on every lane
    (the truncation only reproduces on Postgres; the clamp logic is backend-agnostic)."""

    def __init__(self):
        self.added: list[Notification] = []

    def add(self, obj):
        self.added.append(obj)

    def commit(self):
        pass

    def refresh(self, _obj):
        pass


def test_title_clamped_to_column_limit():
    long_title = "x" * 2000  # e.g. a reel caption
    notif = create_notification(
        _CaptureDB(), user_id=1, type="download_expiring", title=long_title
    )
    assert len(notif.title) == TITLE_MAX_LEN
    assert notif.title.endswith("…")
    # The untruncated title still reaches the client via `data`, which is never clamped.
    notif2 = create_notification(
        _CaptureDB(),
        user_id=1,
        type="download_expiring",
        title=long_title,
        data={"kind": "download_expiring", "title": long_title},
    )
    assert notif2.data["title"] == long_title


def test_short_title_is_untouched():
    notif = create_notification(_CaptureDB(), user_id=1, type="t", title="short")
    assert notif.title == "short"


def test_title_at_exactly_the_limit_is_untouched():
    exact = "y" * TITLE_MAX_LEN
    notif = create_notification(_CaptureDB(), user_id=1, type="t", title=exact)
    assert notif.title == exact


def test_limit_tracks_the_actual_column_width():
    # The clamp is derived from the model, so it can't silently drift from the column a
    # migration would change (which is exactly what re-introduces the truncation bug).
    assert TITLE_MAX_LEN == Notification.__table__.c.title.type.length


def test_over_long_title_actually_commits_on_postgres(db):
    # The stub tests above prove the clamp *logic*; this proves the real fix end-to-end —
    # a caption-length title now COMMITS into varchar(TITLE_MAX_LEN) instead of raising
    # StringDataRightTruncation. Uses the opt-in Postgres lane (skipped with no DB).
    user = User(email="reel@example.com")
    db.add(user)
    db.flush()
    notif = create_notification(
        db, user_id=user.id, type="download_expiring", title="z" * 2000
    )
    db.refresh(notif)
    assert len(notif.title) == TITLE_MAX_LEN  # persisted, not truncated by the DB