"""Migration 0113 (#4431): images linked to a post before its date arrived get
the post's date back. Runs the migration's data step against real rows."""
import importlib.util
from datetime import UTC, datetime
from pathlib import Path

import pytest

from backend.app.models import Artist, ImageProvenance, ImageRecord, Post
from tests.factories import make_image as _img

pytestmark = pytest.mark.integration

_MIGRATION = (
    Path(__file__).resolve().parents[1]
    / "alembic" / "versions" / "0113_redate_native_images.py"
)


def _redate():
    spec = importlib.util.spec_from_file_location("m0113", _MIGRATION)
    mod = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(mod)
    return mod.redate_images


def _post(db, artist, epid, when):
    p = Post(artist_id=artist.id, external_post_id=epid, post_date=when)
    db.add(p)
    db.flush()
    return p


def _link(db, img, post, *, primary):
    db.add(ImageProvenance(image_record_id=img.id, post_id=post.id))
    if primary:
        img.primary_post_id = post.id
    db.flush()


def test_redate_images_from_their_posts(db_sync):
    sent = datetime(2024, 3, 1, 18, 30, tzinfo=UTC)
    earlier = datetime(2023, 1, 5, tzinfo=UTC)
    artist = Artist(name="Alice", slug="alice")
    db_sync.add(artist)
    db_sync.flush()
    undated = _post(db_sync, artist, "u1", None)
    dated = _post(db_sync, artist, "d1", sent)
    repost = _post(db_sync, artist, "r1", earlier)

    stale = _img(db_sync, "a" * 64)          # primary post dated, image not
    reposted = _img(db_sync, "b" * 64)       # also in an earlier post
    orphan = _img(db_sync, "c" * 64)         # only an undated post
    _link(db_sync, stale, dated, primary=True)
    _link(db_sync, reposted, dated, primary=True)
    _link(db_sync, reposted, repost, primary=False)
    _link(db_sync, orphan, undated, primary=True)
    orphan_before = orphan.effective_date

    _redate()(db_sync.connection())
    db_sync.expire_all()

    stale = db_sync.get(ImageRecord, stale.id)
    reposted = db_sync.get(ImageRecord, reposted.id)
    orphan = db_sync.get(ImageRecord, orphan.id)
    assert stale.effective_date == sent
    assert stale.earliest_post_date == sent
    assert reposted.effective_date == sent             # the primary post's date
    assert reposted.earliest_post_date == earlier      # the earliest post's date
    assert orphan.effective_date == orphan_before      # no date to take