"""Putting removed Plex playlist rows back WHERE THEY WERE: the list page's "Undo".

A removal can take one row, a season or a whole show, and a season's episodes need not sit together
(a reorder inside the show interleaves them), so each key carries its own index — over the ORDERED
rows, since positions have gaps after a removal. One request: an append plus a second reorder call
leaves the rows at the end whenever that call fails, and would overwrite another tab's changes.
"""

from app.models import PlexItem, PlexLibrary, PlexPlaylist, PlexPlaylistItem


def _seed(db, user, rks, *, positions=None, extra=("x", "y")):
    lib = PlexLibrary(plex_key="p1", title="Movies", kind="movie", enabled=True)
    db.add(lib)
    db.flush()
    items = {}
    for rk in [*rks, *extra]:
        it = PlexItem(rating_key=rk, library_id=lib.id, kind="movie", title=rk.upper())
        db.add(it)
        items[rk] = it
    pl = PlexPlaylist(user_id=user.id, title="L")
    db.add(pl)
    db.flush()
    for i, rk in enumerate(rks):
        pos = (positions or range(99))[i]
        db.add(PlexPlaylistItem(playlist_id=pl.id, item_id=items[rk].id, position=pos))
    db.commit()
    return pl


def _order(db, pid):
    db.expire_all()
    rows = db.execute(
        PlexPlaylistItem.__table__.select()
        .where(PlexPlaylistItem.playlist_id == pid)
        .order_by(PlexPlaylistItem.position, PlexPlaylistItem.id)
    ).all()
    by_id = {it.id: it.rating_key for it in db.query(PlexItem).all()}
    return [by_id[r.item_id] for r in rows], [r.position for r in rows]


def _add(client, pid, keys, positions=None):
    body = {"item_rating_keys": keys}
    if positions is not None:
        body["positions"] = positions
    return client.post(f"/api/plex/playlists/{pid}/items/bulk", json=body)


def test_one_row_goes_back_to_its_index(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a", "b", "c"])
    r = _add(as_user(user), pl.id, ["x"], [1])
    assert r.status_code == 200
    assert r.json()["added"] == 1
    assert _order(db, pl.id) == (["a", "x", "b", "c"], [0, 1, 2, 3])


def test_scattered_rows_go_back_to_each_of_their_indices(db, make_user, as_user):
    # A season whose episodes were interleaved with another season's: removed rows at 1 and 3 of
    # a, x, b, y, c. Given in any order, each lands where it stood.
    user = make_user()
    pl = _seed(db, user, ["a", "b", "c"])
    _add(as_user(user), pl.id, ["y", "x"], [3, 1])
    assert _order(db, pl.id)[0] == ["a", "x", "b", "y", "c"]


def test_indices_count_rows_not_stored_numbers(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a", "b", "c"], positions=[0, 7, 20])
    _add(as_user(user), pl.id, ["x"], [2])
    assert _order(db, pl.id) == (["a", "b", "x", "c"], [0, 1, 2, 3])


def test_an_index_past_the_end_appends(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a"])
    _add(as_user(user), pl.id, ["x"], [50])
    assert _order(db, pl.id)[0] == ["a", "x"]


def test_a_row_already_in_the_list_does_not_move(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a", "b", "c"])
    r = _add(as_user(user), pl.id, ["c"], [0])
    assert r.json()["added"] == 0
    assert _order(db, pl.id)[0] == ["a", "b", "c"]


def test_without_positions_it_still_appends(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a", "b"])
    _add(as_user(user), pl.id, ["y", "x"])
    assert _order(db, pl.id)[0] == ["a", "b", "y", "x"]


def test_positions_must_pair_with_the_keys(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a"])
    assert _add(as_user(user), pl.id, ["x", "y"], [0]).status_code == 422
    assert _add(as_user(user), pl.id, ["x"], [-1]).status_code == 422
    assert _order(db, pl.id)[0] == ["a"]


def test_remove_then_put_back_is_no_change(db, make_user, as_user):
    user = make_user()
    pl = _seed(db, user, ["a", "b", "c", "d"], extra=())
    client = as_user(user)
    assert (
        client.post(
            f"/api/plex/playlists/{pl.id}/items/remove-bulk", json={"item_rating_keys": ["b", "d"]}
        ).status_code
        == 200
    )
    assert _order(db, pl.id)[0] == ["a", "c"]
    _add(client, pl.id, ["b", "d"], [1, 3])
    assert _order(db, pl.id)[0] == ["a", "b", "c", "d"]