"""Lock acquisition ordering (deadlock prevention)."""

import pytest

from photo_pipeline.jobs import locks


def test_broad_to_narrow_ranks():
    assert locks.rank("library") < locks.rank("rename")
    assert locks.rank("rename") < locks.rank("album")
    assert locks.rank("album") < locks.rank("asset")


def test_acquiring_narrower_while_holding_broader_is_allowed():
    locks.validate_acquisition(["library"], "asset")  # no raise
    locks.validate_acquisition(["library", "album"], "asset")


def test_acquiring_broader_while_holding_narrower_is_rejected():
    with pytest.raises(locks.LockOrderError):
        locks.validate_acquisition(["asset"], "library")
    with pytest.raises(locks.LockOrderError):
        locks.validate_acquisition(["album"], "rename")


def test_unknown_lock_is_rejected():
    with pytest.raises(locks.LockOrderError):
        locks.rank("nonsense")