import importlib.util
from pathlib import Path

import pytest

spec = importlib.util.spec_from_file_location(
    "migration_worker_gate",
    Path(__file__).resolve().parents[2] / "scripts/migration_worker_gate.py",
)
gate = importlib.util.module_from_spec(spec)
spec.loader.exec_module(gate)


@pytest.mark.parametrize("role", ["worker", "scheduler"])
def test_hold_prevents_outbound_process_until_release(role):
    states = iter([True, True, False])
    events = []
    gate.start(
        role,
        check=lambda: next(states),
        sleep=lambda seconds: events.append("wait"),
        execute=lambda executable, args: events.append(args),
    )
    assert events == ["wait", "wait", gate.COMMANDS[role]]


def test_normal_startup_and_missing_hold(tmp_path):
    assert not gate.hold_active(tmp_path / "absent")
    events = []
    gate.start("worker", check=lambda: False, execute=lambda executable, args: events.append(args))
    assert events == [gate.COMMANDS["worker"]]


def test_hold_exists_and_unsupported_marker_fails_closed(tmp_path):
    marker = tmp_path / "hold"
    marker.write_text("fixture-attempt")
    assert gate.hold_active(marker)
    with pytest.raises(RuntimeError):
        gate.hold_active(tmp_path)


def test_unknown_role_never_executes():
    with pytest.raises(ValueError):
        gate.start("shell", execute=lambda *args: pytest.fail("unreviewed command"))