from __future__ import annotations

import pytest
from backup_tool.execution import TransitionError, transition


@pytest.mark.parametrize(
    ("current", "target"),
    [
        ("queued", "preparing"),
        ("queued", "cancelled"),
        ("queued", "failed"),
        ("preparing", "running"),
        ("preparing", "cancelling"),
        ("preparing", "failed"),
        ("running", "verifying"),
        ("running", "cancelling"),
        ("running", "failed"),
        ("verifying", "committed"),
        ("verifying", "failed"),
        ("cancelling", "cancelled"),
        ("cancelling", "failed"),
    ],
)
def test_all_legal_execution_transitions_are_accepted(current: str, target: str) -> None:
    assert transition(current, target) == target


@pytest.mark.parametrize(
    ("current", "target"),
    [
        ("queued", "running"),
        ("preparing", "queued"),
        ("running", "preparing"),
        ("verifying", "cancelling"),
        ("cancelling", "running"),
        ("committed", "cancelled"),
        ("cancelled", "queued"),
        ("failed", "queued"),
        ("unknown", "queued"),
    ],
)
def test_invalid_or_backward_execution_transitions_are_rejected(current: str, target: str) -> None:
    with pytest.raises(TransitionError) as raised:
        transition(current, target)

    assert raised.value.code == "invalid_transition"