"""Unit-Tests stabile IDs (PLAN.md §3.6, §6.3)."""

from __future__ import annotations

import uuid

from hms_domain import new_node_id, new_uuid, persistent_node_id


def test_new_uuids_are_unique_and_parseable() -> None:
    a, b = new_uuid(), new_uuid()
    assert a != b
    uuid.UUID(a)
    uuid.UUID(b)


def test_node_id_is_uuid_and_random() -> None:
    a, b = new_node_id(), new_node_id()
    uuid.UUID(a)
    assert a != b


def test_persistent_node_id_stable_across_calls(tmp_path) -> None:
    identity = tmp_path / "identity" / "node_id"
    first = persistent_node_id(identity)
    second = persistent_node_id(identity)
    assert first == second  # IP-/Hostnamenunabhängig: Datei ist Quelle der Wahrheit
    assert identity.read_text(encoding="utf-8").strip() == first


def test_persistent_node_id_validated_on_load(tmp_path) -> None:
    identity = tmp_path / "identity" / "node_id"
    identity.parent.mkdir(parents=True)
    identity.write_text("not-a-uuid", encoding="utf-8")
    import pytest

    with pytest.raises(ValueError):
        persistent_node_id(identity)


def test_two_nodes_get_distinct_ids(tmp_path) -> None:
    a = persistent_node_id(tmp_path / "a" / "node_id")
    b = persistent_node_id(tmp_path / "b" / "node_id")
    assert a != b  # doppelte node_ids wären ein Fehler (§6.3)


def test_concurrent_creation_yields_single_id(tmp_path) -> None:
    """O_EXCL-Rennbedingung: beide Aufrufer erhalten dieselbe ID."""
    identity = tmp_path / "identity" / "node_id"
    id_a = persistent_node_id(identity)
    # zweite Erzeugung mit bereits existierender Datei → lädt vorhandene ID
    id_b = persistent_node_id(identity)
    assert id_a == id_b