"""Tests for the pure SessionTracker module (no fakes, no I/O)."""

from stt_daemon.session import SessionTracker


def _counter():
    """Deterministic id factory: returns id-1, id-2, ... and records call times."""
    calls = []

    def factory(now):
        calls.append(now)
        return f"id-{len(calls)}"

    return factory, calls


def test_current_id_is_none_before_first_observe():
    factory, _ = _counter()
    tracker = SessionTracker(300.0, factory)

    assert tracker.current_id is None


def test_first_observe_mints_the_factory_id_for_now():
    def factory(now):
        return f"id-{now}"

    tracker = SessionTracker(300.0, factory)

    assert tracker.observe(100.0) == factory(100.0)


def test_same_id_within_gap_then_new_id_beyond_gap():
    gap = 1.0
    factory, calls = _counter()
    tracker = SessionTracker(gap, factory)

    first = tracker.observe(100.0)
    # `gap - 1` after the first observation: still inside the gap, same id.
    assert tracker.observe(100.0 + gap - 1) == first
    # Beyond the gap: a new id, and the factory minted exactly twice.
    assert tracker.observe(100.0 + gap + 1) != first
    assert len(calls) == 2


def test_exact_gap_boundary_does_not_mint():
    gap = 300.0
    factory, calls = _counter()
    tracker = SessionTracker(gap, factory)

    first = tracker.observe(100.0)
    # now - last == gap is NOT > gap, so the boundary must not roll over.
    assert tracker.observe(100.0 + gap) == first
    assert len(calls) == 1


def test_just_beyond_gap_mints_a_new_id():
    gap = 300.0
    factory, calls = _counter()
    tracker = SessionTracker(gap, factory)

    first = tracker.observe(100.0)
    assert tracker.observe(100.0 + gap + 1) != first
    assert len(calls) == 2


def test_zero_gap_returns_one_id_forever():
    factory, calls = _counter()
    tracker = SessionTracker(0.0, factory)

    first = tracker.observe(0.0)
    assert tracker.observe(1_000_000.0) == first
    assert tracker.observe(1_000_000_000.0) == first
    assert len(calls) == 1


def test_negative_gap_also_disables_rollover():
    factory, calls = _counter()
    tracker = SessionTracker(-5.0, factory)

    first = tracker.observe(100.0)
    assert tracker.observe(100.0 + 86_400.0) == first
    assert len(calls) == 1


def test_large_jump_yields_exactly_one_new_id():
    gap = 300.0
    factory, calls = _counter()
    tracker = SessionTracker(gap, factory)

    first = tracker.observe(100.0)
    after = tracker.observe(100.0 + 86_400.0)

    assert after != first
    assert len(calls) == 2


def test_current_id_tracks_the_latest_minted_id():
    factory, _ = _counter()
    tracker = SessionTracker(300.0, factory)

    assert tracker.current_id is None
    first = tracker.observe(100.0)
    assert tracker.current_id == first
    rolled = tracker.observe(100.0 + 301)
    assert tracker.current_id == rolled