from __future__ import annotations

from datetime import UTC, datetime, timedelta

from trex_core.application.balance_health import BalanceHealthTracker


def test_long_outage_backoff_is_capped_and_status_stays_valid():
    now = {"t": datetime(2026, 9, 12, tzinfo=UTC)}
    tracker = BalanceHealthTracker(clock=lambda: now["t"], base_backoff_sec=15, max_backoff_sec=300)

    backoffs: list[float] = []
    for _ in range(20):
        lifecycle, backoff = tracker.record_failure("execution", code="http_5xx")
        backoffs.append(backoff)
        assert lifecycle in {None, "detected", "ongoing"}
        now["t"] += timedelta(seconds=301)

    assert max(backoffs) == 300.0
    state = tracker.status("execution", stale_after_sec=600)
    assert state["state"] == "unavailable"
    assert state["consecutive_failures"] == 20
    assert state["failure_code"] == "http_5xx"


def test_long_outage_over_1100_failures_never_overflows_and_stays_capped():
    now = {"t": datetime(2026, 9, 12, tzinfo=UTC)}
    tracker = BalanceHealthTracker(clock=lambda: now["t"], base_backoff_sec=15, max_backoff_sec=300)

    last_lifecycle = None
    for i in range(1_100):
        lifecycle, backoff = tracker.record_failure("execution", code="http_5xx")
        last_lifecycle = lifecycle
        if i >= 5:
            assert backoff == 300.0
        else:
            assert backoff <= 300.0
        now["t"] += timedelta(seconds=301)

    state = tracker.status("execution", stale_after_sec=600)
    assert state["state"] == "unavailable"
    assert state["consecutive_failures"] == 1_100
    assert state["failure_code"] == "http_5xx"
    assert state["next_retry_at"] is not None
    assert last_lifecycle in {None, "ongoing"}


def test_restart_resets_process_local_health_and_re_emits_detected():
    now = {"t": datetime(2026, 9, 12, tzinfo=UTC)}
    before_restart = BalanceHealthTracker(clock=lambda: now["t"])
    before_restart.record_success("execution")
    lifecycle, _ = before_restart.record_failure("execution", code="timeout")
    assert lifecycle == "detected"

    after_restart = BalanceHealthTracker(clock=lambda: now["t"])
    lifecycle, _ = after_restart.record_failure("execution", code="timeout")
    assert lifecycle == "detected"
    state = after_restart.status("execution", stale_after_sec=600)
    assert state["last_success_at"] is None
    assert state["consecutive_failures"] == 1