"""V0: DeadlineScheduler — ordering, cancellation, early-wake, jitter."""

from __future__ import annotations

import asyncio
import random
import sys

sys.path.insert(0, "/mnt/dolphinng5_predict")

import pytest

from prod.clean_arch.violet.clock import DeadlineScheduler, LatencyHistogram, mono_ns


@pytest.mark.asyncio
async def test_deadlines_fire_in_due_order_after_shuffled_insert():
    fired: list[int] = []
    sched = DeadlineScheduler()
    sched.start()
    base = mono_ns()
    order = list(range(1_000))
    random.Random(7).shuffle(order)
    for k in order:
        due = base + (k + 1) * 1_000_000  # 1ms apart, shuffled insertion
        sched.schedule_at(due, (lambda kk=k: fired.append(kk)))
    await asyncio.sleep(1.3)
    await sched.stop()
    assert len(fired) == 1_000
    assert fired == sorted(fired)


@pytest.mark.asyncio
async def test_cancellation_prevents_fire():
    fired: list[str] = []
    sched = DeadlineScheduler()
    sched.start()
    keep = sched.schedule_in(30, lambda: fired.append("keep"))
    kill = sched.schedule_in(30, lambda: fired.append("kill"))
    kill.cancel()
    await asyncio.sleep(0.12)
    await sched.stop()
    assert fired == ["keep"]
    assert kill.cancelled and not kill.fired
    assert keep.fired


@pytest.mark.asyncio
async def test_early_wake_on_earlier_insert():
    """A deadline inserted BELOW the current head must fire on time even when
    the driver was sleeping toward a much later head — the early-wake path."""
    sched = DeadlineScheduler(max_sleep_ms=5_000)  # tick alone would be too slow
    jit = LatencyHistogram("j")
    sched.jitter_hist = jit
    sched.start()
    fired_at: list[int] = []
    sched.schedule_in(4_000, lambda: None)              # far head; driver sleeps
    await asyncio.sleep(0.05)                            # driver now parked
    due = mono_ns() + 20_000_000                         # 20ms from now
    sched.schedule_at(due, lambda: fired_at.append(mono_ns()))
    await asyncio.sleep(0.15)
    await sched.stop()
    assert fired_at, "early deadline never fired — early-wake broken"
    lateness_ms = (fired_at[0] - due) / 1e6
    assert lateness_ms < 25.0, f"early-wake too late: {lateness_ms:.1f}ms"


@pytest.mark.asyncio
async def test_no_early_fires_and_jitter_budget_under_cpu_noise():
    jit = LatencyHistogram("jitter")
    sched = DeadlineScheduler(jitter_hist=jit)
    sched.start()
    early = [0]
    rng = random.Random(11)
    dues = []
    for _ in range(400):
        due = mono_ns() + int(rng.uniform(10, 800) * 1e6)
        dues.append(due)
        sched.schedule_at(due, (lambda d=due: early.__setitem__(0, early[0] + 1) if mono_ns() < d else None))

    async def cpu_noise():
        end = mono_ns() + int(0.9e9)
        while mono_ns() < end:
            sum(i * i for i in range(2_000))
            await asyncio.sleep(0)

    noise = asyncio.create_task(cpu_noise())
    await asyncio.sleep(1.0)
    noise.cancel()
    await sched.stop()
    assert early[0] == 0, "deadline fired EARLY"
    assert sched.fired_count == 400
    p99_ms = jit.percentile_ns(0.99) / 1e6
    assert p99_ms < 25.0, f"jitter p99 {p99_ms:.2f}ms exceeds 25ms budget"


@pytest.mark.asyncio
async def test_callback_exception_does_not_kill_driver():
    errors: list[str] = []
    sched = DeadlineScheduler(on_error=lambda dl, e: errors.append(str(e)))
    sched.start()
    fired: list[str] = []
    sched.schedule_in(10, lambda: (_ for _ in ()).throw(RuntimeError("boom")))
    sched.schedule_in(40, lambda: fired.append("after"))
    await asyncio.sleep(0.12)
    await sched.stop()
    assert errors and "boom" in errors[0]
    assert fired == ["after"], "driver died after callback exception"


if __name__ == "__main__":
    raise SystemExit(pytest.main([__file__, "-v"]))