"""G8 -- nightmare mode degrades but does not collapse."""
import random
import time

import pytest

from harness.config import GATEWAY_URL
from harness.load import drive

pytestmark = pytest.mark.pathology


async def test_nightmare_degrades_but_survives(chaos, manifest, api):
    """G8: same driver, chaos-clean then chaos-nightmare, 300 requests at
    concurrency 20 each. Nightmare p95 >= 5x clean p95; nightmare error rate
    in [2%, 15%]; >= 80% of requests still return a valid envelope (success or
    a structured error, never a connection reset or empty body);
    GET /api/health/all still responds within 5s during the burst."""
    accounts = manifest["cold_account_ids_sample"] + manifest["hot_account_ids"]

    def url_factory():
        account_id = random.choice(accounts)
        return (f"{GATEWAY_URL}/api/accounts/{account_id}/insights", {})

    await chaos.set_profile("clean")
    clean_report = await drive("GET", url_factory, total=300, concurrency=20, warmup=20)

    await chaos.set_profile("nightmare")
    nightmare_report = await drive("GET", url_factory, total=300, concurrency=20, warmup=20)

    assert nightmare_report.p95 >= 5 * clean_report.p95, (
        f"nightmare p95 not >= 5x clean p95\nclean={clean_report}\nnightmare={nightmare_report}"
    )
    assert 0.02 <= nightmare_report.error_rate <= 0.15, str(nightmare_report)

    valid_requests = nightmare_report.count - nightmare_report.exceptions
    valid_share = valid_requests / nightmare_report.count
    assert valid_share >= 0.80, (
        f"only {valid_requests}/{nightmare_report.count} requests returned a "
        f"valid envelope (no reset/empty body): {nightmare_report}"
    )

    start = time.perf_counter()
    resp = await api.get("/api/health/all")
    elapsed = time.perf_counter() - start
    assert elapsed < 5, f"/api/health/all took {elapsed:.2f}s during the nightmare burst"
    assert resp.status_code == 200