"""Integration: the newest Traefik row per router, read by walking the
(router_name, scraped_at) index rather than grouping every row (#5254).
Requires STEWARD_DATABASE_URL."""
from __future__ import annotations

import asyncio
import os
import uuid
from datetime import datetime, timedelta, timezone

import pytest

pytestmark = pytest.mark.integration


@pytest.fixture
def app():
    if not os.environ.get("STEWARD_DATABASE_URL"):
        pytest.skip("needs Postgres")
    from steward.app import create_app
    return create_app(testing=False)


def test_each_router_reads_as_its_newest_row(app):
    from plugins.traefik.models import TraefikMetric
    from plugins.traefik.routes import latest_per_router

    now = datetime.now(timezone.utc).replace(microsecond=0)
    tag = uuid.uuid4().hex[:8]
    a, b = f"a-{tag}@docker", f"b-{tag}@docker"

    def row(name, ago, rate):
        return TraefikMetric(router_name=name, scraped_at=now - timedelta(minutes=ago), request_rate=rate,
                             error_rate_4xx_pct=0.0, error_rate_5xx_pct=0.0, latency_p50_ms=1.0,
                             latency_p95_ms=2.0, latency_p99_ms=3.0, response_bytes_rate=0.0)

    async def go():
        async with app.db_sessionmaker() as s:
            async with s.begin():
                s.add_all([row(a, 3, 1.0), row(a, 1, 2.0), row(a, 2, 3.0), row(b, 5, 4.0)])
            async with s.begin():
                return {m.router_name: m for m in await latest_per_router(s)}

    got = asyncio.run(go())
    assert got[a].request_rate == 2.0 and got[a].scraped_at == now - timedelta(minutes=1)
    assert got[b].request_rate == 4.0