from datetime import datetime, timedelta, timezone

from fastapi.testclient import TestClient
from sqlmodel import Session

from app.core.config import settings
from app.models import EngineEvent, FlowRun, MetricBucket

PREFIX = f"{settings.API_V1_STR}/observability"
FLOW = "observability-test"


def _seed(db: Session) -> None:
    now = datetime.now(timezone.utc).replace(second=0, microsecond=0)
    db.add(
        MetricBucket(
            flow=FLOW,
            node=f"{FLOW}.calc",
            bucket=now - timedelta(minutes=1),
            executions=4,
            errors=1,
            messages=6,
            duration_sum_ms=40.0,
            duration_max_ms=25.0,
            lag_sum_ms=100.0,
            lag_max_ms=60.0,
            items=4,
        )
    )
    db.add(
        EngineEvent(
            ts=now,
            type="node_error",
            flow=FLOW,
            node=f"{FLOW}.calc",
            detail="ValueError: bad input\nTraceback",
        )
    )
    db.add(
        EngineEvent(
            ts=now, type="audit", flow=FLOW, detail="published", actor="a@example.com"
        )
    )
    db.add(
        FlowRun(
            id="9-0",
            flow=FLOW,
            source="external",
            started_at=now,
            finished_at=now,
            status="ok",
            nodes=3,
            duration_ms=12.5,
        )
    )
    db.commit()


def test_observability_requires_authentication(client: TestClient) -> None:
    assert client.get(f"{PREFIX}/summary").status_code == 401


def test_the_summary_answers_even_when_degraded(
    client: TestClient, superuser_token_headers: dict[str, str]
) -> None:
    response = client.get(f"{PREFIX}/summary", headers=superuser_token_headers)

    assert response.status_code == 200
    body = response.json()
    assert body["status"] in {"ok", "degraded"}
    assert set(body["flows"]) == {"total", "running", "paused", "quarantined"}
    assert "error" in body["nodes"]


def test_the_history_reads_back(
    client: TestClient, superuser_token_headers: dict[str, str], db: Session
) -> None:
    _seed(db)

    points = client.get(f"{PREFIX}/timeseries", headers=superuser_token_headers).json()
    mine = [point for point in points if point["executions"]]
    assert mine and mine[-1]["avg_ms"] > 0

    flows = client.get(f"{PREFIX}/flows", headers=superuser_token_headers).json()
    row = next(entry for entry in flows if entry["flow"] == FLOW)
    assert (row["executions"], row["errors"], row["messages"]) == (4, 1, 6)
    assert len(row["spark"]) == 60
    assert row["last_error_ts"] is not None

    runs = client.get(f"{PREFIX}/runs", headers=superuser_token_headers).json()
    assert any(run["id"] == "9-0" and run["status"] == "ok" for run in runs)

    failures = client.get(f"{PREFIX}/events", headers=superuser_token_headers).json()
    assert any("Traceback" in event["detail"] for event in failures)
    assert all(event["type"] != "audit" for event in failures)

    audit = client.get(
        f"{PREFIX}/events", headers=superuser_token_headers, params={"kind": "audit"}
    ).json()
    assert any(event["actor"] == "a@example.com" for event in audit)

    dead = client.get(f"{PREFIX}/dead-letter", headers=superuser_token_headers)
    assert dead.status_code == 200
    assert isinstance(dead.json(), list)


def test_runs_narrow_to_one_minute(
    client: TestClient, superuser_token_headers: dict[str, str], db: Session
) -> None:
    """A minute picked off a chart reaches past what the recent list holds."""
    minute = datetime.now(timezone.utc).replace(second=0, microsecond=0) - timedelta(
        hours=3
    )
    db.add(FlowRun(id="minute-in", flow=FLOW, started_at=minute, status="ok"))
    db.add(
        FlowRun(
            id="minute-after",
            flow=FLOW,
            started_at=minute + timedelta(minutes=1),
            status="ok",
        )
    )
    db.commit()

    runs = client.get(
        f"{PREFIX}/runs",
        headers=superuser_token_headers,
        params={
            "since": minute.isoformat(),
            "until": (minute + timedelta(minutes=1)).isoformat(),
        },
    ).json()

    # The upper bound is exclusive, so the run starting the next minute is not
    # in this one.
    assert [run["id"] for run in runs] == ["minute-in"]