"""Protect the monitoring backend from known query-starvation regressions."""

from pathlib import Path

import yaml


REPO_ROOT = Path(__file__).resolve().parents[2]


def _documents(path: Path) -> list[dict]:
    """Load every non-empty YAML document from a repository manifest."""
    return [document for document in yaml.safe_load_all(path.read_text()) if document]


def test_victoria_metrics_has_dashboard_burst_headroom() -> None:
    """Keep search capacity and pod resources above the proven failure floor."""
    manifests = _documents(REPO_ROOT / "services/monitoring/helmrelease.yaml")
    release = next(
        manifest
        for manifest in manifests
        if manifest.get("kind") == "HelmRelease"
        and manifest.get("metadata", {}).get("name") == "victoria-metrics-single"
    )
    server = release["spec"]["values"]["server"]

    assert int(server["extraArgs"]["search.maxConcurrentRequests"]) >= 4
    assert server["extraArgs"]["search.maxQueryDuration"] == "1m"
    assert server["extraArgs"]["search.maxQueueDuration"] == "30s"
    assert server["resources"]["requests"]["memory"] == "2Gi"
    assert server["resources"]["limits"]["cpu"] == "2"
    assert server["resources"]["limits"]["memory"] == "4Gi"

    required_terms = server["affinity"]["nodeAffinity"][
        "requiredDuringSchedulingIgnoredDuringExecution"
    ]["nodeSelectorTerms"]
    hostname_rule = next(
        expression
        for term in required_terms
        for expression in term["matchExpressions"]
        if expression["key"] == "kubernetes.io/hostname"
    )
    assert hostname_rule["operator"] == "NotIn"
    assert {"titan-14", "titan-18"} <= set(hostname_rule["values"])


def test_yearly_availability_reuses_the_hourly_rollup() -> None:
    """Prevent the yearly rule from rescanning raw cluster metrics for 365 days."""
    manifest = _documents(
        REPO_ROOT / "services/monitoring/vmalert-atlas-availability.yaml"
    )[0]
    groups = yaml.safe_load(manifest["data"]["atlas-availability.yaml"])["groups"]
    rules = [rule for group in groups for rule in group["rules"]]
    yearly = next(
        rule
        for rule in rules
        if rule["record"] == "atlas:availability:ratio_365d"
    )

    assert "atlas:availability:gateway_requests_1h" in yearly["expr"]
    assert "atlas:availability:gateway_failures_1h" in yearly["expr"]
    assert 'definition="gateway-v3"' in yearly["expr"]
    assert "sum_over_time" in yearly["expr"]
    assert "[365d]" in yearly["expr"]
    assert "traefik_entrypoint_requests_total" not in yearly["expr"]
    assert yearly["labels"]["definition"] == "gateway-v3"


def test_availability_uses_gateway_failures_instead_of_replica_capacity() -> None:
    """Measure request outcomes without treating redundant replica loss as downtime."""
    manifest = _documents(
        REPO_ROOT / "services/monitoring/vmalert-atlas-availability.yaml"
    )[0]
    groups = yaml.safe_load(manifest["data"]["atlas-availability.yaml"])["groups"]
    rules = [rule for group in groups for rule in group["rules"]]
    requests = next(
        rule
        for rule in rules
        if rule["record"] == "atlas:availability:gateway_requests_1h"
    )
    failures = next(
        rule
        for rule in rules
        if rule["record"] == "atlas:availability:gateway_failures_1h"
    )

    assert 'code=~"[1-5].."' in requests["expr"]
    assert 'code=~"502|503|504"' in failures["expr"]
    assert "traefik_entrypoint_requests_total" in requests["expr"]
    assert "traefik_entrypoint_requests_total" in failures["expr"]
    assert "kube_node_status_condition" not in repr(rules)
    assert "kube_deployment_status_replicas_available" not in repr(rules)
    assert requests["labels"]["definition"] == "gateway-v3"
    assert failures["labels"]["definition"] == "gateway-v3"


def test_availability_backfill_replays_the_same_gateway_sli() -> None:
    """Backfill retained history with the exact rules used for future samples."""
    manifests = _documents(
        REPO_ROOT / "services/monitoring/availability-backfill-v3-job.yaml"
    )
    config = next(manifest for manifest in manifests if manifest["kind"] == "ConfigMap")
    job = next(manifest for manifest in manifests if manifest["kind"] == "Job")
    backfill = yaml.safe_load(config["data"]["atlas-gateway-history.yaml"])
    expressions = {
        rule["record"]: rule["expr"]
        for group in backfill["groups"]
        for rule in group["rules"]
    }

    assert 'code=~"[1-5].."' in expressions["atlas:availability:gateway_requests_1h"]
    assert 'code=~"502|503|504"' in expressions["atlas:availability:gateway_failures_1h"]
    args = job["spec"]["template"]["spec"]["containers"][0]["args"]
    assert "-replay.timeFrom=2026-05-01T00:00:00Z" in args
    assert "-replay.timeTo=2026-08-04T23:00:00Z" in args
    assert "-replay.maxDatapointsPerQuery=48" in args


def test_quality_rollups_do_not_run_every_minute() -> None:
    """Keep high-cardinality quality rollups below the backend saturation cadence."""
    manifest = _documents(
        REPO_ROOT / "services/monitoring/vmalert-atlas-availability.yaml"
    )[0]
    quality = yaml.safe_load(manifest["data"]["platform-quality.yaml"])["groups"][0]

    assert quality["interval"] == "5m"


def test_vmalert_reloads_updated_rule_files() -> None:
    """Make Flux ConfigMap updates take effect without manual pod revision bumps."""
    manifests = _documents(
        REPO_ROOT / "services/monitoring/vmalert-atlas-availability.yaml"
    )
    deployment = next(
        manifest for manifest in manifests if manifest.get("kind") == "Deployment"
    )
    args = deployment["spec"]["template"]["spec"]["containers"][0]["args"]

    assert "-configCheckInterval=30s" in args