groups:
  - name: polyweather-runtime
    rules:
      - alert: PolyWeatherWebDown
        expr: up{job="polyweather-web"} == 0
        for: 2m
        labels:
          severity: critical
        annotations:
          summary: "PolyWeather web metrics endpoint is down"
          description: "/metrics on polyweather_web has been unreachable for more than 2 minutes."

      - alert: PolyWeatherHttp5xxBurst
        expr: sum(increase(polyweather_http_requests_total{status=~"5.."}[10m])) > 10
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "PolyWeather HTTP 5xx burst"
          description: "More than 10 server errors were observed in the last 10 minutes."

      - alert: PolyWeatherHighSourceErrorRate
        expr: |
          (
            sum(increase(polyweather_source_requests_total{outcome!~"success|cache_hit"}[15m]))
            /
            clamp_min(sum(increase(polyweather_source_requests_total[15m])), 1)
          ) > 0.25
          and sum(increase(polyweather_source_requests_total[15m])) > 20
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "PolyWeather source error rate is high"
          description: "External weather source errors exceeded 25% over the last 15 minutes."

      - alert: PolyWeatherOpenMeteoCooldownLoop
        expr: sum(increase(polyweather_source_requests_total{source="open_meteo",outcome=~"cooldown_skip|error"}[15m])) > 20
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "Open-Meteo is rate-limited or erroring"
          description: "Open-Meteo has produced repeated cooldown skips or errors in the last 15 minutes."

      - alert: PolyWeatherSlowHttpAverage
        expr: |
          (
            sum(rate(polyweather_http_request_duration_ms_sum[10m]))
            /
            clamp_min(sum(rate(polyweather_http_request_duration_ms_count[10m])), 1)
          ) > 2000
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "PolyWeather average HTTP latency is high"
          description: "Average HTTP request duration exceeded 2s over the last 10 minutes."