summarise data from openmeteo

cmd/ingestd/forecast_logging.go

@@ -0,0 +1,219 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"math"
+	"strings"
+	"sync"
+	"time"
+
+	"go-weatherstation/internal/mqttingest"
+	"go-weatherstation/internal/providers"
+)
+
+type ForecastCache struct {
+	mu  sync.RWMutex
+	res *providers.ForecastResult
+}
+
+func (c *ForecastCache) Set(res *providers.ForecastResult) {
+	if c == nil {
+		return
+	}
+	c.mu.Lock()
+	c.res = copyForecast(res)
+	c.mu.Unlock()
+}
+
+func (c *ForecastCache) Get() *providers.ForecastResult {
+	if c == nil {
+		return nil
+	}
+	c.mu.RLock()
+	res := c.res
+	c.mu.RUnlock()
+	return res
+}
+
+func copyForecast(res *providers.ForecastResult) *providers.ForecastResult {
+	if res == nil {
+		return nil
+	}
+	out := &providers.ForecastResult{
+		RetrievedAt: res.RetrievedAt,
+		Model:       res.Model,
+	}
+	if len(res.Hourly) > 0 {
+		out.Hourly = make([]providers.HourlyForecastPoint, len(res.Hourly))
+		copy(out.Hourly, res.Hourly)
+	}
+	return out
+}
+
+func forecastSummary(res *providers.ForecastResult) string {
+	if res == nil || len(res.Hourly) == 0 {
+		return ""
+	}
+
+	start := res.Hourly[0].TS
+	end := res.Hourly[len(res.Hourly)-1].TS
+	parts := []string{
+		fmt.Sprintf("range=%s..%s", start.Format(time.RFC3339), end.Format(time.RFC3339)),
+	}
+
+	var (
+		minTemp, maxTemp float64
+		hasTemp          bool
+		maxWind          float64
+		hasWind          bool
+		maxGust          float64
+		hasGust          bool
+		totalPrecip      float64
+		hasPrecip        bool
+	)
+
+	for _, pt := range res.Hourly {
+		if pt.TempC != nil {
+			if !hasTemp {
+				minTemp, maxTemp = *pt.TempC, *pt.TempC
+				hasTemp = true
+			} else {
+				if *pt.TempC < minTemp {
+					minTemp = *pt.TempC
+				}
+				if *pt.TempC > maxTemp {
+					maxTemp = *pt.TempC
+				}
+			}
+		}
+
+		if pt.WindMS != nil {
+			if !hasWind || *pt.WindMS > maxWind {
+				maxWind = *pt.WindMS
+				hasWind = true
+			}
+		}
+
+		if pt.WindGustMS != nil {
+			if !hasGust || *pt.WindGustMS > maxGust {
+				maxGust = *pt.WindGustMS
+				hasGust = true
+			}
+		}
+
+		if pt.PrecipMM != nil {
+			totalPrecip += *pt.PrecipMM
+			hasPrecip = true
+		}
+	}
+
+	if hasTemp {
+		parts = append(parts, fmt.Sprintf("temp_c(min=%.2f,max=%.2f)", minTemp, maxTemp))
+	}
+	if hasWind {
+		parts = append(parts, fmt.Sprintf("wind_ms(max=%.2f)", maxWind))
+	}
+	if hasGust {
+		parts = append(parts, fmt.Sprintf("gust_ms(max=%.2f)", maxGust))
+	}
+	if hasPrecip {
+		parts = append(parts, fmt.Sprintf("precip_mm(total=%.2f)", totalPrecip))
+	}
+
+	return strings.Join(parts, " ")
+}
+
+func logForecastDeviation(cache *ForecastCache, snap mqttingest.Snapshot) {
+	res := cache.Get()
+	if res == nil || len(res.Hourly) == 0 {
+		return
+	}
+
+	fc, diff := nearestForecastPoint(res.Hourly, snap.TS)
+	if fc == nil || diff > 2*time.Hour {
+		return
+	}
+
+	parts := []string{
+		fmt.Sprintf("model=%s", res.Model),
+		fmt.Sprintf("obs_ts=%s", snap.TS.Format(time.RFC3339)),
+		fmt.Sprintf("fc_ts=%s", fc.TS.Format(time.RFC3339)),
+		fmt.Sprintf("dt=%s", diff.Round(time.Minute)),
+	}
+
+	if fc.TempC != nil {
+		parts = append(parts, fmt.Sprintf(
+			"temp_c(obs=%.2f fc=%.2f d=%.2f)",
+			snap.P.TemperatureC, *fc.TempC, snap.P.TemperatureC-*fc.TempC,
+		))
+	}
+
+	if fc.WindMS != nil {
+		parts = append(parts, fmt.Sprintf(
+			"wind_ms(obs=%.2f fc=%.2f d=%.2f)",
+			snap.P.WindAvgMS, *fc.WindMS, snap.P.WindAvgMS-*fc.WindMS,
+		))
+	}
+
+	if fc.WindGustMS != nil {
+		parts = append(parts, fmt.Sprintf(
+			"gust_ms(obs=%.2f fc=%.2f d=%.2f)",
+			snap.P.WindMaxMS, *fc.WindGustMS, snap.P.WindMaxMS-*fc.WindGustMS,
+		))
+	}
+
+	if fc.WindDirDeg != nil {
+		dirDelta := angularDiffDeg(snap.P.WindDirDeg, *fc.WindDirDeg)
+		parts = append(parts, fmt.Sprintf(
+			"wind_dir_deg(obs=%.0f fc=%.0f d=%.0f)",
+			snap.P.WindDirDeg, *fc.WindDirDeg, dirDelta,
+		))
+	}
+
+	if fc.PrecipMM != nil {
+		parts = append(parts, fmt.Sprintf(
+			"rain_mm(obs=%.2f fc=%.2f d=%.2f)",
+			snap.RainLastHourMM, *fc.PrecipMM, snap.RainLastHourMM-*fc.PrecipMM,
+		))
+	}
+
+	if len(parts) <= 4 {
+		return
+	}
+
+	log.Printf("forecast deviation %s", strings.Join(parts, " "))
+}
+
+func nearestForecastPoint(hourly []providers.HourlyForecastPoint, ts time.Time) (*providers.HourlyForecastPoint, time.Duration) {
+	if len(hourly) == 0 {
+		return nil, 0
+	}
+
+	bestIdx := 0
+	bestDiff := absDuration(ts.Sub(hourly[0].TS))
+	for i := 1; i < len(hourly); i++ {
+		diff := absDuration(ts.Sub(hourly[i].TS))
+		if diff < bestDiff {
+			bestIdx = i
+			bestDiff = diff
+		}
+	}
+
+	return &hourly[bestIdx], bestDiff
+}
+
+func absDuration(d time.Duration) time.Duration {
+	if d < 0 {
+		return -d
+	}
+	return d
+}
+
+func angularDiffDeg(a, b float64) float64 {
+	diff := math.Mod(math.Abs(a-b), 360.0)
+	if diff > 180.0 {
+		diff = 360.0 - diff
+	}
+	return diff
+}