fix forecast data

cmd/ingestd/web.go

@@ -147,7 +147,7 @@ func (s *webServer) handleDashboard(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	forecast, err := s.db.ForecastSeriesLatest(r.Context(), s.site.Name, s.model)
+	forecast, err := s.db.ForecastSeriesRange(r.Context(), s.site.Name, s.model, start, end)
 	if err != nil {
 		http.Error(w, "failed to query forecast", http.StatusInternalServerError)
 		log.Printf("web dashboard forecast error: %v", err)

internal/db/series.go

@@ -223,6 +223,65 @@ func (d *DB) ForecastSeriesLatest(ctx context.Context, site, model string) (Fore
 	}, nil
 }
 
+func (d *DB) ForecastSeriesRange(ctx context.Context, site, model string, start, end time.Time) (ForecastSeries, error) {
+	rows, err := d.Pool.Query(ctx, `
+		SELECT DISTINCT ON (ts)
+			ts,
+			retrieved_at,
+			temp_c,
+			rh,
+			pressure_msl_hpa,
+			wind_m_s,
+			wind_gust_m_s,
+			wind_dir_deg,
+			precip_mm,
+			cloud_cover
+		FROM forecast_openmeteo_hourly
+		WHERE site = $1 AND model = $2 AND ts >= $3 AND ts <= $4
+		ORDER BY ts ASC, retrieved_at DESC
+	`, site, model, start, end)
+	if err != nil {
+		return ForecastSeries{}, err
+	}
+	defer rows.Close()
+
+	points := make([]ForecastPoint, 0, 256)
+	var maxRetrieved time.Time
+	for rows.Next() {
+		var (
+			ts                        time.Time
+			retrieved                 time.Time
+			temp, rh, msl, wind, gust sql.NullFloat64
+			dir, precip, cloud        sql.NullFloat64
+		)
+		if err := rows.Scan(&ts, &retrieved, &temp, &rh, &msl, &wind, &gust, &dir, &precip, &cloud); err != nil {
+			return ForecastSeries{}, err
+		}
+		if retrieved.After(maxRetrieved) {
+			maxRetrieved = retrieved
+		}
+		points = append(points, ForecastPoint{
+			TS:           ts,
+			TempC:        nullFloatPtr(temp),
+			RH:           nullFloatPtr(rh),
+			PressureMSLH: nullFloatPtr(msl),
+			WindMS:       nullFloatPtr(wind),
+			WindGustMS:   nullFloatPtr(gust),
+			WindDirDeg:   nullFloatPtr(dir),
+			PrecipMM:     nullFloatPtr(precip),
+			CloudCover:   nullFloatPtr(cloud),
+		})
+	}
+	if rows.Err() != nil {
+		return ForecastSeries{}, rows.Err()
+	}
+
+	return ForecastSeries{
+		RetrievedAt: maxRetrieved,
+		Points:      points,
+	}, nil
+}
+
 func nullFloatPtr(v sql.NullFloat64) *float64 {
 	if !v.Valid {
 		return nil