fix recorder npe, implement filters

pkg/weather/recorder/recorder_get.go

@@ -8,7 +8,6 @@ import (
 	"k8s.io/utils/ptr"
 
 	pb "gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/api/v1alpha1/weather"
-	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/util"
 	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
 )
 
@@ -27,10 +26,16 @@ func (w *WeatherRecorder) Get(ctx context.Context, req *pb.GetWeatherRequest) (
 		req.Limit = ptr.To(int32(1))
 	}
 
+	var filterSN, filterST string
+	if req.Opts != nil {
+		filterSN = req.Opts.GetStationName()
+		filterST = req.Opts.GetStationType()
+	}
+
 	ctx, span := w.tracer.Start(ctx, "getWeatherRecorder")
 	span.SetAttributes(
-		attribute.String("stationNameFilter", util.DerefStr(req.Opts.StationName)),
-		attribute.String("stationTypeFilter", util.DerefStr(req.Opts.StationType)),
+		attribute.String("stationNameFilter", filterSN),
+		attribute.String("stationTypeFilter", filterST),
 		attribute.Int("last", int(*req.Limit)),
 		attribute.Int("currentSize", w.Count(ctx)),
 	)

pkg/weather/recorder/recorders/memory/get.go

@@ -9,6 +9,7 @@ import (
 	"go.opentelemetry.io/otel/codes"
 
 	pb "gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/api/v1alpha1/weather"
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/util"
 	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
 )
 
@@ -23,8 +24,6 @@ func (r *MemoryRecorder) Get(ctx context.Context, req *pb.GetWeatherRequest) (
 
 	span.AddEvent("acquired lock on recorder cache")
 
-	updates := r.updates
-
 	if r.count() == 0 {
 		err := errors.New("no recorded updates to get")
 		span.RecordError(err)
@@ -33,24 +32,8 @@ func (r *MemoryRecorder) Get(ctx context.Context, req *pb.GetWeatherRequest) (
 		span.RecordError(errors.New("requested more updates than recorded"))
 	}
 
-	// Filter by Station Name if requested
-	if req.Opts.StationName != nil && *req.Opts.StationName != "" {
-		updates = slices.DeleteFunc(updates, func(u *weather.WeatherUpdate) bool {
-			return u.StationConfig == nil || u.StationConfig.Name != *req.Opts.StationName
-		})
-	}
-
-	// Filter by Station Type if requested
-	if req.Opts.StationType != nil && *req.Opts.StationType != "" {
-		updates = slices.DeleteFunc(updates, func(u *weather.WeatherUpdate) bool {
-			return u.StationType == nil || *u.StationType != *req.Opts.StationType
-		})
-	}
-
-	// Limit results
-	if len(updates) > int(*req.Limit) {
-		updates = updates[len(updates)-int(*req.Limit):]
-	}
+	updates := r.getUpdatesFromReq(req)
+	span.AddEvent("request limit/opts applied to updates")
 
 	span.SetAttributes(attribute.Int("retrieved", len(updates)))
 	span.SetStatus(codes.Ok, "")
@@ -58,6 +41,49 @@ func (r *MemoryRecorder) Get(ctx context.Context, req *pb.GetWeatherRequest) (
 	return updates, nil
 }
 
+func (r *MemoryRecorder) getUpdatesFromReq(req *pb.GetWeatherRequest) []*weather.WeatherUpdate {
+	if req.Opts == nil {
+		return limitUpdates(r.updates, int(req.GetLimit()))
+	}
+
+	return r.applyOptsToUpdates(r.updates, int(req.GetLimit()), req.Opts)
+}
+
+func (r *MemoryRecorder) applyOptsToUpdates(updates []*weather.WeatherUpdate, limit int, opts *pb.GetWeatherOpts) []*weather.WeatherUpdate {
+	if opts == nil {
+		return updates
+	} else if opts.StationName == nil && opts.StationType == nil {
+		return updates
+	}
+
+	filtered := make([]*weather.WeatherUpdate, 0, limit)
+
+	for i := len(updates) - 1; i >= 0; i-- {
+		update := updates[i]
+		match := true
+
+		if opts.GetStationName() != "" {
+			if update.GetStationName() != opts.GetStationName() {
+				match = false
+			}
+		}
+		if opts.GetStationType() != "" {
+			if util.DerefStr(update.StationType) != opts.GetStationType() {
+				match = false
+			}
+		}
+
+		if match {
+			filtered = append(filtered, update)
+			if len(filtered) >= limit {
+				return filtered
+			}
+		}
+	}
+
+	return slices.Clip(filtered)
+}
+
 func (r *MemoryRecorder) Count(ctx context.Context) int {
 	_, span := r.tracer.Start(ctx, "countWeatherRecorder")
 	defer span.End()
@@ -73,3 +99,10 @@ func (r *MemoryRecorder) Count(ctx context.Context) int {
 func (r *MemoryRecorder) count() int {
 	return len(r.updates)
 }
+
+func limitUpdates(updates []*weather.WeatherUpdate, limit int) []*weather.WeatherUpdate {
+	if len(updates) > limit {
+		return updates[len(updates)-limit:]
+	}
+	return updates
+}