Moved HTTP polling helpers upstream into feedkit, and updated to feedkit v0.8.0

internal/sources/nws/forecast_narrative.go

@@ -9,6 +9,7 @@ import (
 
 	"gitea.maximumdirect.net/ejr/feedkit/config"
 	"gitea.maximumdirect.net/ejr/feedkit/event"
+	fksources "gitea.maximumdirect.net/ejr/feedkit/sources"
 	nwscommon "gitea.maximumdirect.net/ejr/weatherfeeder/internal/providers/nws"
 	"gitea.maximumdirect.net/ejr/weatherfeeder/internal/sources/common"
 	"gitea.maximumdirect.net/ejr/weatherfeeder/standards"
@@ -22,14 +23,14 @@ import (
 // Output schema:
 //   - standards.SchemaRawNWSNarrativeForecastV1
 type NarrativeForecastSource struct {
-	http *common.HTTPSource
+	http *fksources.HTTPSource
 }
 
 func NewNarrativeForecastSource(cfg config.SourceConfig) (*NarrativeForecastSource, error) {
 	const driver = "nws_forecast_narrative"
 
 	// NWS forecast endpoints are GeoJSON (and sometimes also advertise json-ld/json).
-	hs, err := common.NewHTTPSource(driver, cfg, "application/geo+json, application/json")
+	hs, err := fksources.NewHTTPSource(driver, cfg, "application/geo+json, application/json")
 	if err != nil {
 		return nil, err
 	}
@@ -43,10 +44,13 @@ func (s *NarrativeForecastSource) Name() string { return s.http.Name }
 func (s *NarrativeForecastSource) Kind() event.Kind { return event.Kind("forecast") }
 
 func (s *NarrativeForecastSource) Poll(ctx context.Context) ([]event.Event, error) {
-	raw, meta, err := s.fetchRaw(ctx)
+	raw, meta, changed, err := s.fetchRaw(ctx)
 	if err != nil {
 		return nil, err
 	}
+	if !changed {
+		return nil, nil
+	}
 
 	// EffectiveAt is optional; for forecasts it’s most naturally the run “issued” time.
 	// NWS gridpoint forecasts expose generatedAt (preferred) and updateTime/updated.
@@ -94,16 +98,19 @@ type narrativeForecastMeta struct {
 	ParsedUpdateTime  time.Time `json:"-"`
 }
 
-func (s *NarrativeForecastSource) fetchRaw(ctx context.Context) (json.RawMessage, narrativeForecastMeta, error) {
-	raw, err := s.http.FetchJSON(ctx)
+func (s *NarrativeForecastSource) fetchRaw(ctx context.Context) (json.RawMessage, narrativeForecastMeta, bool, error) {
+	raw, changed, err := s.http.FetchJSONIfChanged(ctx)
 	if err != nil {
-		return nil, narrativeForecastMeta{}, err
+		return nil, narrativeForecastMeta{}, false, err
+	}
+	if !changed {
+		return nil, narrativeForecastMeta{}, false, nil
 	}
 
 	var meta narrativeForecastMeta
 	if err := json.Unmarshal(raw, &meta); err != nil {
 		// If metadata decode fails, still return raw; Poll will fall back to Source:EmittedAt.
-		return raw, narrativeForecastMeta{}, nil
+		return raw, narrativeForecastMeta{}, true, nil
 	}
 
 	// generatedAt (preferred)
@@ -125,5 +132,5 @@ func (s *NarrativeForecastSource) fetchRaw(ctx context.Context) (json.RawMessage
 		}
 	}
 
-	return raw, meta, nil
+	return raw, meta, true, nil
 }