Added support for Area Forecast Discussions issued by the NWS

internal/sources/nws/forecast_discussion.go

@@ -0,0 +1,68 @@
+package nws
+
+import (
+	"context"
+	"time"
+
+	"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/standards"
+)
+
+// ForecastDiscussionSource polls an NWS forecast discussion HTML page and emits a RAW discussion Event.
+//
+// Output schema:
+//   - standards.SchemaRawNWSForecastDiscussionV1
+type ForecastDiscussionSource struct {
+	http *fksources.HTTPSource
+}
+
+func NewForecastDiscussionSource(cfg config.SourceConfig) (*ForecastDiscussionSource, error) {
+	const driver = "nws_forecast_discussion"
+
+	hs, err := fksources.NewHTTPSource(driver, cfg, "text/html, application/xhtml+xml")
+	if err != nil {
+		return nil, err
+	}
+
+	return &ForecastDiscussionSource{http: hs}, nil
+}
+
+func (s *ForecastDiscussionSource) Name() string { return s.http.Name }
+
+func (s *ForecastDiscussionSource) Kinds() []event.Kind {
+	return []event.Kind{event.Kind("forecast_discussion")}
+}
+
+func (s *ForecastDiscussionSource) Poll(ctx context.Context) ([]event.Event, error) {
+	body, changed, err := s.http.FetchBytesIfChanged(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if !changed {
+		return nil, nil
+	}
+
+	rawHTML := string(body)
+	parsed, err := nwscommon.ParseForecastDiscussionHTML(rawHTML)
+	if err != nil {
+		return nil, err
+	}
+
+	issuedAt := parsed.IssuedAt.UTC()
+	effectiveAt := &issuedAt
+	emittedAt := time.Now().UTC()
+	eventID := fksources.DefaultEventID("", s.http.Name, effectiveAt, emittedAt)
+
+	return fksources.SingleEvent(
+		event.Kind("forecast_discussion"),
+		s.http.Name,
+		standards.SchemaRawNWSForecastDiscussionV1,
+		eventID,
+		emittedAt,
+		effectiveAt,
+		rawHTML,
+	)
+}