Code cleanup and deduplication pass through weatherfeeder

internal/sources/nws/forecast_common.go

@@ -0,0 +1,114 @@
+package nws
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"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"
+)
+
+const nwsForecastAccept = "application/geo+json, application/json"
+
+type forecastSource struct {
+	http      *fksources.HTTPSource
+	rawSchema string
+}
+
+type forecastMeta struct {
+	Properties struct {
+		GeneratedAt string `json:"generatedAt"`
+		UpdateTime  string `json:"updateTime"`
+		Updated     string `json:"updated"`
+	} `json:"properties"`
+
+	ParsedGeneratedAt time.Time `json:"-"`
+	ParsedUpdateTime  time.Time `json:"-"`
+}
+
+func newForecastSource(cfg config.SourceConfig, driver, rawSchema string) (*forecastSource, error) {
+	hs, err := fksources.NewHTTPSource(driver, cfg, nwsForecastAccept)
+	if err != nil {
+		return nil, err
+	}
+
+	return &forecastSource{
+		http:      hs,
+		rawSchema: rawSchema,
+	}, nil
+}
+
+func (s *forecastSource) Name() string { return s.http.Name }
+
+func (s *forecastSource) Kind() event.Kind { return event.Kind("forecast") }
+
+func (s *forecastSource) Poll(ctx context.Context) ([]event.Event, error) {
+	raw, meta, changed, err := s.fetchRaw(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if !changed {
+		return nil, nil
+	}
+
+	var effectiveAt *time.Time
+	switch {
+	case !meta.ParsedGeneratedAt.IsZero():
+		t := meta.ParsedGeneratedAt.UTC()
+		effectiveAt = &t
+	case !meta.ParsedUpdateTime.IsZero():
+		t := meta.ParsedUpdateTime.UTC()
+		effectiveAt = &t
+	}
+
+	emittedAt := time.Now().UTC()
+	eventID := fksources.DefaultEventID("", s.http.Name, effectiveAt, emittedAt)
+
+	return fksources.SingleEvent(
+		s.Kind(),
+		s.http.Name,
+		s.rawSchema,
+		eventID,
+		emittedAt,
+		effectiveAt,
+		raw,
+	)
+}
+
+func (s *forecastSource) fetchRaw(ctx context.Context) (json.RawMessage, forecastMeta, bool, error) {
+	raw, changed, err := s.http.FetchJSONIfChanged(ctx)
+	if err != nil {
+		return nil, forecastMeta{}, false, err
+	}
+	if !changed {
+		return nil, forecastMeta{}, false, nil
+	}
+
+	var meta forecastMeta
+	if err := json.Unmarshal(raw, &meta); err != nil {
+		return raw, forecastMeta{}, true, nil
+	}
+
+	genStr := strings.TrimSpace(meta.Properties.GeneratedAt)
+	if genStr != "" {
+		if t, err := nwscommon.ParseTime(genStr); err == nil {
+			meta.ParsedGeneratedAt = t.UTC()
+		}
+	}
+
+	updStr := strings.TrimSpace(meta.Properties.UpdateTime)
+	if updStr == "" {
+		updStr = strings.TrimSpace(meta.Properties.Updated)
+	}
+	if updStr != "" {
+		if t, err := nwscommon.ParseTime(updStr); err == nil {
+			meta.ParsedUpdateTime = t.UTC()
+		}
+	}
+
+	return raw, meta, true, nil
+}