Plugins: add timeseries (#18049)

provider/timeseries.go

@@ -0,0 +1,40 @@
+package provider
+
+import (
+	"context"
+	"encoding/json"
+	"time"
+
+	"github.com/evcc-io/evcc/api"
+	"github.com/jinzhu/now"
+)
+
+type timeseriesProvider struct{}
+
+func init() {
+	registry.AddCtx("timeseries", TimeSeriesFromConfig)
+}
+
+// TimeSeriesFromConfig creates timeseries provider
+func TimeSeriesFromConfig(_ context.Context, _ map[string]interface{}) (Provider, error) {
+	return new(timeseriesProvider), nil
+}
+
+var _ StringProvider = (*timeseriesProvider)(nil)
+
+func (p *timeseriesProvider) StringGetter() (func() (string, error), error) {
+	return func() (string, error) {
+		res := make(api.Rates, 48)
+		ts := now.BeginningOfHour()
+		for i := 0; i < 48; i++ {
+			res[i] = api.Rate{
+				Start: ts,
+				End:   ts.Add(time.Hour),
+			}
+			ts = ts.Add(time.Hour)
+		}
+
+		b, err := json.Marshal(res)
+		return string(b), err
+	}, nil
+}