Add Nordpool tariff (using elering.ee) (#7437)

tariff/elering.go

@@ -0,0 +1,119 @@
+package tariff
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/evcc-io/evcc/api"
+	"github.com/evcc-io/evcc/tariff/elering"
+	"github.com/evcc-io/evcc/util"
+	"github.com/evcc-io/evcc/util/request"
+	"golang.org/x/exp/slices"
+)
+
+type Elering struct {
+	mux     sync.Mutex
+	log     *util.Logger
+	unit    string
+	region  string
+	data    api.Rates
+	updated time.Time
+}
+
+var _ api.Tariff = (*Elering)(nil)
+
+func init() {
+	registry.Add("elering", NewEleringFromConfig)
+}
+
+func NewEleringFromConfig(other map[string]interface{}) (api.Tariff, error) {
+	cc := struct {
+		Currency string
+		Region   string
+	}{
+		Currency: "EUR",
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	if cc.Region == "" {
+		return nil, errors.New("missing region")
+	}
+
+	t := &Elering{
+		log:    util.NewLogger("Elering"),
+		unit:   cc.Currency,
+		region: strings.ToLower(cc.Region),
+	}
+
+	done := make(chan error)
+	go t.run(done)
+	err := <-done
+
+	return t, err
+}
+
+func (t *Elering) run(done chan error) {
+	var once sync.Once
+	client := request.NewHelper(t.log)
+
+	for ; true; <-time.Tick(time.Hour) {
+		var res elering.NpsPrice
+
+		ts := time.Now().Truncate(time.Hour)
+		uri := fmt.Sprintf("%s/nps/price?start=%s&end=%s", elering.URI,
+			url.QueryEscape(ts.Format(time.RFC3339)),
+			url.QueryEscape(ts.Add(48*time.Hour).Format(time.RFC3339)))
+
+		if err := client.GetJSON(uri, &res); err != nil {
+			once.Do(func() { done <- err })
+
+			t.log.ERROR.Println(err)
+			continue
+		}
+
+		once.Do(func() { close(done) })
+
+		t.mux.Lock()
+		t.updated = time.Now()
+
+		data := res.Data[t.region]
+
+		t.data = make(api.Rates, 0, len(data))
+		for _, r := range data {
+			ts := time.Unix(r.Timestamp, 0)
+
+			ar := api.Rate{
+				Start: ts.Local(),
+				End:   ts.Add(time.Hour).Local(),
+				Price: r.Price / 100,
+			}
+			t.data = append(t.data, ar)
+		}
+
+		t.mux.Unlock()
+	}
+}
+
+// Unit implements the api.Tariff interface
+func (t *Elering) Unit() string {
+	return t.unit
+}
+
+// Rates implements the api.Tariff interface
+func (t *Elering) Rates() (api.Rates, error) {
+	t.mux.Lock()
+	defer t.mux.Unlock()
+	return slices.Clone(t.data), outdatedError(t.updated, time.Hour)
+}
+
+// IsDynamic implements the api.Tariff interface
+func (t *Elering) IsDynamic() bool {
+	return true
+}

tariff/elering/types.go

@@ -0,0 +1,13 @@
+package elering
+
+const URI = "https://dashboard.elering.ee/api"
+
+type NpsPrice struct {
+	Success bool
+	Data    map[string][]Price
+}
+
+type Price struct {
+	Timestamp int64
+	Price     float64
+}