Add circulating endpoint

dash-backend.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"github.com/spacemeshos/dash-backend/utils"
 	"io"
 	"math/rand"
 	"net/http"
@@ -105,6 +106,18 @@ func main() {
 			}
 		})
 
+		http.HandleFunc("/circulating", func(w http.ResponseWriter, r *http.Request) {
+			stats := history.GetStats()
+			var circulation int64 = 0
+			for _, val := range stats.Circulation {
+				circulation += val.Amt
+			}
+			c := utils.ParseSmidge(float64(circulation))
+
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(c.Value))
+		})
+
 		err = http.ListenAndServe(listenStringFlag, nil)
 		if err != nil {
 			log.Err(fmt.Errorf("Create HTTP ssrver error: %v", err))

history/history.go

@@ -91,6 +91,15 @@ func getObject(d *bson.D, name string) *bson.E {
 }
 
 func (h *History) pushStatistics() {
+	message := h.GetStats()
+	h.bus.Notify <- message.ToJson()
+}
+
+func (h *History) push(m *api.Message) {
+	h.bus.Notify <- m.ToJson()
+}
+
+func (h *History) GetStats() *api.Message {
 	var i int
 
 	now := uint32(time.Now().Unix())
@@ -166,9 +175,5 @@ func (h *History) pushStatistics() {
 		}
 	}
 
-	h.bus.Notify <- message.ToJson()
-}
-
-func (h *History) push(m *api.Message) {
-	h.bus.Notify <- m.ToJson()
+	return message
 }

utils/converter.go

@@ -0,0 +1,42 @@
+package utils
+
+import (
+	"math"
+	"strconv"
+)
+
+type CoinUnits struct {
+	SMH    string
+	Smidge string
+}
+
+var coinUnits = CoinUnits{
+	SMH:    "SMH",
+	Smidge: "Smidge",
+}
+
+type Coin struct {
+	Value string
+	Unit  string
+}
+
+func packValueAndUnit(value float64, unit string) Coin {
+	return Coin{
+		Value: strconv.FormatFloat(value, 'f', 3, 64),
+		Unit:  unit,
+	}
+}
+
+func ParseSmidge(amount float64) Coin {
+	if amount <= 0 || math.IsNaN(amount) {
+		return packValueAndUnit(0, coinUnits.SMH)
+	}
+	if amount >= math.Pow10(6) {
+		return packValueAndUnit(toSMH(amount), coinUnits.SMH)
+	}
+	return packValueAndUnit(amount, coinUnits.Smidge)
+}
+
+func toSMH(smidge float64) float64 {
+	return smidge / math.Pow10(9)
+}