add new bitcoin electrum SPV provider

providers/bitcoinElectrum/fiat.go

@@ -0,0 +1,63 @@
+package bitcoinElectrum
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+const fiatConvertURL = "https://api.coingecko.com/api/v3/coins/bitcoin?localization=false&tickers=false&market_data=true&community_data=false&developer_data=false&sparkline=false"
+
+type coinGeckoResponse struct {
+	MarketData struct {
+		CurrentPrice struct {
+			CAD int `json:"cad"`
+		} `json:"current_price"`
+	} `json:"market_data"`
+}
+
+func convertBTCToCAD(amount int, coinGeckoApiKey string) (int, error) {
+	coinGeckoData := &coinGeckoResponse{}
+
+	req, err := http.NewRequest("GET", fmt.Sprintf("%s&x-cg-demo-api-key=%s", fiatConvertURL, coinGeckoApiKey), nil)
+	if err != nil {
+		return 0, fmt.Errorf("failed to create new GET request: %v", err)
+	}
+
+	client := http.Client{Transport: &http.Transport{ResponseHeaderTimeout: 15 * time.Second}}
+	res, err := client.Do(req)
+	if err != nil {
+		return 0, fmt.Errorf("http GET request failed: %v", err)
+	}
+
+	err = processResponse(res, coinGeckoData)
+	if err != nil {
+		return 0, fmt.Errorf("failed to process response: %v", err)
+	}
+
+	return (amount * int(coinGeckoData.MarketData.CurrentPrice.CAD*1000)) / 100000000, nil // one BTC = one hundred million satoshi's
+}
+
+// processResponse takes the body of an HTTP response, and either returns
+// the error code, or unmarshalls the JSON response, extracts
+// rate limit info, and places it into the object
+// output parameter. This function closes the response body after reading it.
+func processResponse(res *http.Response, out interface{}) error {
+	body, err := io.ReadAll(res.Body)
+	res.Body.Close()
+	if err != nil {
+		return fmt.Errorf("failed to read response body: %v", err)
+	}
+
+	if res.StatusCode != 200 && res.StatusCode != 201 {
+		return fmt.Errorf("unexpected http status code '%d': %v", res.StatusCode, err)
+	}
+
+	err = json.Unmarshal(body, out)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal response body: %v", err)
+	}
+	return nil
+}