goCake/coinGeckoAPI.go

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
)

// CheckStatusCoinGecko needs a comment
func CheckStatusCoinGecko() bool {
	// needed answer for Coingecko API
	type statusResponse struct {
		GeckoSays string `json:"gecko_says"`
	}

	// see if API is available
	url := "https://api.coingecko.com/api/v3/ping"
	response, err := http.Get(url)
	if err == nil {
		var status statusResponse
		readBody(response, &status)
		if status.GeckoSays == "(V3) To the Moon!" {
			// API is working as expected
			return true
		}
	}
	return false
}

// GetCoinValue needs a comment
func GetCoinValue(coinID string, fiat string) (float64, error) {
	// check if API is up
	if CheckStatusCoinGecko() == true {
		// https://api.coingecko.com/api/v3/simple/price?ids=defichain&vs_currencies=eur
		url := "https://api.coingecko.com/api/v3/simple/price?ids=" + coinID + "&vs_currencies=" + fiat
		response, err := http.Get(url)
		if err == nil {
			// there's no error, we got a response
			var r map[string]interface{}
			readBody(response, &r)
			// as the response will vary on coin and fiat we need to use interface{} here
			value := r[coinID].(map[string]interface{})
			return value[fiat].(float64), nil
		}
		return 0, fmt.Errorf("There was a problem with the response from Coingecko, Error is: %s", err.Error())
	}
	return 0, fmt.Errorf("The API of Coingecko seems to be down")
}

func readBody(h *http.Response, i interface{}) {
	// API is available, let's read the response
	data, _ := ioutil.ReadAll(h.Body)
	json.Unmarshal(data, i)
}