Exchange Rate Calculator (Unity)

ExchangeRate.cs

using UnityEngine;
using UniRx.Async;
using SimpleJSON;
using UnityEngine.Networking;

public enum Currency
{
    BGN, NZD, ILS, RUB, CAD, USD, PHP, CHF, AUD, JPY, TRY, HKD, MYR, HRK, CZK, IDR, DKK,
    NOK, HUF, GBP, MXN, THB, ISK, ZAR, BRL, SGD, PLN, INR, KRW, RON, CNY, SEK, EUR
}

public class ExchangeRateAPI
{

    static readonly string url = "https://api.exchangeratesapi.io/latest";

    Currency baseCurrency;

    public ExchangeRateAPI(Currency baseCurrency)
    {
        this.baseCurrency = baseCurrency;
    }

    public async UniTask<float> Exchange(float baseCurrencyValue, Currency targetCurrency)
    {
        return await Exchange(baseCurrencyValue, baseCurrency, targetCurrency);
    }

    public static async UniTask<float> Exchange(float baseCurrencyValue, Currency baseCurrency, Currency targetCurrency)
    {

        float rate = await GetRate(baseCurrency, targetCurrency);

        return baseCurrencyValue * rate;

    }

    public static async UniTask<float> GetRate(Currency baseCurrency, Currency targetCurrency)
    {

        var jsonStr = await GetExchangeRateJson(baseCurrency);

        var jsonNode = JSON.Parse(jsonStr);

        var rates = jsonNode["rates"];

        return rates[targetCurrency.ToString()].AsFloat;
    }


    static async UniTask<string> GetExchangeRateJson(Currency baseCurrency)
    {
        UnityWebRequest request = UnityWebRequest.Get($"{url}?base={baseCurrency.ToString()}");

        await request.SendWebRequest();

        if (request.isNetworkError)
        {
            Debug.LogError("Get: [Network Error]");
            return null;
        }
        else if (request.isHttpError)
        {
            Debug.LogError($"get: [Http Error] {request.downloadHandler.text}");
            return null;
        }
        else
        {
            return request.downloadHandler.text;
        }
    }

}

ExchangeTest.cs

using UnityEngine;

public class ExchangeTest : MonoBehaviour
{
    
    [Header("Base")]
    public Currency baseCurrency = Currency.JPY;
    public float value = 100;

    [Header("Target")]
    public Currency targetCurrency = Currency.USD;
    

    async void Start()
    {

        float result = await ExchangeRateAPI.Exchange(value, baseCurrency, targetCurrency);

        Debug.Log($"{result} [{targetCurrency.ToString()}]");
    }
    
    void Update()
    {
        
    }
}