Add special rate provider for qudrigacx

BTCPayServer.Tests/UnitTest1.cs

@@ -633,7 +633,7 @@ namespace BTCPayServer.Tests
                 Assert.Equal(bitflyer, bitflyer2); // Should be equal because cache
                 rates.Add(bitflyer);
 
-                foreach(var rate in rates)
+                foreach (var rate in rates)
                 {
                     Assert.Single(rates.Where(r => r == rate));
                 }
@@ -1185,6 +1185,26 @@ namespace BTCPayServer.Tests
             }
         }
 
+        [Fact]
+        public void CheckQuadrigacxRateProvider()
+        {
+            var quadri = new QuadrigacxRateProvider("BTC");
+            var rates = quadri.GetRatesAsync().GetAwaiter().GetResult();
+            Assert.NotEmpty(rates);
+            Assert.NotEqual(0.0m, rates.First().Value);
+            Assert.NotEqual(0.0m, quadri.GetRateAsync("CAD").GetAwaiter().GetResult());
+            Assert.NotEqual(0.0m, quadri.GetRateAsync("USD").GetAwaiter().GetResult());
+            Assert.Throws<RateUnavailableException>(() => quadri.GetRateAsync("IOEW").GetAwaiter().GetResult());
+
+            quadri = new QuadrigacxRateProvider("LTC");
+            rates = quadri.GetRatesAsync().GetAwaiter().GetResult();
+            Assert.NotEmpty(rates);
+            Assert.NotEqual(0.0m, rates.First().Value);
+            Assert.NotEqual(0.0m, quadri.GetRateAsync("CAD").GetAwaiter().GetResult());
+            Assert.Throws<RateUnavailableException>(() => quadri.GetRateAsync("IOEW").GetAwaiter().GetResult());
+            Assert.Throws<RateUnavailableException>(() => quadri.GetRateAsync("USD").GetAwaiter().GetResult());
+        }
+
         [Fact]
         public void CheckRatesProvider()
         {

BTCPayServer/Services/Rates/BTCPayRateProviderFactory.cs

@@ -65,9 +65,17 @@ namespace BTCPayServer.Services.Rates
 
         private IRateProvider CreateExchangeRateProvider(BTCPayNetwork network, string exchange)
         {
+            List<IRateProvider> providers = new List<IRateProvider>();
+
+            if(exchange == "quadrigacx")
+            {
+                providers.Add(new QuadrigacxRateProvider(network.CryptoCode));
+            }
+
             var coinAverage = new CoinAverageRateProviderDescription(network.CryptoCode).CreateRateProvider(serviceProvider);
             coinAverage.Exchange = exchange;
-            return coinAverage;
+            providers.Add(coinAverage);
+            return new FallbackRateProvider(providers.ToArray());
         }
 
         private CachedRateProvider CreateCachedRateProvider(BTCPayNetwork network, IRateProvider rateProvider, string additionalScope)

BTCPayServer/Services/Rates/QuadrigacxRateProvider.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Services.Rates
+{
+    public class QuadrigacxRateProvider : IRateProvider
+    {
+        public QuadrigacxRateProvider(string crypto)
+        {
+            CryptoCode = crypto;
+        }
+        public string CryptoCode { get; set; }
+        static HttpClient _Client = new HttpClient();
+        public async Task<decimal> GetRateAsync(string currency)
+        {
+            return await GetRatesAsyncCore(CryptoCode, currency);
+        }
+
+        private async Task<decimal> GetRatesAsyncCore(string cryptoCode, string currency)
+        {
+            var response = await _Client.GetAsync($"https://api.quadrigacx.com/v2/ticker?book={cryptoCode.ToLowerInvariant()}_{currency.ToLowerInvariant()}");
+            response.EnsureSuccessStatusCode();
+            var rates = JObject.Parse(await response.Content.ReadAsStringAsync());
+            if (!TryToDecimal(rates, out var result))
+                throw new RateUnavailableException(currency);
+            return result;
+        }
+
+        private bool TryToDecimal(JObject p, out decimal v)
+        {
+            v = 0.0m;
+            JToken token = p.Property("bid")?.Value;
+            if (token == null)
+                return false;
+            return decimal.TryParse(token.Value<string>(), System.Globalization.NumberStyles.AllowExponent | System.Globalization.NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out v);
+        }
+
+        public async Task<ICollection<Rate>> GetRatesAsync()
+        {
+            List<Rate> result = new List<Rate>();
+            // https://www.quadrigacx.com/api_info
+            foreach(var q in new[] { (Crypto: "BTC", Currency:"CAD" ),
+                (Crypto: "BTC", Currency:"USD" ),
+                (Crypto: "ETH", Currency:"CAD" ),
+                (Crypto: "LTC", Currency:"CAD" ),
+                (Crypto: "BCH", Currency:"CAD" ),
+                (Crypto: "BTG", Currency:"CAD" ) }
+            .Where(c => CryptoCode == c.Crypto)
+            .Select(c => (Crypto: c.Crypto, Currency: c.Currency, Rate: GetRatesAsyncCore(c.Crypto, c.Currency))))
+            {
+                try
+                {
+                    result.Add(new Rate() { Currency = q.Currency, Value = await q.Rate });
+                }
+                catch(RateUnavailableException) { }
+            }
+            return result;
+        }
+    }
+}