Sebastian Banzas exchange rates

.gitignore

@@ -21,3 +21,5 @@
 node_modules
 bower_components
 npm-debug.log
+*.vsidx
+*.v2

jobs/Backend/ExchangeRateUpdaterTest/ExchangeRateProviderTest.cs

@@ -0,0 +1,139 @@
+using ExchangeRateUpdater;
+using ExchangeRateUpdater.API.CNB;
+using ExchangeRateUpdater.API.CNB.Model.Responses;
+using Moq;
+
+namespace ExchangeRateUpdaterTest
+{
+    public class ExchangeRateProviderTest
+    {
+        private Mock<ICNBApiClient> _cnbApiClientMock;
+        private ExchangeRateProvider _exchangeRateProvider;
+
+        [SetUp]
+        public void Setup()
+        {
+            _cnbApiClientMock = new Mock<ICNBApiClient>();
+            _exchangeRateProvider = new ExchangeRateProvider(_cnbApiClientMock.Object);
+        }
+
+        [Test]
+        public async Task GetExchangeRates_ShouldReturnRatesForSpecifiedCurrencies()
+        {
+            // Arrange
+            var currencies = new List<Currency>
+            {
+                new Currency("USD"),
+                new Currency("EUR")
+            };
+
+            var apiResponse = new ExRateDailyResponse
+            {
+                Rates = new List<ExRateDailyRest>
+                {
+                    new ExRateDailyRest { CurrencyCode = "USD", Rate = 25.0m, Amount = 1,  },
+                    new ExRateDailyRest { CurrencyCode = "EUR", Rate = 27.0m, Amount = 1 },
+                    new ExRateDailyRest { CurrencyCode = "GBP", Rate = 30.0m, Amount = 1 }
+                }
+            };
+
+            _cnbApiClientMock.Setup(c => c.GetDailyRates(It.IsAny<string>(), It.IsAny<DateTime?>())).ReturnsAsync(apiResponse);
+
+            // Act
+            var result = await _exchangeRateProvider.GetExchangeRates(currencies);
+
+            // Assert
+            Assert.That(result.Count(), Is.EqualTo(2));
+            Assert.That(result.Any(r => r.SourceCurrency.Code == "USD"), Is.True);
+            Assert.That(result.Any(r => r.SourceCurrency.Code == "EUR"), Is.True);
+        }
+
+        [Test]
+        public async Task GetExchangeRates_ShouldIgnoreUndefinedCurrencies()
+        {
+            // Arrange
+            var currencies = new List<Currency>
+            {
+                new Currency("USD"),
+                new Currency("XYZ")
+            };
+
+            var apiResponse = new ExRateDailyResponse
+            {
+                Rates = new List<ExRateDailyRest>
+                {
+                    new ExRateDailyRest { CurrencyCode = "USD", Rate = 25.0m, Amount = 1 }
+                }
+            };
+
+            _cnbApiClientMock.Setup(c => c.GetDailyRates(It.IsAny<string>(), It.IsAny<DateTime?>())).ReturnsAsync(apiResponse);
+
+            // Act
+            var result = await _exchangeRateProvider.GetExchangeRates(currencies);
+
+            // Assert
+            Assert.That(result.Count(), Is.EqualTo(1));
+            Assert.That(result.Any(r => r.SourceCurrency.Code == "USD"), Is.True);
+            Assert.That(result.Any(r => r.SourceCurrency.Code == "XYZ"), Is.False);
+        }
+
+        [Test]
+        public async Task GetExchangeRates_ShouldReturnEmptyWhenNoRatesDefined()
+        {
+            // Arrange
+            var currencies = new List<Currency>
+            {
+                new Currency("USD"),
+                new Currency("EUR")
+            };
+
+            var apiResponse = new ExRateDailyResponse
+            {
+                Rates = new List<ExRateDailyRest>()
+            };
+
+            _cnbApiClientMock.Setup(c => c.GetDailyRates(It.IsAny<string>(), It.IsAny<DateTime?>())).ReturnsAsync(apiResponse);
+
+            // Act
+            var result = await _exchangeRateProvider.GetExchangeRates(currencies);
+
+            // Assert
+            Assert.That(result, Is.Empty);
+        }
+
+        [Test]
+        public async Task GetExchangeRates_ShouldHandleNullRatesFromApi()
+        {
+            // Arrange
+            var currencies = new List<Currency>
+            {
+                new Currency("USD"),
+                new Currency("EUR")
+            };
+
+            var apiResponse = new ExRateDailyResponse
+            {
+                Rates = null
+            };
+
+            _cnbApiClientMock.Setup(c => c.GetDailyRates(It.IsAny<string>(), It.IsAny<DateTime?>())).ReturnsAsync(apiResponse);
+
+            // Act
+            var result = await _exchangeRateProvider.GetExchangeRates(currencies);
+
+            // Assert
+            Assert.That(result, Is.Null);
+        }
+
+        [Test]
+        public void GetExchangeRates_ShouldThrowException_WhenApiClientFails()
+        {
+            // Arrange
+            var currencies = new List<Currency> { new Currency("USD") };
+            _cnbApiClientMock.Setup(c => c.GetDailyRates(It.IsAny<string>(), It.IsAny<DateTime?>())).ThrowsAsync(new Exception("API failure"));
+
+            // Act & Assert
+            Assert.ThrowsAsync<Exception>(() => _exchangeRateProvider.GetExchangeRates(currencies));
+        }
+    }
+}

jobs/Backend/ExchangeRateUpdaterTest/ExchangeRateUpdaterTest.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="Moq" Version="4.20.70" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
+    <PackageReference Include="NUnit.Analyzers" Version="3.3.0" />
+    <PackageReference Include="coverlet.collector" Version="3.1.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Task\ExchangeRateUpdater.csproj" />
+  </ItemGroup>
+
+</Project>

jobs/Backend/ExchangeRateUpdaterTest/Usings.cs

@@ -0,0 +1 @@
+global using NUnit.Framework;

jobs/Backend/Task/API/CNB/CNBApiClient.cs

@@ -0,0 +1,35 @@
+
+using ExchangeRateUpdater.API.CNB.Model.Responses;
+using System.Net.Http;
+using System.Threading.Tasks;
+using System.Net.Http.Json;
+using System;
+
+namespace ExchangeRateUpdater.API.CNB
+{
+    public interface ICNBApiClient
+    {
+        Task<ExRateDailyResponse> GetDailyRates(string lang = "EN", DateTime? date = null);
+    }
+
+    public class CNBApiClient : ICNBApiClient
+    {
+        private const string API_URL = "https://api.cnb.cz/cnbapi";
+        private const string EX_RATES = "exrates";
+        private const string DAILY_RATES = "daily";
+        public async Task<ExRateDailyResponse> GetDailyRates(string lang = "EN", DateTime? date = null)
+        {
+            using var hc = new HttpClient();
+            var query = DAILY_RATES + $"?lang={lang}";
+
+            if (date.HasValue)
+                query += $"date={date.Value:yyyy-MM-dd}";
+
+            var response = await hc.GetAsync(string.Join("/", API_URL, EX_RATES, query));
+
+            response.EnsureSuccessStatusCode();
+
+            return await response.Content.ReadFromJsonAsync<ExRateDailyResponse>();
+        }
+    }
+}

jobs/Backend/Task/API/CNB/Model/Responses/ExRateDailyResponse.cs

@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace ExchangeRateUpdater.API.CNB.Model.Responses
+{
+    public class ExRateDailyResponse
+    {
+        public IEnumerable<ExRateDailyRest> Rates { get; set; }
+    }
+}

jobs/Backend/Task/API/CNB/Model/Responses/ExRateDailyRest.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace ExchangeRateUpdater.API.CNB.Model.Responses
+{
+    public class ExRateDailyRest
+    {
+        public long Amount { get; set; }
+        public string Country { get; set; }
+        public string Currency { get; set; }
+        public string CurrencyCode { get; set; }
+        public int Order { get; set; }
+        public decimal Rate { get; set; }
+        public DateTime ValidFor { get; set; }
+    }
+}

jobs/Backend/Task/ExchangeRateProvider.cs

@@ -1,19 +1,33 @@
-using System.Collections.Generic;
+using ExchangeRateUpdater.API.CNB;
+using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 
 namespace ExchangeRateUpdater
 {
     public class ExchangeRateProvider
     {
+        private readonly ICNBApiClient _cnbApiClient;
+        public ExchangeRateProvider(ICNBApiClient cnbApiClient)
+        {
+            _cnbApiClient = cnbApiClient;
+        }
         /// <summary>
         /// Should return exchange rates among the specified currencies that are defined by the source. But only those defined
         /// by the source, do not return calculated exchange rates. E.g. if the source contains "CZK/USD" but not "USD/CZK",
         /// do not return exchange rate "USD/CZK" with value calculated as 1 / "CZK/USD". If the source does not provide
         /// some of the currencies, ignore them.
         /// </summary>
-        public IEnumerable<ExchangeRate> GetExchangeRates(IEnumerable<Currency> currencies)
+        /// 
+
+        public async Task<IEnumerable<ExchangeRate>> GetExchangeRates(IEnumerable<Currency> currencies)
         {
-            return Enumerable.Empty<ExchangeRate>();
+            var currencyCodes = currencies.Select(c => c.Code).ToList();
+
+            var result = await _cnbApiClient.GetDailyRates();
+
+            return result.Rates?.Where(r => currencyCodes.Contains(r.CurrencyCode))
+                .Select(r => new ExchangeRate(new Currency(r.CurrencyCode), new Currency("CZK"), r.Rate / r.Amount));
         }
     }
 }

jobs/Backend/Task/ExchangeRateUpdater.sln

@@ -1,9 +1,11 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.25123.0
+# Visual Studio Version 17
+VisualStudioVersion = 17.10.35004.147
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExchangeRateUpdater", "ExchangeRateUpdater.csproj", "{7B2695D6-D24C-4460-A58E-A10F08550CE0}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ExchangeRateUpdater", "ExchangeRateUpdater.csproj", "{7B2695D6-D24C-4460-A58E-A10F08550CE0}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExchangeRateUpdaterTest", "..\ExchangeRateUpdaterTest\ExchangeRateUpdaterTest.csproj", "{F481C6F8-6A36-4803-AF21-C0A6CD26C488}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -15,8 +17,15 @@ Global
 		{7B2695D6-D24C-4460-A58E-A10F08550CE0}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7B2695D6-D24C-4460-A58E-A10F08550CE0}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7B2695D6-D24C-4460-A58E-A10F08550CE0}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F481C6F8-6A36-4803-AF21-C0A6CD26C488}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F481C6F8-6A36-4803-AF21-C0A6CD26C488}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F481C6F8-6A36-4803-AF21-C0A6CD26C488}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F481C6F8-6A36-4803-AF21-C0A6CD26C488}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {51DB8E9B-E93F-4E6C-8A82-82669B4DCAE2}
+	EndGlobalSection
 EndGlobal

jobs/Backend/Task/Program.cs

@@ -1,6 +1,8 @@
-using System;
+using ExchangeRateUpdater.API.CNB;
+using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading.Tasks;
 
 namespace ExchangeRateUpdater
 {
@@ -19,12 +21,13 @@ public static class Program
             new Currency("XYZ")
         };
 
-        public static void Main(string[] args)
+        public static async Task Main(string[] args)
         {
             try
             {
-                var provider = new ExchangeRateProvider();
-                var rates = provider.GetExchangeRates(currencies);
+                var cnbApiClient = new CNBApiClient();
+                var provider = new ExchangeRateProvider(cnbApiClient);
+                var rates = await provider.GetExchangeRates(currencies);
 
                 Console.WriteLine($"Successfully retrieved {rates.Count()} exchange rates:");
                 foreach (var rate in rates)