Gerard Backend Task

.gitignore

@@ -21,3 +21,5 @@
 node_modules
 bower_components
 npm-debug.log
+*.vsidx
+/jobs/Backend/Task/.vs/ExchangeRates/v17/TestStore/0

jobs/Backend/Task/ExchangeRates.sln

@@ -0,0 +1,28 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExchangesRatesApp", "src\ExchangesRatesApp.csproj", "{0C2EC045-59FC-4AE7-B39E-C3FD037096A6}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExchangeRatesTests", "test\ExchangeRatesTests.csproj", "{CE380A25-4484-41B4-BEC0-FC3292A46DF7}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{0C2EC045-59FC-4AE7-B39E-C3FD037096A6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0C2EC045-59FC-4AE7-B39E-C3FD037096A6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0C2EC045-59FC-4AE7-B39E-C3FD037096A6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0C2EC045-59FC-4AE7-B39E-C3FD037096A6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CE380A25-4484-41B4-BEC0-FC3292A46DF7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CE380A25-4484-41B4-BEC0-FC3292A46DF7}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CE380A25-4484-41B4-BEC0-FC3292A46DF7}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CE380A25-4484-41B4-BEC0-FC3292A46DF7}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal

jobs/Backend/Task/src/ExchangesRatesApp.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration" Version="6.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Http" Version="6.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="6.0.0" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="local.settings.json">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+</Project>

jobs/Backend/Task/src/Models/CnbRateDailyResponse.cs

@@ -0,0 +1,18 @@
+namespace ExchangeRateUpdater.Models
+{
+    public class CnbRateDailyResponse
+    {
+        public IEnumerable<CnbRate> Rates { get; set; }
+    }
+
+    public class CnbRate
+    {
+        public string ValidFor { get; set; }
+        public int Order { get; set; }
+        public string Country { get; set; }
+        public string Currency { get; set; }
+        public int Amount { get; set; }
+        public string CurrencyCode { get; set; }
+        public decimal Rate { get; set; }
+    }
+}

jobs/Backend/Task/Currency.cs → jobs/Backend/Task/src/Models/Currency.cs

@@ -1,4 +1,4 @@
-namespace ExchangeRateUpdater
+namespace ExchangeRateUpdater.Models
 {
     public class Currency
     {

jobs/Backend/Task/ExchangeRate.cs → jobs/Backend/Task/src/Models/ExchangeRate.cs

@@ -1,4 +1,4 @@
-namespace ExchangeRateUpdater
+namespace ExchangeRateUpdater.Models
 {
     public class ExchangeRate
     {

jobs/Backend/Task/src/Options/CnbApiOptions.cs

@@ -0,0 +1,10 @@
+namespace ExchangeRateUpdater.Options
+{
+    public class CnbApiOptions
+    {
+        public const string OptionsName = "CnbApi";
+        public const string ClientName = "CnbClient";
+
+        public string BaseAddress { get; set; }
+    }
+}

jobs/Backend/Task/src/Options/CurrenciesOptions.cs

@@ -0,0 +1,9 @@
+namespace ExchangeRateUpdater.Options
+{
+    public class CurrenciesOptions
+    {
+        public const string OptionsName = "CurrenciesOptions";
+
+        public IEnumerable<string> Currencies { get; set; }
+    }
+}

jobs/Backend/Task/src/Program.cs

@@ -0,0 +1,64 @@
+using ExchangeRateUpdater.Models;
+using ExchangeRateUpdater.Options;
+using ExchangeRateUpdater.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Http;
+
+namespace ExchangeRateUpdater
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            var host = CreateHostBuilder(args).Build();
+
+            var rates = host.Services.GetService<IExchangeRateProvider>().GetExchangeRates(System.Threading.CancellationToken.None).GetAwaiter().GetResult();
+
+            foreach (var rate in rates)
+            {
+                Console.WriteLine(rate.ToString());
+            }
+        }
+
+        private static IHostBuilder CreateHostBuilder(string[] args)
+        {
+            var _configuration = new ConfigurationBuilder()
+                .AddJsonFile("local.settings.json",
+                    optional: true,
+                    reloadOnChange: true)
+                .Build();
+
+            var hostBuilder = Host.CreateDefaultBuilder(args)
+                .ConfigureAppConfiguration((context, builder) =>
+                {
+                    builder.SetBasePath(Directory.GetCurrentDirectory());
+                })
+                .ConfigureServices((context, services) =>
+                {
+                    // Remove httpClient default Console.WriteLine behaviour
+                    services.RemoveAll<IHttpMessageHandlerBuilderFilter>();
+
+                    // Options
+                    services.Configure<CurrenciesOptions>(_configuration.GetSection(CurrenciesOptions.OptionsName));
+
+                    var cnbApiOptions = new CnbApiOptions();
+                    _configuration.GetSection(CnbApiOptions.OptionsName).Bind(cnbApiOptions);
+
+                    // Services
+                    services.AddSingleton<IExchangeRateProvider, ExchangeRateProvider>();
+                    services.AddSingleton<ICnbApiService, CnbApiService>();
+
+                    // CnbHttpClient
+                    services.AddHttpClient(CnbApiOptions.ClientName, x =>
+                    {
+                        x.BaseAddress = new Uri(cnbApiOptions.BaseAddress);
+                    });
+                });
+
+            return hostBuilder;
+        }
+    }
+}

jobs/Backend/Task/src/Services/CnbApiService.cs

@@ -0,0 +1,46 @@
+using ExchangeRateUpdater.Models;
+using ExchangeRateUpdater.Options;
+using Newtonsoft.Json;
+using Microsoft.Extensions.Options;
+
+namespace ExchangeRateUpdater.Services
+{
+    public class CnbApiService : ICnbApiService
+    {
+        private readonly string GET_RATES_ENDPOINT = "/cnbapi/exrates/daily";
+
+        private readonly HttpClient _client;
+
+        public CnbApiService(IHttpClientFactory clientFactory)
+        {
+            _client = clientFactory.CreateClient(CnbApiOptions.ClientName);
+        }
+
+        public async Task<CnbRateDailyResponse> GetExchangeRate(CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            var httpRequest = new HttpRequestMessage
+            {
+                Method = HttpMethod.Get,
+                RequestUri = new Uri(GET_RATES_ENDPOINT, UriKind.Relative)
+            };
+
+            var httpResponse = await _client.SendAsync(httpRequest, cancellationToken);
+
+            if (!httpResponse.IsSuccessStatusCode)
+            {
+                return new CnbRateDailyResponse
+                {
+                    Rates = new List<CnbRate>()
+                };
+            }
+
+            var response = await httpResponse.Content.ReadAsStringAsync(cancellationToken);
+
+            var cnbRates = JsonConvert.DeserializeObject<CnbRateDailyResponse>(response);
+
+            return cnbRates;
+        }
+    }
+}

jobs/Backend/Task/src/Services/ExchangeRateProvider.cs

@@ -0,0 +1,58 @@
+using ExchangeRateUpdater.Models;
+using ExchangeRateUpdater.Options;
+using Microsoft.Extensions.Options;
+
+namespace ExchangeRateUpdater.Services
+{
+    public class ExchangeRateProvider : IExchangeRateProvider
+    {
+        /// <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>
+
+        private readonly ICnbApiService _cnbApiService;
+        private readonly CurrenciesOptions _currenciesOptions;
+
+        public ExchangeRateProvider(
+            ICnbApiService cnbApiService,
+            IOptionsMonitor<CurrenciesOptions> currenciesOptions
+        )
+        {
+            _cnbApiService = cnbApiService;
+            _currenciesOptions = currenciesOptions.CurrentValue;
+        }
+
+        public async Task<IEnumerable<ExchangeRate>> GetExchangeRates(CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            // GET CNB RATES
+            var cnbRates = await _cnbApiService.GetExchangeRate(cancellationToken);
+
+            var result = new List<ExchangeRate>();
+
+            foreach (var currencyCode in _currenciesOptions.Currencies)
+            {
+                var currencyTarget = new Currency(currencyCode);
+
+                var rate = cnbRates.Rates.FirstOrDefault(x => x.CurrencyCode.Equals(currencyTarget.Code));
+
+                if (rate == null)
+                {
+                    continue;
+                }
+
+                var value = rate.Rate / rate.Amount;
+
+                var exchangeRate = new ExchangeRate(new Currency("CZK"), currencyTarget, value);
+
+                result.Add(exchangeRate);
+            }
+
+            return result;
+        }
+    }
+}

jobs/Backend/Task/src/Services/ICnbApiService.cs

@@ -0,0 +1,9 @@
+using ExchangeRateUpdater.Models;
+
+namespace ExchangeRateUpdater.Services
+{
+    public interface ICnbApiService
+    {
+        Task<CnbRateDailyResponse> GetExchangeRate(CancellationToken cancellationToken);
+    }
+}