Isaac Rossell I Ripoll Take home

.gitignore

@@ -21,3 +21,5 @@
 node_modules
 bower_components
 npm-debug.log
+
+.vs/

jobs/Backend/Task/Chain of Responsibility/CNB.cs

@@ -0,0 +1,28 @@
+using ExchangeRateUpdater.CNB;
+using ExchangeRateUpdater.Decorator;
+using ExchangeRateUpdater.Models;
+using ExchangeRateUpdater.Singleton;
+
+namespace ExchangeRateUpdater.Chain_of_Responsibility
+{
+    public class CNB : Handler
+    {
+        private LoadRates _load;
+
+        public CNB() => _load = new APICall(new DataClean(new LoadData()));
+
+        public CNB(LoadRates loadRates) => _load = loadRates;
+
+        public override ExchangeRate GetExchangeRate(Currency currency)
+        {
+            bool result = _load.Load("").Result;
+
+            if (DB.GetInstance().TryGetValue(currency.Code, out Rate rate))
+            {
+                return new ExchangeRate(currency, new Currency("CZK"), rate.rate);
+            }
+
+            return null;
+        }
+    }
+}

jobs/Backend/Task/Chain of Responsibility/Handler.cs

@@ -0,0 +1,11 @@
+namespace ExchangeRateUpdater.Chain_of_Responsibility
+{
+    public abstract class Handler : IHandler
+    {
+        protected IHandler? next;
+
+        public void SetNext(Handler next) => this.next = next;
+
+        public abstract ExchangeRate GetExchangeRate(Currency currency);
+    }
+}

jobs/Backend/Task/Chain of Responsibility/IHandler.cs

@@ -0,0 +1,7 @@
+namespace ExchangeRateUpdater.Chain_of_Responsibility
+{
+    public interface IHandler
+    {
+        ExchangeRate GetExchangeRate(Currency currency);
+    }
+}

jobs/Backend/Task/Chain of Responsibility/Redis.cs

@@ -0,0 +1,26 @@
+using ExchangeRateUpdater.Models;
+using ExchangeRateUpdater.Singleton;
+
+namespace ExchangeRateUpdater.Chain_of_Responsibility
+{
+    public class Redis : Handler
+    {
+        private DB _rates;
+
+        public Redis() => _rates = DB.GetInstance();
+
+        public override ExchangeRate GetExchangeRate(Currency currency)
+        {
+            if (_rates.TryGetValue(currency.Code, out Rate rate))
+            {
+                return new ExchangeRate(currency, new Currency("CZK"), rate.rate);
+            }
+            else if(!_rates.IsEmpty())
+            {
+                return null;
+            }
+
+            return next.GetExchangeRate(currency);
+        }
+    }
+}

jobs/Backend/Task/Decorator/APICall.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Net.Http;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using ExchangeRateUpdater.Decorator;
+using ExchangeRateUpdater.Helpers;
+
+namespace ExchangeRateUpdater.CNB
+{
+    public class APICall : LoadRates
+    {
+        string path;
+
+        readonly HttpClient client;
+        StringBuilder result;
+
+        HttpResponseMessage response;
+
+        public APICall(ILoadRates loadRates) : base(loadRates)
+        {
+            path = ConfigHelper.GetCnbApiPath();
+            client = new();
+        }
+
+        public APICall(ILoadRates loadRates, HttpClient httpClient) : base(loadRates)
+        {
+            path = ConfigHelper.GetCnbApiPath();
+            client = httpClient;
+        }
+
+        public override async Task<bool> Load(string data)
+        {
+            try
+            {
+                if (Regex.IsMatch(data, @"^([0-2]?[0-9]|3[0-1])\.(0[1-9]|1[0-2])\.\d{4}$"))
+                {
+                    path += $"?date = {data}";
+                }
+            }
+            catch(ArgumentNullException e)
+            {
+                Console.WriteLine($"Wrong input: '{e.Message}'.");
+            }
+
+            return await load();
+        }
+
+        private async Task<bool> load()
+        {
+            result = new();
+
+            try
+            {
+                response = await client.GetAsync(path);
+
+                if (response.IsSuccessStatusCode)
+                {
+                    result.Append(await response.Content.ReadAsStringAsync());
+                }
+                else
+                {
+                    throw new Exception("No data from the resource");
+                }
+            }
+            catch(HttpRequestException)
+            {
+                throw;
+            }
+
+            return await wrapper.Load(result.ToString());
+        }
+    }
+}

jobs/Backend/Task/Decorator/DataClean.cs

@@ -0,0 +1,46 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+
+namespace ExchangeRateUpdater.Decorator
+{
+    public class DataClean : LoadRates
+    {
+        private string _line;
+        private StringBuilder _correctLines;
+
+        public DataClean(ILoadRates wrapper) : base(wrapper) { }
+
+        public override async Task<bool> Load(string data)
+        {
+            _correctLines = new();
+
+            try
+            {
+                using (StringReader reader = new(data))
+                {
+                    while ((_line = reader.ReadLine()) != null)
+                    {
+                        if (Regex.IsMatch(_line, @"^[A-Za-z ]+\|[A-Za-z ]+\|(1|100|1000)\|[A-Z]{3}\|\d+\.\d+$"))
+                        {
+                            _correctLines.AppendLine(_line);
+                        }
+                    }
+                }
+            }
+            catch (ArgumentNullException)
+            {
+                throw;
+            }
+
+            if (_correctLines.Length == 0)
+            {
+                throw new Exception("No data to be added to the data base");
+            }
+
+            return await wrapper.Load(_correctLines.ToString());
+        }
+    }
+}

jobs/Backend/Task/Decorator/ILoadRates.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace ExchangeRateUpdater.Decorator
+{
+    public interface ILoadRates
+    {
+        public Task<bool> Load(string data);
+    }
+}

jobs/Backend/Task/Decorator/LoadData.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Globalization;
+using System.IO;
+using System.Threading.Tasks;
+using ExchangeRateUpdater.Models;
+using ExchangeRateUpdater.Singleton;
+
+namespace ExchangeRateUpdater.Decorator
+{
+    public class LoadData : ILoadRates
+    {
+        private string _line;
+        private DB _rates;
+
+        public LoadData() => _rates = DB.GetInstance();
+
+        public async Task<bool> Load(string data)
+        {
+            try
+            {
+                using (StringReader reader = new(data))
+                {
+                    while ((_line = reader.ReadLine()) != null)
+                    {
+                        string[] list = _line.Split('|');
+                        _rates.Add(list[3], new Rate(list[0], list[1], Convert.ToInt16(list[2]), list[3], Convert.ToDecimal(list[4], CultureInfo.InvariantCulture)));
+                    }
+                }
+            }
+            catch (IndexOutOfRangeException)
+            {
+                throw;
+            }
+            catch (ArgumentNullException)
+            {
+                throw;
+            }
+            catch (FormatException)
+            {
+                throw;
+            }
+
+            return !_rates.IsEmpty();
+        }
+    }
+}

jobs/Backend/Task/Decorator/LoadRates.cs

@@ -0,0 +1,13 @@
+using System.Threading.Tasks;
+
+namespace ExchangeRateUpdater.Decorator
+{
+    public abstract class LoadRates : ILoadRates
+    {
+        protected ILoadRates wrapper;
+
+        protected LoadRates(ILoadRates wrapper) => this.wrapper = wrapper;
+
+        public abstract Task<bool> Load(string data);
+    }
+}

jobs/Backend/Task/ExchangeRateProvider.cs

@@ -1,5 +1,5 @@
 using System.Collections.Generic;
-using System.Linq;
+using ExchangeRateUpdater.Chain_of_Responsibility;
 
 namespace ExchangeRateUpdater
 {
@@ -11,9 +11,32 @@ public class ExchangeRateProvider
         /// 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 Handler handler;
+        private List<ExchangeRate> _exchangeRates;
+
+        public ExchangeRateProvider()
+        {
+            _exchangeRates = new();
+
+            handler = new Redis();
+            Chain_of_Responsibility.CNB cnb = new();
+            handler.SetNext(cnb);
+        }
+
         public IEnumerable<ExchangeRate> GetExchangeRates(IEnumerable<Currency> currencies)
         {
-            return Enumerable.Empty<ExchangeRate>();
+            foreach (Currency currency in currencies)
+            {
+                ExchangeRate exchangeRate = handler.GetExchangeRate(currency);
+
+                if(exchangeRate is not null)
+                { 
+                    _exchangeRates.Add(exchangeRate);
+                }
+            }
+
+            return _exchangeRates;
         }
     }
 }

jobs/Backend/Task/ExchangeRateUpdater.csproj

@@ -5,4 +5,18 @@
     <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Remove="ExchangeRateProvider.cs~RF143d8135.TMP" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNet.WebApi.Client" Version="6.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="appsettings.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
 </Project>

jobs/Backend/Task/ExchangeRateUpdater.sln

@@ -1,10 +1,12 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.25123.0
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36414.22 d17.14
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExchangeRateUpdater", "ExchangeRateUpdater.csproj", "{7B2695D6-D24C-4460-A58E-A10F08550CE0}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TestExchangeRateUpdater", "..\TestExchangeRateUpdater\TestExchangeRateUpdater.csproj", "{3401A3CA-1731-4126-A7AA-D28D430DA0E2}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -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
+		{3401A3CA-1731-4126-A7AA-D28D430DA0E2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3401A3CA-1731-4126-A7AA-D28D430DA0E2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3401A3CA-1731-4126-A7AA-D28D430DA0E2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3401A3CA-1731-4126-A7AA-D28D430DA0E2}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {2D09087A-D6FC-436D-BBF9-1CE6413B2831}
+	EndGlobalSection
 EndGlobal

jobs/Backend/Task/Helpers/ConfigHelper.cs

@@ -0,0 +1,18 @@
+using System.IO;
+using System.Text.Json;
+
+namespace ExchangeRateUpdater.Helpers
+{
+    internal static class ConfigHelper
+    {
+        public static string GetCnbApiPath()
+        {
+            var json = File.ReadAllText("appsettings.json");
+            using var doc = JsonDocument.Parse(json);
+            return doc.RootElement
+                      .GetProperty("CNB")
+                      .GetProperty("ApiPath")
+                      .GetString()!;
+        }
+    }
+}