Check cache for currency rate before run async util

RhSolutions.AddIn/AddIn/RhSolutionsFunctions.cs

@@ -2,6 +2,8 @@
 using System.Runtime.Versioning;
 #endif
 
+using Microsoft.Extensions.Caching.Memory;
+
 namespace RhSolutions.AddIn;
 
 #if !NET472
@@ -190,29 +192,33 @@ public class RhSolutionsFunctions
     public static object КУРСЕВРО([ExcelArgument(Name = "ДАТА", Description = "Дата в формате Excel (необязательно)")] double dateField)
     {
         ICurrencyClient currencyClient = RhSolutionsAddIn.ServiceProvider.GetRequiredService<ICurrencyClient>();
+        IMemoryCache memoryCache = RhSolutionsAddIn.ServiceProvider.GetRequiredService<IMemoryCache>();
+        DateTime date = dateField == 0 ? DateTime.Today : DateTime.FromOADate(dateField);
 
-        if (ExcelAsyncUtil.Run(nameof(КУРСЕВРО), dateField, delegate
+        if (!memoryCache.TryGetValue(date, out decimal exchangeRate))
         {
-            DateTime date = dateField == 0 ? DateTime.Today : DateTime.FromOADate(dateField);
+            var result = ExcelAsyncUtil.Run(nameof(КУРСЕВРО), dateField, delegate
-            var exchangeRate = currencyClient.GetCurrencyCourse(date)
-                .GetAwaiter()
-                .GetResult();
-
-            return exchangeRate ?? -1m;
-        }) is not decimal requestResult)
-        {
-            return "Загрузка...";
-        }
-        else
-        {
-            if (requestResult < 0)
             {
-                return ExcelError.ExcelErrorNA;
+                var requestResult = currencyClient.GetCurrencyCourse(date)
+                    .GetAwaiter()
+                    .GetResult();
+
+                return requestResult ?? -1m;
+            });
+
+            if (result is not decimal)
+            {
+                return "Загрузка...";
             }
             else
             {
-                return Math.Round(requestResult, 2);
+                exchangeRate = (decimal)result; 
+                var cacheEntryOptions = new MemoryCacheEntryOptions()
+                    .SetSlidingExpiration(TimeSpan.FromHours(1));
+                memoryCache.Set(date, exchangeRate, cacheEntryOptions);
             }
         }
+
+        return exchangeRate < 0 ? ExcelError.ExcelErrorNA : exchangeRate;
     }
 }

RhSolutions.AddIn/Services/CurrencyClient.cs

@@ -1,5 +1,4 @@
-using Microsoft.Extensions.Caching.Memory;
+using System.Net;
-using System.Net;
 using System.Net.Http;
 using System.Threading.Tasks;
 using System.Xml.Linq;
@@ -9,43 +8,34 @@ namespace RhSolutions.Services;
 public class CurrencyClient : ICurrencyClient
 {
     private readonly HttpClient _httpClient;
-    private readonly IMemoryCache _memoryCache;
+    private const string _requestAddress = @"https://www.cbr.ru/scripts/XML_daily.asp?date_req=";
-    private const string requestAddress = @"https://www.cbr.ru/scripts/XML_daily.asp?date_req=";
     public HttpStatusCode StatusCode { get; private set; }
 
-    public CurrencyClient(HttpClient httpClient, IMemoryCache memoryCache)
+    public CurrencyClient(HttpClient httpClient)
     {
         _httpClient = httpClient;
-        _memoryCache = memoryCache;
     }
 
     public async Task<decimal?> GetCurrencyCourse(DateTime date)
     {
-        if (!_memoryCache.TryGetValue(date, out decimal? exchangeRate))
+        string request = $"{_requestAddress}{date.Date:dd/MM/yyyy}";
+        HttpResponseMessage response = await _httpClient.GetAsync(request);
+        try
         {
-            string request = $"{requestAddress}{date.Date:dd/MM/yyyy}";
+            response.EnsureSuccessStatusCode();
-            HttpResponseMessage response = await _httpClient.GetAsync(request);
+            string xml = await response.Content.ReadAsStringAsync();
-            try
+            XElement valCourses = XElement.Parse(xml);
-            {
-                response.EnsureSuccessStatusCode();
-                string xml = await response.Content.ReadAsStringAsync();
-                XElement valCourses = XElement.Parse(xml);
-                exchangeRate = decimal.Parse(valCourses.Elements("Valute")
-                    .Where(e => e.Element("Name").Value == "Евро")
-                    .FirstOrDefault()
-                    .Element("Value").Value);
-                return exchangeRate;
-            }
-            catch
-            {
-                StatusCode = response.StatusCode;
-                exchangeRate = null;
-            }
 
-            var cacheEntryOptions = new MemoryCacheEntryOptions()
+            decimal? exchangeRate = decimal.Parse(valCourses.Elements("Valute")
-                .SetSlidingExpiration(TimeSpan.FromHours(1));
+                .Where(e => e.Element("Name").Value == "Евро")
-            _memoryCache.Set(date, exchangeRate, cacheEntryOptions);
+                .FirstOrDefault()
+                .Element("Value").Value);
+            return exchangeRate;
+        }
+        catch
+        {
+            StatusCode = response.StatusCode;
+            return null;
         }
-        return exchangeRate;
     }
 }