Unavailable store item message (#31)

modules/ContentStore/Handler/Store.cs

@@ -106,12 +106,32 @@ public class Store : BotEventHandler
                 return;
             }
 
+            try
+            {
+                await PerformPurchase(mediaService, messageId);
+            }
+            catch (Exception e)
+            {
+                answer = "Товар недоступен";
+                await Bot.EditMessageTextAsync(Chat.Id,
+                    messageId,
+                    $"<b>{From.ToHtml()} попытался купить \"{storeItem.Name}\", но товара в наличии не оказалось.");
+                await AnswerQuery(query.Id, answer);
+                return;
+            }
+
             reputation = await _reputation.SetUserReputationAsync(Chat, From, reputation - storeItem.Price);
             await Bot.EditMessageTextAsync(Chat.Id, 
                 messageId, 
                 $"<b>{From.ToHtml()} ({reputation})</b> купил \"{storeItem.Name}\".",
                 ParseMode.Html);
+        }
 
+        await AnswerQuery(query.Id, answer);
+    }
+
+    private async Task PerformPurchase(IRandomMediaService mediaService, int messageId)
+    {
         var randomMedia = await mediaService!.GetRandomMediaAsync();
         var file = randomMedia.File;
 
@@ -136,9 +156,6 @@ public class Store : BotEventHandler
         }
     }
     
-        await AnswerQuery(query.Id, answer);
-    }
-    
     private bool TryGetMediaService(string name, out IRandomMediaService? mediaService)
     {
         mediaService = _provider.GetServices<IRandomMediaService>()