Created more proper NotFound exceptions

SchengenVisaApi/Infrastructure/Database/Locations/Repositories/Cities/CitiesRepository.cs

@@ -1,6 +1,7 @@
 using ApplicationLayer.Locations;
 using Domains.LocationDomain;
 using Infrastructure.Database.Generic;
+using Infrastructure.Database.Locations.Repositories.Cities.Exceptions;
 using Microsoft.EntityFrameworkCore;
 
 namespace Infrastructure.Database.Locations.Repositories.Cities;
@@ -12,4 +13,12 @@ public sealed class CitiesRepository(IGenericReader reader, IGenericWriter write
     {
         return base.LoadDomain().Include(c => c.Country);
     }
-}
+
+    ///<inheritdoc cref="ICitiesRepository.GetByNameAsync"/>
+    /// <exception cref="CityNotFoundByNameException">city with provided name and country not found</exception>
+    public async Task<City> GetByNameAsync(string name, string countryName, CancellationToken cancellationToken)
+    {
+        var result = await LoadDomain().Where(c => c.Name == name && c.Country.Name == countryName).SingleOrDefaultAsync(cancellationToken);
+        return result ?? throw new CityNotFoundByNameException(name, countryName);
+    }
+}

SchengenVisaApi/Infrastructure/Database/Locations/Repositories/Cities/Exceptions/CityNotFoundByNameException.cs

@@ -0,0 +1,11 @@
+using Domains.LocationDomain;
+using Infrastructure.Database.GeneralExceptions;
+
+namespace Infrastructure.Database.Locations.Repositories.Cities.Exceptions
+{
+    /// Exception to throw when city cannot be found by its name and its country name
+    /// <param name="name">Name of the city</param>
+    /// <param name="countryName">name of the city's country</param>
+    public class CityNotFoundByNameException(string name, string countryName)
+        : EntityNotFoundException<City>($"{name} with country {countryName} not found.");
+}