Adding service layer testing (#151)

src/Core/Service/Service.Auth/LoginService.cs

@@ -0,0 +1,34 @@
+using Domain.Entities;
+using Domain.Exceptions;
+using Infrastructure.PasswordHashing;
+using Infrastructure.Repository.Auth;
+
+namespace Service.Auth;
+
+public class LoginService(
+    IAuthRepository authRepo,
+    IPasswordInfrastructure passwordInfrastructure
+) : ILoginService
+{
+
+    public async Task<UserAccount> LoginAsync(string username, string password)
+    {
+        // Attempt lookup by username
+        var user = await authRepo.GetUserByUsernameAsync(username);
+
+        // the user was not found
+        if (user is null)
+            throw new UnauthorizedException("Invalid username or password.");
+
+        // @todo handle expired passwords
+        var activeCred = await authRepo.GetActiveCredentialByUserAccountIdAsync(user.UserAccountId);
+
+        if (activeCred is null)
+            throw new UnauthorizedException("Invalid username or password.");
+
+        if (!passwordInfrastructure.Verify(password, activeCred.Hash))
+            throw new UnauthorizedException("Invalid username or password.");
+
+        return user;
+    }
+}