Adding authentication and authorization flow

MainProject/Services/UserService.cs

@@ -0,0 +1,59 @@
+
+using System.Collections;
+using BasicDotnetTemplate.MainProject.Core.Database;
+using BasicDotnetTemplate.MainProject.Models.Database.SqlServer;
+using Microsoft.EntityFrameworkCore;
+
+namespace BasicDotnetTemplate.MainProject.Services;
+
+public interface IUserService
+{
+    Task<User?> GetUserByUsernameAndPassword(string username, string password);
+}
+
+public class UserService : BaseService, IUserService
+{
+
+    public UserService(
+        IConfiguration configuration,
+        SqlServerContext sqlServerContext
+    ) : base(configuration, sqlServerContext)
+    { }
+
+    private IQueryable<User> GetUsers()
+    {
+        return this._sqlServerContext.Users.Where(x => !x.IsDeleted);
+    }
+
+    private IQueryable<User> GetUserByUsername(string username)
+    {
+        return this._sqlServerContext.Users
+            .Where(x =>
+                !x.IsDeleted &&
+                String.Equals(x.Username, username, StringComparison.CurrentCultureIgnoreCase)
+            );
+    }
+
+
+    public async Task<User?> GetUserByUsernameAndPassword(string username, string password)
+    {
+        User? user = null;
+
+        try
+        {
+            user = await this.GetUserByUsername(username).FirstOrDefaultAsync();
+            if (user != null)
+            {
+                var encryptedPassword = user.PasswordHash;
+                Console.WriteLine(encryptedPassword);
+            }
+        }
+        catch (Exception exception)
+        {
+            Console.WriteLine(exception.Message);
+        }
+
+        return user;
+    }
+}
+