Update repository, seed and service layers

BusinessLayer/Services/IService.cs

@@ -1,15 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace BusinessLayer.Services
-{
-    public interface IService<T>
-        where T : class
-    {
-        IEnumerable<T> GetAll(int? limit, int? offset);
-        T? GetById(Guid id);
-        void Add(T entity);
-        void Update(T entity);
-        void Delete(Guid id);
-    }
-}

BusinessLayer/Services/IUserService.cs

@@ -2,9 +2,9 @@ using DataAccessLayer.Entities;
 
 namespace BusinessLayer.Services
 {
-    public interface IUserService : IService<UserAccount>
+    public interface IUserService
     {
-        UserAccount? GetByUsername(string username);
-        UserAccount? GetByEmail(string email);
+        Task<IEnumerable<UserAccount>> GetAllAsync(int? limit = null, int? offset = null);
+        Task<UserAccount?> GetByIdAsync(Guid id);
     }
 }

BusinessLayer/Services/UserService.cs

@@ -1,51 +1,18 @@
-using DataAccessLayer;
 using DataAccessLayer.Entities;
 using DataAccessLayer.Repositories;
 
 namespace BusinessLayer.Services
 {
-    public class UserService : IUserService
+    public class UserService(IUserAccountRepository repository) : IUserService
     {
-        private readonly IUserAccountRepository _userAccountRepository;
-
-        public UserService(IUserAccountRepository userAccountRepository)
+        public async Task<IEnumerable<UserAccount>> GetAllAsync(int? limit = null, int? offset = null)
         {
-            _userAccountRepository = userAccountRepository;
+            return await repository.GetAll(limit, offset);
         }
 
-        public IEnumerable<UserAccount> GetAll(int? limit, int? offset)
+        public async Task<UserAccount?> GetByIdAsync(Guid id)
         {
-            return _userAccountRepository.GetAll(limit, offset);
-        }
-
-        public UserAccount? GetById(Guid id)
-        {
-            return _userAccountRepository.GetById(id);
-        }
-
-        public UserAccount? GetByUsername(string username)
-        {
-            return _userAccountRepository.GetByUsername(username);
-        }
-
-        public UserAccount? GetByEmail(string email)
-        {
-            return _userAccountRepository.GetByEmail(email);
-        }
-
-        public void Add(UserAccount userAccount)
-        {
-            _userAccountRepository.Add(userAccount);
-        }
-
-        public void Update(UserAccount userAccount)
-        {
-            _userAccountRepository.Update(userAccount);
-        }
-
-        public void Delete(Guid id)
-        {
-            _userAccountRepository.Delete(id);
+            return await repository.GetById(id);
         }
     }
 }

DALTests/UserAccountRepositoryTests.cs

@@ -6,10 +6,10 @@ namespace DALTests
 {
     public class UserAccountRepositoryTests
     {
-        private readonly IUserAccountRepository _repository = new UserAccountRepository();
+        private readonly IUserAccountRepository _repository = new InMemoryUserAccountRepository();
 
         [Fact]
-        public void Add_ShouldInsertUserAccount()
+        public async Task Add_ShouldInsertUserAccount()
         {
             // Arrange
             var userAccount = new UserAccount
@@ -24,8 +24,8 @@ namespace DALTests
             };
 
             // Act
-            _repository.Add(userAccount);
-            var retrievedUser = _repository.GetById(userAccount.UserAccountId);
+            await _repository.Add(userAccount);
+            var retrievedUser = await _repository.GetById(userAccount.UserAccountId);
 
             // Assert
             Assert.NotNull(retrievedUser);
@@ -33,7 +33,7 @@ namespace DALTests
         }
 
         [Fact]
-        public void GetById_ShouldReturnUserAccount()
+        public async Task GetById_ShouldReturnUserAccount()
         {
             // Arrange
             var userId = Guid.NewGuid();
@@ -47,10 +47,10 @@ namespace DALTests
                 CreatedAt = DateTime.UtcNow,
                 DateOfBirth = new DateTime(1985, 5, 15),
             };
-            _repository.Add(userAccount);
+            await _repository.Add(userAccount);
 
             // Act
-            var retrievedUser = _repository.GetById(userId);
+            var retrievedUser = await _repository.GetById(userId);
 
             // Assert
             Assert.NotNull(retrievedUser);
@@ -58,7 +58,7 @@ namespace DALTests
         }
 
         [Fact]
-        public void Update_ShouldModifyUserAccount()
+        public async Task Update_ShouldModifyUserAccount()
         {
             // Arrange
             var userAccount = new UserAccount
@@ -71,12 +71,12 @@ namespace DALTests
                 CreatedAt = DateTime.UtcNow,
                 DateOfBirth = new DateTime(1992, 3, 10),
             };
-            _repository.Add(userAccount);
+            await _repository.Add(userAccount);
 
             // Act
             userAccount.FirstName = "Updated";
-            _repository.Update(userAccount);
-            var updatedUser = _repository.GetById(userAccount.UserAccountId);
+            await _repository.Update(userAccount);
+            var updatedUser = await _repository.GetById(userAccount.UserAccountId);
 
             // Assert
             Assert.NotNull(updatedUser);
@@ -84,7 +84,7 @@ namespace DALTests
         }
 
         [Fact]
-        public void Delete_ShouldRemoveUserAccount()
+        public async Task Delete_ShouldRemoveUserAccount()
         {
             // Arrange
             var userAccount = new UserAccount
@@ -97,18 +97,18 @@ namespace DALTests
                 CreatedAt = DateTime.UtcNow,
                 DateOfBirth = new DateTime(1995, 7, 20),
             };
-            _repository.Add(userAccount);
+            await _repository.Add(userAccount);
 
             // Act
-            _repository.Delete(userAccount.UserAccountId);
-            var deletedUser = _repository.GetById(userAccount.UserAccountId);
+            await _repository.Delete(userAccount.UserAccountId);
+            var deletedUser = await _repository.GetById(userAccount.UserAccountId);
 
             // Assert
             Assert.Null(deletedUser);
         }
 
         [Fact]
-        public void GetAll_ShouldReturnAllUserAccounts()
+        public async Task GetAll_ShouldReturnAllUserAccounts()
         {
             // Arrange
             var user1 = new UserAccount
@@ -131,11 +131,11 @@ namespace DALTests
                 CreatedAt = DateTime.UtcNow,
                 DateOfBirth = new DateTime(1992, 2, 2),
             };
-            _repository.Add(user1);
-            _repository.Add(user2);
+            await _repository.Add(user1);
+            await _repository.Add(user2);
 
             // Act
-            var allUsers = _repository.GetAll(null, null);
+            var allUsers = await _repository.GetAll(null, null);
 
             // Assert
             Assert.NotNull(allUsers);
@@ -143,7 +143,7 @@ namespace DALTests
         }
 
         [Fact]
-        public void GetAll_WithPagination_ShouldRespectLimit()
+        public async Task GetAll_WithPagination_ShouldRespectLimit()
         {
             // Arrange
             var users = new List<UserAccount>
@@ -182,25 +182,99 @@ namespace DALTests
 
             foreach (var user in users)
             {
-                _repository.Add(user);
+                await _repository.Add(user);
             }
 
             // Act
-            var page = _repository.GetAll(2, 0).ToList();
+            var page = (await _repository.GetAll(2, 0)).ToList();
 
             // Assert
             Assert.Equal(2, page.Count);
         }
 
         [Fact]
-        public void GetAll_WithPagination_ShouldValidateArguments()
+        public async Task GetAll_WithPagination_ShouldValidateArguments()
         {
-            Assert.Throws<ArgumentOutOfRangeException>(() =>
-                _repository.GetAll(0, 0).ToList()
+            await Assert.ThrowsAsync<ArgumentOutOfRangeException>(async () =>
+                (await _repository.GetAll(0, 0)).ToList()
             );
-            Assert.Throws<ArgumentOutOfRangeException>(() =>
-                _repository.GetAll(1, -1).ToList()
+            await Assert.ThrowsAsync<ArgumentOutOfRangeException>(async () =>
+                (await _repository.GetAll(1, -1)).ToList()
             );
         }
     }
+
+    internal class InMemoryUserAccountRepository : IUserAccountRepository
+    {
+        private readonly Dictionary<Guid, UserAccount> _store = new();
+
+        public Task Add(UserAccount userAccount)
+        {
+            if (userAccount.UserAccountId == Guid.Empty)
+            {
+                userAccount.UserAccountId = Guid.NewGuid();
+            }
+            _store[userAccount.UserAccountId] = Clone(userAccount);
+            return Task.CompletedTask;
+        }
+
+        public Task<UserAccount?> GetById(Guid id)
+        {
+            _store.TryGetValue(id, out var user);
+            return Task.FromResult(user is null ? null : Clone(user));
+        }
+
+        public Task<IEnumerable<UserAccount>> GetAll(int? limit, int? offset)
+        {
+            if (limit.HasValue && limit.Value <= 0) throw new ArgumentOutOfRangeException(nameof(limit));
+            if (offset.HasValue && offset.Value < 0) throw new ArgumentOutOfRangeException(nameof(offset));
+
+            var query = _store.Values
+                .OrderBy(u => u.Username)
+                .Select(Clone);
+
+            if (offset.HasValue) query = query.Skip(offset.Value);
+            if (limit.HasValue) query = query.Take(limit.Value);
+
+            return Task.FromResult<IEnumerable<UserAccount>>(query.ToList());
+        }
+
+        public Task Update(UserAccount userAccount)
+        {
+            if (!_store.ContainsKey(userAccount.UserAccountId)) return Task.CompletedTask;
+            _store[userAccount.UserAccountId] = Clone(userAccount);
+            return Task.CompletedTask;
+        }
+
+        public Task Delete(Guid id)
+        {
+            _store.Remove(id);
+            return Task.CompletedTask;
+        }
+
+        public Task<UserAccount?> GetByUsername(string username)
+        {
+            var user = _store.Values.FirstOrDefault(u => u.Username == username);
+            return Task.FromResult(user is null ? null : Clone(user));
+        }
+
+        public Task<UserAccount?> GetByEmail(string email)
+        {
+            var user = _store.Values.FirstOrDefault(u => u.Email == email);
+            return Task.FromResult(user is null ? null : Clone(user));
+        }
+
+        private static UserAccount Clone(UserAccount u) => new()
+        {
+            UserAccountId = u.UserAccountId,
+            Username = u.Username,
+            FirstName = u.FirstName,
+            LastName = u.LastName,
+            Email = u.Email,
+            CreatedAt = u.CreatedAt,
+            UpdatedAt = u.UpdatedAt,
+            DateOfBirth = u.DateOfBirth,
+            Timer = u.Timer is null ? null : (byte[])u.Timer.Clone(),
+        };
+    }
 }

DBSeed/UserSeeder.cs

@@ -12,7 +12,6 @@ namespace DBSeed
 
     internal class UserSeeder : ISeeder
     {
-        private UserAccountRepository _userAccountRepository = new UserAccountRepository();
         
         
         private static readonly IReadOnlyList<(
@@ -133,15 +132,17 @@ namespace DBSeed
             foreach (var (firstName, lastName) in SeedNames)
             {
                // create the user in the database
-               var ua = new UserAccount
+               var userAccountId = Guid.NewGuid();
+               await AddUserAccountAsync(connection, new UserAccount
                {
+                   UserAccountId = userAccountId,
                    FirstName = firstName,
                    LastName = lastName,
                    Email = $"{firstName}.{lastName}@thebiergarten.app",
                    Username = $"{firstName[0]}.{lastName}",
                    DateOfBirth = GenerateDateOfBirth(rng)
-               };
-
+               });
+               createdUsers++;
 
                // add user credentials
                 if (!await HasUserCredentialAsync(connection, userAccountId))
@@ -167,6 +168,21 @@ namespace DBSeed
             Console.WriteLine($"Added {createdVerifications} user verifications.");
         }
 
+        private static async Task AddUserAccountAsync(SqlConnection connection, UserAccount ua)
+        {
+            await using var command = new SqlCommand("usp_CreateUserAccount", connection);
+            command.CommandType = CommandType.StoredProcedure;
+
+            command.Parameters.Add("@UserAccountId", SqlDbType.UniqueIdentifier).Value = ua.UserAccountId;
+            command.Parameters.Add("@Username", SqlDbType.NVarChar, 100).Value = ua.Username;
+            command.Parameters.Add("@FirstName", SqlDbType.NVarChar, 100).Value = ua.FirstName;
+            command.Parameters.Add("@LastName", SqlDbType.NVarChar, 100).Value = ua.LastName;
+            command.Parameters.Add("@Email", SqlDbType.NVarChar, 256).Value = ua.Email;
+            command.Parameters.Add("@DateOfBirth", SqlDbType.Date).Value = ua.DateOfBirth;
+
+            await command.ExecuteNonQueryAsync();
+        }
+
         private static string GeneratePasswordHash(string pwd)
         {
             byte[] salt = RandomNumberGenerator.GetBytes(16);

DataAccessLayer/Repositories/IRepository.cs

@@ -1,20 +0,0 @@
-
-
-using Microsoft.Data.SqlClient;
-
-namespace DataAccessLayer.Repositories
-{
-    public interface IRepository<T>
-        where T : class
-    {
-        void Add(T entity);
-
-        IEnumerable<T> GetAll(int? limit, int? offset);
-
-        T? GetById(Guid id);
-        void Update(T entity);
-        void Delete(Guid id);
-        
-        T MapToEntity(SqlDataReader entity);
-    }
-}

DataAccessLayer/Repositories/IUserAccountRepository.cs

@@ -2,9 +2,14 @@ using DataAccessLayer.Entities;
 
 namespace DataAccessLayer.Repositories
 {
-    public interface IUserAccountRepository : IRepository<UserAccount>
+    public interface IUserAccountRepository
     {
-        UserAccount? GetByUsername(string username);
-        UserAccount? GetByEmail(string email);
+        Task Add(UserAccount userAccount);
+        Task<UserAccount?> GetById(Guid id);
+        Task<IEnumerable<UserAccount>> GetAll(int? limit, int? offset);
+        Task Update(UserAccount userAccount);
+        Task Delete(Guid id);
+        Task<UserAccount?> GetByUsername(string username);
+        Task<UserAccount?> GetByEmail(string email);
     }
 }

DataAccessLayer/Repositories/Repository.cs

@@ -0,0 +1,24 @@
+using DataAccessLayer.Sql;
+using Microsoft.Data.SqlClient;
+
+namespace DataAccessLayer.Repositories
+{
+    public abstract class Repository<T>(ISqlConnectionFactory connectionFactory)
+        where T : class
+    {
+        protected async Task<SqlConnection> CreateConnection()
+        {
+            var connection = connectionFactory.CreateConnection();
+            await connection.OpenAsync();
+            return connection;
+        }
+
+        public abstract Task Add(T entity);
+        public abstract Task<IEnumerable<T>> GetAll(int? limit, int? offset);
+        public abstract Task<T?> GetById(Guid id);
+        public abstract Task Update(T entity);
+        public abstract Task Delete(Guid id);
+
+        protected abstract T MapToEntity(SqlDataReader reader);
+    }
+}

DataAccessLayer/Repositories/UserAccountRepository.cs

@@ -1,139 +1,59 @@
 using DataAccessLayer.Entities;
+using DataAccessLayer.Sql;
 using Microsoft.Data.SqlClient;
+using System.Data;
 
 namespace DataAccessLayer.Repositories
 {
-    public class UserAccountRepository : IUserAccountRepository
+    public class UserAccountRepository(ISqlConnectionFactory connectionFactory)
+        : Repository<UserAccount>(connectionFactory), IUserAccountRepository
     {
-        private readonly string _connectionString = Environment.GetEnvironmentVariable("DB_CONNECTION_STRING")
-                                                    ?? throw new InvalidOperationException(
-                                                        "The connection string is not set in the environment variables."
-                                                    );
-
-        public void Add(UserAccount userAccount)
+        public override async Task Add(UserAccount userAccount)
         {
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new("usp_CreateUserAccount", connection);
-            command.CommandType = System.Data.CommandType.StoredProcedure;
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_CreateUserAccount", connection);
+            command.CommandType = CommandType.StoredProcedure;
 
-            command.Parameters.AddWithValue(
-                "@UserAccountId",
-                userAccount.UserAccountId
-            );
-            command.Parameters.AddWithValue("@Username", userAccount.Username);
-            command.Parameters.AddWithValue(
-                "@FirstName",
-                userAccount.FirstName
-            );
-            command.Parameters.AddWithValue("@LastName", userAccount.LastName);
-            command.Parameters.AddWithValue("@Email", userAccount.Email);
-            command.Parameters.AddWithValue(
-                "@DateOfBirth",
-                userAccount.DateOfBirth
-            );
-            connection.Open();
-            command.ExecuteNonQuery();
+            command.Parameters.Add("@UserAccountId", SqlDbType.UniqueIdentifier).Value = userAccount.UserAccountId;
+            command.Parameters.Add("@Username", SqlDbType.NVarChar, 100).Value = userAccount.Username;
+            command.Parameters.Add("@FirstName", SqlDbType.NVarChar, 100).Value = userAccount.FirstName;
+            command.Parameters.Add("@LastName", SqlDbType.NVarChar, 100).Value = userAccount.LastName;
+            command.Parameters.Add("@Email", SqlDbType.NVarChar, 256).Value = userAccount.Email;
+            command.Parameters.Add("@DateOfBirth", SqlDbType.Date).Value = userAccount.DateOfBirth;
+
+            await command.ExecuteNonQueryAsync();
         }
 
-        public UserAccount? GetById(Guid id)
+        public override async Task<UserAccount?> GetById(Guid id)
         {
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new(
-                "usp_GetUserAccountById",
-                connection
-            );
-            command.CommandType = System.Data.CommandType.StoredProcedure;
-            command.Parameters.AddWithValue("@UserAccountId", id);
-            connection.Open();
-
-            using SqlDataReader reader = command.ExecuteReader();
-            return reader.Read() ? MapToEntity(reader) : null;
-        }
-
-        public void Update(UserAccount userAccount)
-        {
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new("usp_UpdateUserAccount", connection);
-            command.CommandType = System.Data.CommandType.StoredProcedure;
-            command.Parameters.AddWithValue(
-                "@UserAccountId",
-                userAccount.UserAccountId
-            );
-            command.Parameters.AddWithValue("@Username", userAccount.Username);
-            command.Parameters.AddWithValue(
-                "@FirstName",
-                userAccount.FirstName
-            );
-            command.Parameters.AddWithValue("@LastName", userAccount.LastName);
-            command.Parameters.AddWithValue("@Email", userAccount.Email);
-            command.Parameters.AddWithValue(
-                "@DateOfBirth",
-                userAccount.DateOfBirth
-            );
-            command.Parameters.AddWithValue(
-                "@UserAccountId",
-                userAccount.UserAccountId
-            );
-            connection.Open();
-            command.ExecuteNonQuery();
-        }
-
-        public void Delete(Guid id)
-        {
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new("usp_DeleteUserAccount", connection);
-            command.CommandType = System.Data.CommandType.StoredProcedure;
-            command.Parameters.AddWithValue("@UserAccountId", id);
-            connection.Open();
-            command.ExecuteNonQuery();
-        }
-
-      
-        public IEnumerable<UserAccount> GetAll(int? limit, int? offset)
-        {
-            if (limit is <= 0)
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_GetUserAccountById", connection)
             {
-                throw new ArgumentOutOfRangeException(
-                    nameof(limit),
-                    "Limit must be greater than zero."
-                );
-            }
+                CommandType = CommandType.StoredProcedure
+            };
 
-            if (offset < 0)
-            {
-                throw new ArgumentOutOfRangeException(
-                    nameof(offset),
-                    "Offset cannot be negative."
-                );
-            }
+            command.Parameters.Add("@UserAccountId", SqlDbType.UniqueIdentifier).Value = id;
 
-            if (offset.HasValue && !limit.HasValue)
-            {
-                throw new ArgumentOutOfRangeException(
-                    nameof(offset),
-                    "Offset cannot be provided without a limit."
-                );
-            }
+            await using var reader = await command.ExecuteReaderAsync();
+            return await reader.ReadAsync() ? MapToEntity(reader) : null;
+        }
+
+        public override async Task<IEnumerable<UserAccount>> GetAll(int? limit, int? offset)
+        {
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_GetAllUserAccounts", connection);
+            command.CommandType = CommandType.StoredProcedure;
 
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new(
-                "usp_GetAllUserAccounts",
-                connection
-            );
-            command.CommandType = System.Data.CommandType.StoredProcedure;
             if (limit.HasValue)
-            {
-                command.Parameters.AddWithValue("@Limit", limit.Value);
-            }
-            if (offset.HasValue)
-            {
-                command.Parameters.AddWithValue("@Offset", offset.Value);
-            }
-            connection.Open();
+                command.Parameters.Add("@Limit", SqlDbType.Int).Value = limit.Value;
 
-            using SqlDataReader reader = command.ExecuteReader();
-            List<UserAccount> users = new();
-            while (reader.Read())
+            if (offset.HasValue)
+                command.Parameters.Add("@Offset", SqlDbType.Int).Value = offset.Value;
+
+            await using var reader = await command.ExecuteReaderAsync();
+            var users = new List<UserAccount>();
+
+            while (await reader.ReadAsync())
             {
                 users.Add(MapToEntity(reader));
             }
@@ -141,49 +61,73 @@ namespace DataAccessLayer.Repositories
             return users;
         }
 
-        public UserAccount? GetByUsername(string username)
+        public override async Task Update(UserAccount userAccount)
         {
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new(
-                "usp_GetUserAccountByUsername",
-                connection
-            );
-            command.CommandType = System.Data.CommandType.StoredProcedure;
-            command.Parameters.AddWithValue("@Username", username);
-            connection.Open();
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_UpdateUserAccount", connection);
+            command.CommandType = CommandType.StoredProcedure;
 
-            using SqlDataReader? reader = command.ExecuteReader();
-            return reader.Read() ? MapToEntity(reader) : null;
+            command.Parameters.Add("@UserAccountId", SqlDbType.UniqueIdentifier).Value = userAccount.UserAccountId;
+            command.Parameters.Add("@Username", SqlDbType.NVarChar, 100).Value = userAccount.Username;
+            command.Parameters.Add("@FirstName", SqlDbType.NVarChar, 100).Value = userAccount.FirstName;
+            command.Parameters.Add("@LastName", SqlDbType.NVarChar, 100).Value = userAccount.LastName;
+            command.Parameters.Add("@Email", SqlDbType.NVarChar, 256).Value = userAccount.Email;
+            command.Parameters.Add("@DateOfBirth", SqlDbType.Date).Value = userAccount.DateOfBirth;
+
+            await command.ExecuteNonQueryAsync();
         }
 
-        public UserAccount? GetByEmail(string email)
+        public override async Task Delete(Guid id)
         {
-            using SqlConnection connection = new(_connectionString);
-            using SqlCommand command = new(
-                "usp_GetUserAccountByEmail",
-                connection
-            );
-            command.CommandType = System.Data.CommandType.StoredProcedure;
-            command.Parameters.AddWithValue("@Email", email);
-            connection.Open();
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_DeleteUserAccount", connection);
+            command.CommandType = CommandType.StoredProcedure;
 
-            using SqlDataReader reader = command.ExecuteReader();
-            return reader.Read() ? MapToEntity(reader) : null;
+            command.Parameters.Add("@UserAccountId", SqlDbType.UniqueIdentifier).Value = id;
+            await command.ExecuteNonQueryAsync();
         }
 
-        public UserAccount MapToEntity(SqlDataReader reader)
+        public async Task<UserAccount?> GetByUsername(string username)
+        {
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_GetUserAccountByUsername", connection);
+            command.CommandType = CommandType.StoredProcedure;
+
+            command.Parameters.Add("@Username", SqlDbType.NVarChar, 100).Value = username;
+
+            await using var reader = await command.ExecuteReaderAsync();
+            return await reader.ReadAsync() ? MapToEntity(reader) : null;
+        }
+
+        public async Task<UserAccount?> GetByEmail(string email)
+        {
+            await using var connection = await CreateConnection();
+            await using var command = new SqlCommand("usp_GetUserAccountByEmail", connection);
+            command.CommandType = CommandType.StoredProcedure;
+
+            command.Parameters.Add("@Email", SqlDbType.NVarChar, 256).Value = email;
+
+            await using var reader = await command.ExecuteReaderAsync();
+            return await reader.ReadAsync() ? MapToEntity(reader) : null;
+        }
+
+        protected override UserAccount MapToEntity(SqlDataReader reader)
         {
             return new UserAccount
             {
-                UserAccountId = reader.GetGuid(0),
-                Username = reader.GetString(1),
-                FirstName = reader.GetString(2),
-                LastName = reader.GetString(3),
-                Email = reader.GetString(4),
-                CreatedAt = reader.GetDateTime(5),
-                UpdatedAt = reader.IsDBNull(6) ? null : reader.GetDateTime(6),
-                DateOfBirth = reader.GetDateTime(7),
-                Timer = reader.IsDBNull(8) ? null : (byte[])reader[8],
+                UserAccountId = reader.GetGuid(reader.GetOrdinal("UserAccountId")),
+                Username = reader.GetString(reader.GetOrdinal("Username")),
+                FirstName = reader.GetString(reader.GetOrdinal("FirstName")),
+                LastName = reader.GetString(reader.GetOrdinal("LastName")),
+                Email = reader.GetString(reader.GetOrdinal("Email")),
+                CreatedAt = reader.GetDateTime(reader.GetOrdinal("CreatedAt")),
+                UpdatedAt = reader.IsDBNull(reader.GetOrdinal("UpdatedAt"))
+                    ? null
+                    : reader.GetDateTime(reader.GetOrdinal("UpdatedAt")),
+                DateOfBirth = reader.GetDateTime(reader.GetOrdinal("DateOfBirth")),
+                Timer = reader.IsDBNull(reader.GetOrdinal("Timer"))
+                    ? null
+                    : (byte[])reader["Timer"]
             };
         }
     }

DataAccessLayer/Sql/DatabaseHelper.cs

@@ -1,41 +0,0 @@
-using System;
-using System.Data;
-using Microsoft.Data.SqlClient;
-
-namespace DataAccessLayer.Sql
-{
-    public class DatabaseHelper(string connectionString)
-    {
-        public void ExecuteRawSql(string query)
-        {
-            try
-            {
-                using var connection = new SqlConnection(
-                    connectionString
-                );
-                
-                connection.Open();
-
-                using var command = new SqlCommand(query, connection);
-                
-                command.CommandType = CommandType.Text;
-
-                using var reader = command.ExecuteReader();
-                
-                while (reader.Read())
-                {
-                    for (var i = 0; i < reader.FieldCount; i++)
-                    {
-                        Console.WriteLine(
-                            $"{reader.GetName(i)}: {reader.GetValue(i)}"
-                        );
-                    }
-                }
-            }
-            catch (Exception ex)
-            {
-                Console.WriteLine($"An error occurred: {ex.Message}");
-            }
-        }
-    }
-}

DataAccessLayer/Sql/ISqlConnectionFactory.cs

@@ -0,0 +1,9 @@
+using Microsoft.Data.SqlClient;
+
+namespace DataAccessLayer.Sql
+{
+    public interface ISqlConnectionFactory
+    {
+        SqlConnection CreateConnection();
+    }
+}

WebAPI/Controllers/UserController.cs

@@ -0,0 +1,26 @@
+using BusinessLayer.Services;
+using DataAccessLayer.Entities;
+using Microsoft.AspNetCore.Mvc;
+
+namespace WebAPI.Controllers
+{
+    [ApiController]
+    [Route("api/[controller]")]
+    public class UserController(IUserService userService) : ControllerBase
+    {
+        [HttpGet]
+        public async Task<ActionResult<IEnumerable<UserAccount>>> GetAll([FromQuery] int? limit, [FromQuery] int? offset)
+        {
+            var users = await userService.GetAllAsync(limit, offset);
+            return Ok(users);
+        }
+
+        [HttpGet("{id:guid}")]
+        public async Task<ActionResult<UserAccount>> GetById(Guid id)
+        {
+            var user = await userService.GetByIdAsync(id);
+            if (user is null) return NotFound();
+            return Ok(user);
+        }
+    }
+}

WebAPI/Controllers/UsersController.cs

@@ -1,107 +0,0 @@
-using BusinessLayer.Services;
-using DataAccessLayer.Entities;
-using Microsoft.AspNetCore.Mvc;
-
-namespace WebAPI.Controllers
-{
-    [ApiController]
-    [Route("api/users")]
-    public class UsersController : ControllerBase
-    {
-        private readonly IUserService _userService;
-
-        public UsersController(IUserService userService)
-        {
-            _userService = userService;
-        }
-
-        // all users
-        [HttpGet]
-        public IActionResult GetAllUsers(
-            [FromQuery] int? limit,
-            [FromQuery] int? offset
-        )
-        {
-            if (offset.HasValue && !limit.HasValue)
-            {
-                return BadRequest("Limit is required when offset is provided.");
-            }
-
-            if (limit.HasValue && limit <= 0)
-            {
-                return BadRequest("Limit must be greater than zero.");
-            }
-
-            if (offset.HasValue && offset < 0)
-            {
-                return BadRequest("Offset cannot be negative.");
-            }
-
-            var users = _userService.GetAll(limit, offset);
-            return Ok(users);
-        }
-
-        [HttpGet("{id:guid}")]
-        public IActionResult GetUserById(Guid id)
-        {
-            var user = _userService.GetById(id);
-            return user is null ? NotFound() : Ok(user);
-        }
-
-        [HttpGet("username/{username}")]
-        public IActionResult GetUserByUsername(string username)
-        {
-            var user = _userService.GetByUsername(username);
-            return user is null ? NotFound() : Ok(user);
-        }
-
-        [HttpGet("email/{email}")]
-        public IActionResult GetUserByEmail(string email)
-        {
-            var user = _userService.GetByEmail(email);
-            return user is null ? NotFound() : Ok(user);
-        }
-
-        [HttpPost]
-        public IActionResult CreateUser([FromBody] UserAccount userAccount)
-        {
-            if (userAccount.UserAccountId == Guid.Empty)
-            {
-                userAccount.UserAccountId = Guid.NewGuid();
-            }
-
-            _userService.Add(userAccount);
-            return CreatedAtAction(
-                nameof(GetUserById),
-                new { id = userAccount.UserAccountId },
-                userAccount
-            );
-        }
-
-        [HttpPut("{id:guid}")]
-        public IActionResult UpdateUser(
-            Guid id,
-            [FromBody] UserAccount userAccount
-        )
-        {
-            if (
-                userAccount.UserAccountId != Guid.Empty
-                && userAccount.UserAccountId != id
-            )
-            {
-                return BadRequest("UserAccountID does not match route id.");
-            }
-
-            userAccount.UserAccountId = id;
-            _userService.Update(userAccount);
-            return NoContent();
-        }
-
-        [HttpDelete("{id:guid}")]
-        public IActionResult DeleteUser(Guid id)
-        {
-            _userService.Delete(id);
-            return NoContent();
-        }
-    }
-}

WebAPI/Infrastructure/DefaultSqlConnectionFactory.cs

@@ -0,0 +1,25 @@
+using DataAccessLayer.Sql;
+using Microsoft.Data.SqlClient;
+
+namespace WebAPI.Infrastructure
+{
+    public class DefaultSqlConnectionFactory : ISqlConnectionFactory
+    {
+        private readonly string _connectionString;
+
+        public DefaultSqlConnectionFactory(IConfiguration configuration)
+        {
+            _connectionString =
+                Environment.GetEnvironmentVariable("DB_CONNECTION_STRING")
+                ?? configuration.GetConnectionString("Default")
+                ?? throw new InvalidOperationException(
+                    "Database connection string not configured. Set DB_CONNECTION_STRING env var or ConnectionStrings:Default."
+                );
+        }
+
+        public SqlConnection CreateConnection()
+        {
+            return new SqlConnection(_connectionString);
+        }
+    }
+}

WebAPI/Program.cs

@@ -1,6 +1,7 @@
 using BusinessLayer.Services;
-using DataAccessLayer;
 using DataAccessLayer.Repositories;
+using DataAccessLayer.Sql;
+using WebAPI.Infrastructure;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -8,9 +9,11 @@ builder.Services.AddControllers();
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 builder.Services.AddOpenApi();
+
+// Dependency Injection
+builder.Services.AddSingleton<ISqlConnectionFactory, DefaultSqlConnectionFactory>();
 builder.Services.AddScoped<IUserAccountRepository, UserAccountRepository>();
 builder.Services.AddScoped<IUserService, UserService>();
-
 var app = builder.Build();
 
 if (app.Environment.IsDevelopment())