public class CustomerController : ODataController
{
    private readonly ICustomerService _customerService;
    private readonly IUnitOfWorkAsync _unitOfWorkAsync;

    public CustomerController(
        IUnitOfWorkAsync unitOfWorkAsync,
        ICustomerService customerService)
    {
        _unitOfWorkAsync = unitOfWorkAsync;
        _customerService = customerService;
    }

    // GET: odata/Customers
    [HttpGet]
    [Queryable]
    public IQueryable<Customer> GetCustomer()
    {
        return _customerService.Queryable();
    }

    // GET: odata/Customers(5)
    [Queryable]
    public SingleResult<Customer> GetCustomer([FromODataUri] string key)
    {
        return SingleResult.Create(_customerService.Queryable().Where(t => t.CustomerID == key));
    }

    // PUT: odata/Customers(5)
    public async Task<IHttpActionResult> Put(string key, Customer customer)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

        if (key != customer.CustomerID)
        {
            return BadRequest();
        }

        customer.TrackingState = TrackingState.Modified;
        _customerService.Update(customer);

        try
        {
            await _unitOfWorkAsync.SaveChangesAsync();
        }
        catch (DbUpdateConcurrencyException)
        {
            if (!CustomerExists(key))
            {
                return NotFound();
            }
            throw;
        }

        return Updated(customer);
    }

    // POST: odata/Customers
    public async Task<IHttpActionResult> Post(Customer customer)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

        customer.TrackingState = TrackingState.Added;
        _customerService.Insert(customer);

        try
        {
            await _unitOfWorkAsync.SaveChangesAsync();
        }
        catch (DbUpdateException)
        {
            if (CustomerExists(customer.CustomerID))
            {
                return Conflict();
            }
            throw;
        }

        return Created(customer);
    }

    //// PATCH: odata/Customers(5)
    [AcceptVerbs("PATCH", "MERGE")]
    public async Task<IHttpActionResult> Patch([FromODataUri] string key, Delta<Customer> patch)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

        Customer customer = await _customerService.FindAsync(key);

        if (customer == null)
        {
            return NotFound();
        }

        patch.Patch(customer);
        customer.TrackingState = TrackingState.Modified;

        try
        {
            await _unitOfWorkAsync.SaveChangesAsync();
        }
        catch (DbUpdateConcurrencyException)
        {
            if (!CustomerExists(key))
            {
                return NotFound();
            }
            throw;
        }

        return Updated(customer);
    }

    // DELETE: odata/Customers(5)
    public async Task<IHttpActionResult> Delete(string key)
    {
        Customer customer = await _customerService.FindAsync(key);

        if (customer == null)
        {
            return NotFound();
        }

        customer.TrackingState = TrackingState.Deleted;

        _customerService.Delete(customer);
        await _unitOfWorkAsync.SaveChangesAsync();

        return StatusCode(HttpStatusCode.NoContent);
    }

    // GET: odata/Customers(5)/CustomerDemographics
    [Queryable]
    public IQueryable<CustomerDemographic> GetCustomerDemographics([FromODataUri] string key)
    {
        return
            _customerService.Queryable()
                .Where(m => m.CustomerID == key)
                .SelectMany(m => m.CustomerDemographics);
    }

    // GET: odata/Customers(5)/Orders
    [Queryable]
    public IQueryable<Order> GetOrders([FromODataUri] string key)
    {
        return _customerService.Queryable().Where(m => m.CustomerID == key).SelectMany(m => m.Orders);
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            _unitOfWorkAsync.Dispose();
        }
        base.Dispose(disposing);
    }

    private bool CustomerExists(string key)
    {
        return _customerService.Query(e => e.CustomerID == key).Select().Any();
    }
}

public interface ICustomerService : IService<Customer>
{
    decimal CustomerOrderTotalByYear(string customerId, int year);
    IEnumerable<Customer> CustomersByCompany(string companyName);
    IEnumerable<CustomerOrder> GetCustomerOrder(string country);
}


public class CustomerService : Service<Customer>, ICustomerService
{
    private readonly IRepositoryAsync<Customer> _repository;

    public CustomerService(IRepositoryAsync<Customer> repository) : base(repository)
    {
        _repository = repository;
    }

    public decimal CustomerOrderTotalByYear(string customerId, int year)
    {
        // add any domain logic here
        return _repository.GetCustomerOrderTotalByYear(customerId, year);
    }

    public IEnumerable<Customer> CustomersByCompany(string companyName)
    {
        // add any domain logic here
        return _repository.CustomersByCompany(companyName);
    }

    public IEnumerable<CustomerOrder> GetCustomerOrder(string country)
    {
        // add any domain logic here
        return _repository.GetCustomerOrder(country);
    }

    public override void Insert(Customer entity)
    {
        // e.g. add any business logic here before inserting
        base.Insert(entity);
    }

    public override void Delete(object id)
    {
        // e.g. add business logic here before deleting
        base.Delete(id);
    }
}

public class UnityConfig
{
    private static Lazy<IUnityContainer> container = new Lazy<IUnityContainer>(() =>
    {
        var container = new UnityContainer();
        RegisterTypes(container);
        return container;
    });

    public static IUnityContainer GetConfiguredContainer()
    {
        return container.Value;
    }

    public static void RegisterTypes(IUnityContainer container)
    {
        container
            // Register DbContext instead of IDataDataContext, which is now obsolete.
            //.RegisterType<IDataContextAsync, NorthwindContext>(new PerRequestLifetimeManager())
            .RegisterType<DbContext, NorthwindContext>(new PerRequestLifetimeManager())
            .RegisterType<IUnitOfWorkAsync, UnitOfWork>(new PerRequestLifetimeManager())
            .RegisterType<IRepositoryAsync<Customer>, Repository<Customer>>()
            .RegisterType<IRepositoryAsync<Product>, Repository<Product>>()
            .RegisterType<IProductService, ProductService>()
            .RegisterType<ICustomerService, CustomerService>()
            .RegisterType<INorthwindStoredProcedures, NorthwindContext>(new PerRequestLifetimeManager())
            .RegisterType<IStoredProcedureService, StoredProcedureService>();
    }
}