MVVM # Episode 3

using Messengers;
using Service;
using ViewModels;
using Views;

namespace Controllers
{
	/// <summary>
	/// The controller 'is' the application.
	/// Everything is controlled by this :
	/// it instantiates Views and ViewModels
	/// it retrieves and stores customers via services
	/// 
	/// But it does all this only in response to requests
	/// made by the ViewModels.
	/// 
	/// e.g. a ViewModel may request a list of customers
	/// e.g. a ViewModel may want to save changes to a customer
	/// 
	/// set up as a partial class for convenience
	/// </summary>
	public partial class CustomerController : BaseController, ICustomerController
	{
		private static ICustomerService CustomerService;

		#region Constructors
		/// <summary>
		/// Private constructor - we must pass a service to the constructor
		/// </summary>
		private CustomerController()
		{
		}

		/// <summary>
		/// The controller needs a reference to the service layer to enable it to make service calls
		/// </summary>
		/// <param name="customerService"></param>
		public CustomerController(ICustomerService customerService)
		{
			CustomerService = customerService;
		}
		#endregion


		#region Public Methods
		/// <summary>
		/// Main entry point of the Controller.
		/// Called once (from App.xaml.cs) this will initialise the application
		/// </summary>
		public void Start()
		{
			ShowViewCustomerSelection();
		}
		/// <summary>
		/// Edit the customer with the Id passed
		/// </summary>
		/// <param name="customerId">Id of the customer to be edited</param>
		/// <param name="daddy">The 'parent' ViewModel who will own the ViewModel that controls the Customer Edit</param>
		public void EditCustomer(int customerId, BaseViewModel daddy = null)
		{
			BaseView view = GetCustomerEditView(customerId, daddy);
			view.ShowInWindow(true, "Edit Customer");
		}

		/// <summary>
		/// A Customer has been selected to be edited
		/// </summary>
		/// <param name="data">The CustomerListItemViewData of the selected customer</param>
		/// <param name="daddy">The parent ViewModel</param>
		public void CustomerSelectedForEdit(CustomerListItemViewData data, BaseViewModel daddy = null)
		{
			// Check in case we get a null sent to us
			if (data != null && data.CustomerId != null)
			{
				NotificationResult result = Messenger.NotifyColleagues(MessageTypes.MSG_CUSTOMER_SELECTED_FOR_EDIT, data);
				if (result == NotificationResult.MessageNotRegistered || result == NotificationResult.MessageRegisteredNotHandled)
				{
					// Nothing was out there that handled our message, so we'll do it ourselves!
					EditCustomer((int)data.CustomerId, daddy);
				}
			}
		}
		#endregion

	}
}