using BeWo.Data;
using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel.Channels;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Xml;
using System.ServiceModel.Dispatcher;
using BeWo.Service.Core;
using BS.Shared.Extensions;
using BeWo.Service.ServiceUtils;
using BS.Shared.Attributes;
using static System.Windows.Forms.VisualStyles.VisualStyleElement.StartPanel;

namespace BeWo.Service.ServiceBehavior
{
	public class AdminMultitenancyContextInitializer : ICallContextInitializer
	{
		public void AfterInvoke(object pCorrelationState)
		{
			if (pCorrelationState is MultitenancyOperationContextExt)
			{
				OperationContext.Current.Extensions.Remove((MultitenancyOperationContextExt)pCorrelationState);
			}
		}

		public object BeforeInvoke(InstanceContext pInstanceContext, IClientChannel pChannel, Message pMessage)
		{
			string lTenant = null;

			// Hole Interface
			string lInterface = null;
			var segments = pChannel.LocalAddress.Uri.Segments;
			for (int i = 0; i < segments.Length; i++)
			{
				var seg = segments[i].Trim('/');

				if (seg.EndsWith(".svc"))
				{
					lInterface = "I" + seg.Substring(0, seg.Length - 4);
				}
			}

			if (string.IsNullOrWhiteSpace(lInterface))
			{
				throw new ArgumentException($"Zugriff verweigert. Interface unbekannt");
			}


			// Hole Methode
			string lMethod = pMessage.Properties[WebHttpDispatchOperationSelector.HttpOperationNamePropertyName] as string;
			if (string.IsNullOrWhiteSpace(lMethod))
			{
				throw new ArgumentException($"Zugriff verweigert. Methode unbekannt");
			}


			// RequireNoTenant
			var lTemp = ServiceHelper.GetCustomAttribute<RequireNoTenantAttribute>(lInterface, lMethod);
			if (lTemp is object)
			{
				return null;
			}

			// Hole tenant aus Query
			// Wird erstmal nicht benötigt. Per Header besser
			// Ungefähr auf einem Level wie Username
			//if (pMessage.Properties?.Via is Uri uri)
			//{
			//	var query = HttpUtility.ParseQueryString(uri.Query);
			//	var tenant = query["tenant"];

			//	lTenant = tenant;
			//}

			// Hole tenant aus Header
			if (string.IsNullOrWhiteSpace(lTenant))
			{
				var prop = (HttpRequestMessageProperty)pMessage.Properties[HttpRequestMessageProperty.Name];
				lTenant = prop?.Headers["tenant"];
			}

			// Wenn kein Tenant gefunden wird, 
			if (string.IsNullOrWhiteSpace(lTenant))
			{
				throw new ArgumentException($"Zugriff verweigert. Tenant (\'{lTenant}\') darf nicht leer sein.", nameof(lTenant));
			}

			var lExt = new MultitenancyOperationContextExt { Tenant = lTenant };
			OperationContext.Current.Extensions.Add(lExt);
			return lExt;
		}
	}
}