Refactor IStream to single generic parameter interface

Refactored IStream and related classes to use a single generic parameter (IStream<TIn>), removing the internal TCurrent type from the public API. Updated all builder interfaces, handlers, and usages to match the new signature. Introduced IBranchInfo for branch metadata, and updated GetBranches() to return IBranchInfo instances. This simplifies the stream abstraction and improves API encapsulation.

Author: eneshoxha

src/Cortex.Streams.Mediator/Behaviors/StreamEmittingCommandBehavior.cs

@@ -14,7 +14,7 @@ namespace Cortex.Streams.Mediator.Behaviors
     public class StreamEmittingCommandBehavior<TCommand, TResult> : ICommandPipelineBehavior<TCommand, TResult>
         where TCommand : ICommand<TResult>
     {
-        private readonly IStream<CommandExecutionEvent<TCommand, TResult>, CommandExecutionEvent<TCommand, TResult>> _stream;
+        private readonly IStream<CommandExecutionEvent<TCommand, TResult>> _stream;
         private readonly bool _emitBeforeExecution;
         private readonly bool _emitAfterExecution;
 
@@ -25,7 +25,7 @@ public class StreamEmittingCommandBehavior<TCommand, TResult> : ICommandPipeline
         /// <param name="emitBeforeExecution">If true, emit an event before command execution.</param>
         /// <param name="emitAfterExecution">If true, emit an event after command execution.</param>
         public StreamEmittingCommandBehavior(
-            IStream<CommandExecutionEvent<TCommand, TResult>, CommandExecutionEvent<TCommand, TResult>> stream,
+            IStream<CommandExecutionEvent<TCommand, TResult>> stream,
             bool emitBeforeExecution = false,
             bool emitAfterExecution = true)
         {

src/Cortex.Streams.Mediator/Behaviors/StreamEmittingNotificationBehavior.cs

@@ -18,7 +18,7 @@ namespace Cortex.Streams.Mediator.Behaviors
     public class StreamEmittingNotificationBehavior<TNotification> : INotificationPipelineBehavior<TNotification>
         where TNotification : INotification
     {
-        private readonly IStream<NotificationEvent<TNotification>, NotificationEvent<TNotification>> _stream;
+        private readonly IStream<NotificationEvent<TNotification>> _stream;
         private readonly bool _emitBeforeHandling;
         private readonly bool _emitAfterHandling;
 
@@ -29,7 +29,7 @@ public class StreamEmittingNotificationBehavior<TNotification> : INotificationPi
         /// <param name="emitBeforeHandling">If true, emit an event before notification handling.</param>
         /// <param name="emitAfterHandling">If true, emit an event after notification handling.</param>
         public StreamEmittingNotificationBehavior(
-            IStream<NotificationEvent<TNotification>, NotificationEvent<TNotification>> stream,
+            IStream<NotificationEvent<TNotification>> stream,
             bool emitBeforeHandling = false,
             bool emitAfterHandling = true)
         {

src/Cortex.Streams.Mediator/DependencyInjection/ServiceCollectionExtensions.cs

@@ -22,7 +22,7 @@ public static class ServiceCollectionExtensions
         /// <returns>The service collection for chaining.</returns>
         public static IServiceCollection AddStreamEmittingNotificationHandler<TNotification>(
             this IServiceCollection services,
-            Func<IServiceProvider, IStream<TNotification, TNotification>> streamFactory,
+            Func<IServiceProvider, IStream<TNotification>> streamFactory,
             Action<TNotification, Exception> errorHandler = null)
             where TNotification : INotification
         {
@@ -47,7 +47,7 @@ public static IServiceCollection AddStreamEmittingNotificationHandler<TNotificat
         /// <returns>The service collection for chaining.</returns>
         public static IServiceCollection AddTransformingStreamNotificationHandler<TNotification, TStreamInput>(
             this IServiceCollection services,
-            Func<IServiceProvider, IStream<TStreamInput, TStreamInput>> streamFactory,
+            Func<IServiceProvider, IStream<TStreamInput>> streamFactory,
             Func<TNotification, TStreamInput> transformer,
             Action<TNotification, Exception> errorHandler = null)
             where TNotification : INotification

src/Cortex.Streams.Mediator/Handlers/StreamBackedStreamQueryHandler.cs

@@ -17,15 +17,15 @@ namespace Cortex.Streams.Mediator.Handlers
     public abstract class StreamBackedStreamQueryHandler<TQuery, TResult> : IStreamQueryHandler<TQuery, TResult>
         where TQuery : IStreamQuery<TResult>
     {
-        private readonly IStream<TResult, TResult> _stream;
+        private readonly IStream<TResult> _stream;
         private readonly int _channelCapacity;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="StreamBackedStreamQueryHandler{TQuery, TResult}"/> class.
         /// </summary>
         /// <param name="stream">The Cortex Stream to read data from.</param>
         /// <param name="channelCapacity">The capacity of the internal channel buffer. Default is 100.</param>
-        protected StreamBackedStreamQueryHandler(IStream<TResult, TResult> stream, int channelCapacity = 100)
+        protected StreamBackedStreamQueryHandler(IStream<TResult> stream, int channelCapacity = 100)
         {
             _stream = stream ?? throw new ArgumentNullException(nameof(stream));
             _channelCapacity = channelCapacity;

src/Cortex.Streams.Mediator/Handlers/StreamEmittingNotificationHandler.cs

@@ -13,7 +13,7 @@ namespace Cortex.Streams.Mediator.Handlers
     public class StreamEmittingNotificationHandler<TNotification> : INotificationHandler<TNotification>
         where TNotification : INotification
     {
-        private readonly IStream<TNotification, TNotification> _stream;
+        private readonly IStream<TNotification> _stream;
         private readonly Action<TNotification, Exception> _errorHandler;
 
         /// <summary>
@@ -22,7 +22,7 @@ public class StreamEmittingNotificationHandler<TNotification> : INotificationHan
         /// <param name="stream">The stream to emit notifications to.</param>
         /// <param name="errorHandler">Optional handler for errors during emission.</param>
         public StreamEmittingNotificationHandler(
-            IStream<TNotification, TNotification> stream,
+            IStream<TNotification> stream,
             Action<TNotification, Exception> errorHandler = null)
         {
             _stream = stream ?? throw new ArgumentNullException(nameof(stream));
@@ -62,7 +62,7 @@ public async Task Handle(TNotification notification, CancellationToken cancellat
     public class TransformingStreamNotificationHandler<TNotification, TStreamInput> : INotificationHandler<TNotification>
         where TNotification : INotification
     {
-        private readonly IStream<TStreamInput, TStreamInput> _stream;
+        private readonly IStream<TStreamInput> _stream;
         private readonly Func<TNotification, TStreamInput> _transformer;
         private readonly Action<TNotification, Exception> _errorHandler;
 
@@ -73,7 +73,7 @@ public class TransformingStreamNotificationHandler<TNotification, TStreamInput>
         /// <param name="transformer">A function to transform notifications into stream input.</param>
         /// <param name="errorHandler">Optional handler for errors during emission.</param>
         public TransformingStreamNotificationHandler(
-            IStream<TStreamInput, TStreamInput> stream,
+            IStream<TStreamInput> stream,
             Func<TNotification, TStreamInput> transformer,
             Action<TNotification, Exception> errorHandler = null)
         {

src/Cortex.Streams/Abstractions/IBranchInfo.cs

@@ -0,0 +1,15 @@
+namespace Cortex.Streams.Abstractions
+{
+    /// <summary>
+    /// Provides information about a branch in the stream processing pipeline.
+    /// This is a non-generic interface that allows accessing branch metadata
+    /// without exposing internal type parameters.
+    /// </summary>
+    public interface IBranchInfo
+    {
+        /// <summary>
+        /// Gets the name of the branch.
+        /// </summary>
+        string BranchName { get; }
+    }
+}

src/Cortex.Streams/Abstractions/IFanOutBuilder.cs

@@ -126,6 +126,6 @@ public interface IFanOutBuilder<TIn, TCurrent>
         /// </summary>
         /// <returns>The built stream instance ready to be started.</returns>
         /// <exception cref="InvalidOperationException">Thrown when no sinks have been configured.</exception>
-        IStream<TIn, TCurrent> Build();
+        IStream<TIn> Build();
     }
 }

src/Cortex.Streams/Abstractions/ISinkBuilder.cs

@@ -4,13 +4,13 @@
     /// Provides a method to build the stream after adding a sink.
     /// </summary>
     /// <typeparam name="TIn">The type of the initial input to the stream.</typeparam>
-    /// <typeparam name="TCurrent">The current type of data in the stream.</typeparam>
+    /// <typeparam name="TCurrent">The current type of data in the stream (internal use only).</typeparam>
     public interface ISinkBuilder<TIn, TCurrent>
     {
         /// <summary>
         /// Builds the stream and returns a stream instance that can be started and stopped.
         /// </summary>
         /// <returns>A stream instance.</returns>
-        IStream<TIn, TCurrent> Build();
+        IStream<TIn> Build();
     }
 }

src/Cortex.Streams/Abstractions/IStream.cs

@@ -1,13 +1,13 @@
 using Cortex.States;
-using Cortex.Streams.Operators;
+using Cortex.Streams.Abstractions;
 using Cortex.Streams.Performance;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 
 namespace Cortex.Streams
 {
-    public interface IStream<TIn, TCurrent>
+    public interface IStream<TIn>
     {
         /// <summary>
         /// Start the stream processing.
@@ -66,7 +66,7 @@ public interface IStream<TIn, TCurrent>
 
         StreamStatuses GetStatus();
 
-        IReadOnlyDictionary<string, BranchOperator<TCurrent>> GetBranches();
+        IReadOnlyDictionary<string, IBranchInfo> GetBranches();
 
         TStateStore GetStateStoreByName<TStateStore>(string name) where TStateStore : IDataStore;
         IEnumerable<TStateStore> GetStateStoresByType<TStateStore>() where TStateStore : IDataStore;

src/Cortex.Streams/Abstractions/IStreamBuilder.cs

@@ -107,7 +107,7 @@ public interface IStreamBuilder<TIn, TCurrent>
         /// Builds the stream
         /// </summary>
         /// <returns></returns>
-        IStream<TIn, TCurrent> Build();
+        IStream<TIn> Build();
 
 
         /// <summary>