From 2a2de8a95f894b5c80cb6a8b35c496c74d3133c9 Mon Sep 17 00:00:00 2001
From: Joel Oliveira <joelfilipeoliveira@gmail.com>
Date: Wed, 14 Oct 2020 15:25:39 +0100
Subject: [PATCH] feat: allow middlewares to be registered at the beginning

---
 ...IConsumerMiddlewareConfigurationBuilder.cs | 19 ++++++++++++++++++
 .../ConsumerMiddlewareConfigurationBuilder.cs | 20 ++++++++++++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/KafkaFlow.Abstractions/Configuration/IConsumerMiddlewareConfigurationBuilder.cs b/src/KafkaFlow.Abstractions/Configuration/IConsumerMiddlewareConfigurationBuilder.cs
index 47f499e70..676d04f84 100644
--- a/src/KafkaFlow.Abstractions/Configuration/IConsumerMiddlewareConfigurationBuilder.cs
+++ b/src/KafkaFlow.Abstractions/Configuration/IConsumerMiddlewareConfigurationBuilder.cs
@@ -19,6 +19,16 @@ public interface IConsumerMiddlewareConfigurationBuilder
         IConsumerMiddlewareConfigurationBuilder Add<T>(Factory<T> factory)
             where T : class, IMessageMiddleware;
 
+        /// <summary>
+        /// Registers a middleware at the beginning of the middleware list
+        /// The middleware will run before other middlewares that already have been registered
+        /// </summary>
+        /// <param name="factory">A factory to create the instance</param>
+        /// <typeparam name="T">A class that implements the <see cref="IMessageMiddleware"/></typeparam>
+        /// <returns></returns>
+        IConsumerMiddlewareConfigurationBuilder AddAtBeginning<T>(Factory<T> factory)
+            where T : class, IMessageMiddleware;
+
         /// <summary>
         /// Registers a middleware
         /// </summary>
@@ -26,5 +36,14 @@ IConsumerMiddlewareConfigurationBuilder Add<T>(Factory<T> factory)
         /// <returns></returns>
         IConsumerMiddlewareConfigurationBuilder Add<T>()
             where T : class, IMessageMiddleware;
+
+        /// <summary>
+        /// Registers a middleware at the beginning of the middleware list 
+        /// The middleware will run before other middlewares that already have been registered
+        /// </summary>
+        /// <typeparam name="T">A class that implements the <see cref="IMessageMiddleware"/></typeparam>
+        /// <returns></returns>
+        IConsumerMiddlewareConfigurationBuilder AddAtBeginning<T>()
+            where T : class, IMessageMiddleware;
     }
 }
diff --git a/src/KafkaFlow/Configuration/ConsumerMiddlewareConfigurationBuilder.cs b/src/KafkaFlow/Configuration/ConsumerMiddlewareConfigurationBuilder.cs
index 9dbfaef7c..1629e1b9a 100644
--- a/src/KafkaFlow/Configuration/ConsumerMiddlewareConfigurationBuilder.cs
+++ b/src/KafkaFlow/Configuration/ConsumerMiddlewareConfigurationBuilder.cs
@@ -21,13 +21,31 @@ public IConsumerMiddlewareConfigurationBuilder Add<T>(Factory<T> factory) where
             return this;
         }
 
+        public IConsumerMiddlewareConfigurationBuilder AddAtBeginning<T>(Factory<T> factory) where T : class, IMessageMiddleware
+        {
+            this.middlewaresFactories.Insert(0, factory);
+            return this;
+        }
+
         public IConsumerMiddlewareConfigurationBuilder Add<T>() where T : class, IMessageMiddleware
         {
-            this.DependencyConfigurator.AddTransient<T>();
+            this.RegisterType<T>();
             this.middlewaresFactories.Add(resolver => resolver.Resolve<T>());
             return this;
         }
 
+        public IConsumerMiddlewareConfigurationBuilder AddAtBeginning<T>() where T : class, IMessageMiddleware
+        {
+            this.RegisterType<T>();
+            this.middlewaresFactories.Insert(0, resolver => resolver.Resolve<T>());
+            return this;
+        }        
+
         public MiddlewareConfiguration Build() => new MiddlewareConfiguration(this.middlewaresFactories);
+
+        private void RegisterType<T>() where T : class, IMessageMiddleware
+        {
+            this.DependencyConfigurator.AddTransient<T>();
+        }
     }
 }