From 3ed1c598a752e792b55ce3d863c89059eed013ee Mon Sep 17 00:00:00 2001
From: Bobby Bonestell <rbonestell@gmail.com>
Date: Sat, 8 Feb 2025 13:28:59 -0700
Subject: [PATCH] WIP implementation of dynamic port configuration for YARP
 implementation

---
 FUNC/Node.cs    |  4 ++++
 FUNC/Program.cs | 42 +++++++++++++++++++++++++++++++++---------
 FUNC/Shared.cs  |  8 ++++++++
 3 files changed, 45 insertions(+), 9 deletions(-)
 create mode 100644 FUNC/Shared.cs

diff --git a/FUNC/Node.cs b/FUNC/Node.cs
index 6550417..b3540cd 100644
--- a/FUNC/Node.cs
+++ b/FUNC/Node.cs
@@ -27,6 +27,10 @@ public static async Task<NodeStatus> Get(string name)
                 var endpointAddressToken = config.GetValue("EndpointAddress");
                 string endpointAddress = endpointAddressToken?.Value<string>() ?? ":0";
                 port = int.Parse(endpointAddress[(endpointAddress.IndexOf(":") + 1)..]);
+                if (name == "algorand")
+                    Shared.AlgoPort = port;
+                else if (name == "voi")
+                    Shared.VoiPort = port;
             }
 
             string sc = string.Empty;
diff --git a/FUNC/Program.cs b/FUNC/Program.cs
index a4d14a2..6b3f3aa 100644
--- a/FUNC/Program.cs
+++ b/FUNC/Program.cs
@@ -1,6 +1,6 @@
 using FUNC;
 using Microsoft.Net.Http.Headers;
-//using Yarp.ReverseProxy.Transforms;
+using Yarp.ReverseProxy.Transforms;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -18,14 +18,38 @@
     });
 });
 builder.Services.AddReverseProxy()
-    .LoadFromConfig(builder.Configuration.GetSection("ReverseProxy"));
-    //.AddTransforms(transformBuilderContext =>
-    //{
-    //    transformBuilderContext.AddRequestTransform(transformContext =>
-    //    {
-    //        // TODO: change port on destination address based on node configuration value
-    //    });
-    //});
+    .LoadFromConfig(builder.Configuration.GetSection("ReverseProxy"))
+    .AddTransforms(transformBuilderContext =>
+    {
+        transformBuilderContext.AddRequestTransform(transformContext =>
+        {
+            // Get the original host
+            var ogPort = transformContext.HttpContext.Request.Host.Port;
+            var destPort = 8080;
+
+            // Check if it's a request to the legacy site
+            if (ogPort == 1234) {
+                destPort = Shared.VoiPort;
+                
+            } else if (ogPort == 5678) {
+                // Algo Port
+                destPort = Shared.AlgoPort;
+            }
+
+            var destinationPrefix = transformContext.DestinationPrefix;
+            if (destinationPrefix != null)
+            {
+                var originalUri = new Uri(destinationPrefix);
+                var newUri = new UriBuilder(originalUri)
+                {
+                    Port = destPort
+                }.Uri;
+                transformContext.DestinationPrefix = newUri.ToString();
+            }
+            
+            return ValueTask.CompletedTask;
+        });
+    });
 
 var app = builder.Build();
 
diff --git a/FUNC/Shared.cs b/FUNC/Shared.cs
new file mode 100644
index 0000000..163f805
--- /dev/null
+++ b/FUNC/Shared.cs
@@ -0,0 +1,8 @@
+namespace FUNC
+{
+    public static class Shared
+    {
+        public static int AlgoPort { get; set; } = 8081;
+        public static int VoiPort { get; set; } = 8082;
+    }
+}