Start working on http handshake support

Reactor/Networking/ModList.cs

@@ -21,7 +21,7 @@ namespace Reactor.Networking
             return _mapByNetId![netId];
         }
 
-        internal static void Update()
+        internal static ISet<Mod> Update()
         {
             var i = (uint) 0;
 
@@ -37,6 +37,8 @@ namespace Reactor.Networking
 
             _mapById = Current.ToDictionary(mod => mod.Id, mod => mod);
             _mapByNetId = Current.ToDictionary(mod => mod.NetId, mod => mod);
+
+            return Current;
         }
     }
 }

Reactor/Networking/Patches/ClientPatches.cs

@@ -165,7 +165,7 @@ namespace Reactor.Networking.Patches
 
             public static void Postfix(ref Il2CppStructArray<byte> __result)
             {
-                ModList.Update();
+                var mods = ModList.Update();
 
                 var handshake = new MessageWriter(1000);
 
@@ -173,7 +173,7 @@ namespace Reactor.Networking.Patches
 
                 ModdedHandshakeC2S.Serialize(
                     handshake,
-                    ModList.Current!.Count
+                    mods.Count
                 );
 
                 __result = handshake.ToByteArray(true);

Reactor/Networking/Patches/HttpPatches.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Linq;
+using System.Text;
+using HarmonyLib;
+using UnhollowerBaseLib;
+using UnityEngine.Networking;
+
+namespace Reactor.Networking.Patches;
+
+[HarmonyPatch]
+internal static class HttpPatches
+{
+    public const int Version = 1;
+
+    public static string BuildHeader()
+    {
+        var stringBuilder = new StringBuilder();
+
+        stringBuilder.Append(Version);
+        stringBuilder.Append(";");
+
+        var mods = ModList.Update().Where(m => m.Side == PluginSide.Both).OrderBy(m => m.Id, StringComparer.Ordinal).ToArray();
+
+        stringBuilder.Append(mods.Length);
+
+        foreach (var mod in mods)
+        {
+            stringBuilder.Append(";");
+            stringBuilder.Append(mod.Id);
+            stringBuilder.Append("=");
+            stringBuilder.Append(mod.Version);
+        }
+
+        return stringBuilder.ToString();
+    }
+
+    [HarmonyPatch(typeof(UnityWebRequest), nameof(UnityWebRequest.Get), typeof(string))]
+    [HarmonyPatch(typeof(UnityWebRequest), nameof(UnityWebRequest.Post), typeof(string), typeof(string))]
+    [HarmonyPatch(typeof(UnityWebRequest), nameof(UnityWebRequest.Put), typeof(string), typeof(Il2CppStructArray<byte>))]
+    [HarmonyPostfix]
+    public static void UnityWebRequestPatch(UnityWebRequest __result)
+    {
+        var path = __result.uri.AbsolutePath;
+
+        if (path == "/api/games")
+        {
+            __result.SetRequestHeader("Client-Mods", BuildHeader());
+        }
+    }
+
+    [HarmonyPatch(typeof(HttpMatchmakerManager._CoRequestGameList_d__7), nameof(HttpMatchmakerManager._CoRequestGameList_d__7.MoveNext))]
+    public static class CoRequestGameListPatch
+    {
+        public static void Prefix(HttpMatchmakerManager._CoRequestGameList_d__7 __instance)
+        {
+            if (__instance.__1__state == 2)
+            {
+                if (HttpUtils.IsSuccess(__instance._request_5__3.responseCode))
+                {
+                    var responseHeader = __instance._request_5__3.GetResponseHeader("Client-Mods-Processed");
+                    if (responseHeader == null)
+                    {
+                        AmongUsClient.Instance.LastDisconnectReason = DisconnectReasons.Custom;
+                        AmongUsClient.Instance.LastCustomDisconnect = "This region doesn't support modded handshake.\nThe lobbies shown may not be compatible with your current mods.\nFor more info see https://reactor.gg/handshake";
+                        DisconnectPopup.Instance.Show();
+                    }
+                }
+            }
+        }
+    }
+}