patch GalaxyNetServer to support context sync pending game code changes to make it public (#480)

1 files changed, 106 insertions, 0 deletions

diff --git a/src/SMAPI/Patches/GalaxyNetServerPatch.cs b/src/SMAPI/Patches/GalaxyNetServerPatch.cs
new file mode 100644
index 00000000..e01ac329
--- /dev/null
+++ b/src/SMAPI/Patches/GalaxyNetServerPatch.cs
@@ -0,0 +1,106 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Reflection;
+using Galaxy.Api;
+using Harmony;
+using StardewModdingAPI.Framework;
+using StardewModdingAPI.Framework.Patching;
+using StardewValley.Network;
+
+namespace StardewModdingAPI.Patches
+{
+    /// <summary>A Harmony patch to let SMAPI override <see cref="GalaxyNetServerPatch"/> methods.</summary>
+    internal class GalaxyNetServerPatch : IHarmonyPatch
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>SMAPI's implementation of the game's core multiplayer logic.</summary>
+        private static Lazy<SMultiplayer> Multiplayer;
+
+        /// <summary>The name of the internal GalaxyNetServer class.</summary>
+        private static readonly string ServerTypeName = $"StardewValley.SDKs.GalaxyNetServer, {Constants.GameAssemblyName}";
+
+        /// <summary>The method which sends an arbitrary message.</summary>
+        private static MethodInfo SendMessageMethod;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A unique name for this patch.</summary>
+        public string Name => $"{nameof(GalaxyNetServerPatch)}";
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="multiplayer">SMAPI's implementation of the game's core multiplayer logic.</param>
+        public GalaxyNetServerPatch(Func<SMultiplayer> multiplayer)
+        {
+            // init
+            GalaxyNetServerPatch.Multiplayer = new Lazy<SMultiplayer>(multiplayer);
+
+            // get server.sendMessage method
+            Type type = Type.GetType(GalaxyNetServerPatch.ServerTypeName);
+            if (type == null)
+                throw new InvalidOperationException($"Can't find type '{GalaxyNetServerPatch.ServerTypeName}'.");
+            GalaxyNetServerPatch.SendMessageMethod = type.GetMethod("sendMessage", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, new[] { typeof(GalaxyID), typeof(OutgoingMessage) }, null);
+            if (GalaxyNetServerPatch.SendMessageMethod == null)
+                throw new InvalidOperationException($"Can't find method 'sendMessage' on '{GalaxyNetServerPatch.ServerTypeName}'.");
+        }
+
+        /// <summary>Apply the Harmony patch.</summary>
+        /// <param name="harmony">The Harmony instance.</param>
+        public void Apply(HarmonyInstance harmony)
+        {
+            // override parseDataMessageFromClient
+            {
+                MethodInfo method = AccessTools.Method(Type.GetType($"StardewValley.SDKs.GalaxyNetServer, {Constants.GameAssemblyName}"), "onReceiveMessage");
+                MethodInfo prefix = AccessTools.Method(this.GetType(), nameof(GalaxyNetServerPatch.Prefix_GalaxyNetServer_OnReceiveMessage));
+                harmony.Patch(method, new HarmonyMethod(prefix), null);
+            }
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>The method to call instead of the <see cref="GalaxyNetServer.onReceiveMessage"/> method.</summary>
+        /// <param name="__instance">The instance being patched.</param>
+        /// <param name="peer">The Galaxy peer ID.</param>
+        /// <param name="messageStream">The data to process.</param>
+        /// <param name="___peers">The private <c>peers</c> field on the <paramref name="__instance"/> instance.</param>
+        /// <param name="___gameServer">The private <c>gameServer</c> field on the <paramref name="__instance"/> instance.</param>
+        /// <returns>Returns whether to execute the original method.</returns>
+        /// <remarks>This method must be static for Harmony to work correctly. See the Harmony documentation before renaming arguments.</remarks>
+        [SuppressMessage("ReSharper", "InconsistentNaming", Justification = "Argument names are defined by Harmony.")]
+        private static bool Prefix_GalaxyNetServer_OnReceiveMessage(Server __instance, GalaxyID peer, Stream messageStream, Bimap<long, ulong> ___peers, IGameServer ___gameServer)
+        {
+            SMultiplayer multiplayer = GalaxyNetServerPatch.Multiplayer.Value;
+
+            using (IncomingMessage message = new IncomingMessage())
+            using (BinaryReader reader = new BinaryReader(messageStream))
+            {
+                message.Read(reader);
+                multiplayer.OnServerProcessingMessage(message, outgoing => GalaxyNetServerPatch.SendMessageMethod.Invoke(__instance, new object[] { peer, outgoing }), () =>
+                {
+                    if (___peers.ContainsLeft(message.FarmerID) && (long)___peers[message.FarmerID] == (long)peer.ToUint64())
+                    {
+                        ___gameServer.processIncomingMessage(message);
+                    }
+                    else if (message.MessageType == StardewValley.Multiplayer.playerIntroduction)
+                    {
+                        NetFarmerRoot farmer = multiplayer.readFarmer(message.Reader);
+                        GalaxyID capturedPeer = new GalaxyID(peer.ToUint64());
+                        ___gameServer.checkFarmhandRequest(Convert.ToString(peer.ToUint64()), farmer, msg => GalaxyNetServerPatch.SendMessageMethod.Invoke(__instance, new object[] { capturedPeer, msg }), () => ___peers[farmer.Value.UniqueMultiplayerID] = capturedPeer.ToUint64());
+                    }
+                });
+            }
+
+            return false;
+        }
+    }
+}