undead-universal-patch-il2cpp/BasePatches/PhotonPatchEvents.cs

using HarmonyLib;
using System;
using System.ComponentModel;
using System.Reflection;

namespace undead_universal_patch_il2cpp.Patches
{
    [HarmonyPatch]
    public class ConnectToRecNetPatchEvent
    {
        static readonly string TargetTypeName = "RecNet.Core";
        static readonly string TargetMethodName = "ConnectToRecNet";
        static readonly string Description = "Photon/Hile Patch event method"; // It's convenient. Could patch at a different time. But this part was easy.
        static readonly MethodInfo connectMethod = AccessTools.Method(AccessTools.TypeByName(TargetTypeName), TargetMethodName);
        
        static bool Prepare()
        {
            if (connectMethod == null)
            {
                Plugin.Log.LogWarning($"'{Description}' disabled. The method for this patch was not found.");
                return false;
            }

            Plugin.Log.LogInfo($"'{Description}' succeeded validation.");
            return true;
        }
        static MethodBase TargetMethod() => connectMethod;
        static void Prefix()
        {
            if (PhotonConfig.PatchPhotonIds.Value) PhotonPatch.Patch();
            if (GenericConfig.HilePatch.Value) HilePatch.Patch();
        }
    }

    public class PhotonPatch
    {
        public static void Patch()
        {
            Type photonNetworkType = AccessTools.TypeByName("PhotonNetwork");
            Type serverSettingsType = AccessTools.TypeByName("ServerSettings");

            if (photonNetworkType == null || serverSettingsType == null)
            {
                Plugin.Log.LogError("Cannot patch Photon: PhotonNetwork or ServerSettings types were not found. Is this build supported?");
                return;
            }

            // The property PhotonServerSettings (which should be a field) didn't appear when I didn't specify `Runtime`. Not sure why. But this works.
            PropertyInfo photonServerSettingsProperty = photonNetworkType.GetRuntimeProperty("PhotonServerSettings");
            object serverSettings = photonServerSettingsProperty.GetValue(serverSettingsType);

            PropertyInfo appIdField = serverSettingsType.GetRuntimeProperty("AppID");
            PropertyInfo voiceAppIdField = serverSettingsType.GetRuntimeProperty("VoiceAppID");

            appIdField.SetValue(serverSettings, PhotonConfig.AppID.Value);
            voiceAppIdField.SetValue(serverSettings, PhotonConfig.VoiceAppID.Value);

            Plugin.Log.LogInfo("Photon patch succeeded.");
        }
    }
}