// Harmony prefix to override entire method to potentially fix NRE

[HarmonyPatch(typeof(ChunkManager), nameof(ChunkManager.GetNextChunkToProvide))]
public class ChunkManagerPatches
{
    [HarmonyPrefix]
    public static bool Prefix(ChunkManager __instance, ref long __result)
    {
        int chunkPositionsCount = 0;

        lock (__instance.lockObject)
        {
            __instance.m_AllChunkPositions.list.CopyTo(__instance.allChunkPositionsCopy);
            chunkPositionsCount = __instance.m_AllChunkPositions.list.Count;
        }

        ChunkCluster chunkCache = __instance.m_World.ChunkCache;

        // added th== null check to preempt going through while loops and a stack trace to see where it possibly originates from
        if (chunkCache == null)
        {
            Log.Error($"ChunkManager::GetNextChunkToProvide - chunkCache == null here - why?? - Stacktrace: {System.Environment.StackTrace}"); // todo - find out why chunkCache would be null here, only seldomly
            __result = long.MaxValue;
            return false;
        }

        int num2 = 0;

        while (chunkCache != null && num2 < chunkPositionsCount)
        {
            long num3 = __instance.allChunkPositionsCopy[num2];

            if (WorldChunkCache.extractClrIdx(num3) == 0 && !chunkCache.ContainsChunkSync(num3))
            {
                __result = num3;
                return false;
            }

            num2++;
        }

        // chunkCache could be null here randomly - This line is where the NRE occurs.  Extra null check added here
        if (chunkCache != null && chunkCache.ChunkProvider != null && chunkCache.ChunkProvider.GetRequestedChunks() != null)
        {
            HashSetList<long> requestedChunks = chunkCache.ChunkProvider.GetRequestedChunks();
            lock (requestedChunks.list)
            {
                if (requestedChunks.list.Count > 0)
                {
                    long num4 = chunkCache.ChunkProvider.GetRequestedChunks().list[requestedChunks.list.Count - 1];
                    requestedChunks.Remove(num4);

                    __result = num4;
                    return false;
                }
            }
        }

        __result = long.MaxValue;

        // Don't process the original method
        return false;
    }
}