How to make a Rust god mode plugin (damage immunity + full needs)

using System.Linq;
using System;
using System.Collections.Generic;
using Newtonsoft.Json;
using Oxide.Core;

namespace Oxide.Plugins
{
    [Info("God Mode", "RustPluginGenerator", "1.0.0")]
    [Description("Permission-based damage immunity that also keeps health, food and water full")]
    public class GodMode : RustPlugin
    {
        private const string PermUse = "godmode.use";

        private PluginConfig config;
        private readonly HashSet<ulong> protectedPlayers = new HashSet<ulong>();
        private Timer healTimer;

        private class PluginConfig
        {
            [JsonProperty("Permission")]
            public string Permission { get; set; } = PermUse;

            [JsonProperty("Top up interval in seconds")]
            public float HealInterval { get; set; } = 1f;
        }

        protected override void LoadDefaultConfig() => config = new PluginConfig();

        protected override void LoadConfig()
        {
            base.LoadConfig();
            try
            {
                config = Config.ReadObject<PluginConfig>();
                if (config == null) throw new Exception();
            }
            catch
            {
                PrintWarning("Configuration file is invalid, using defaults");
                LoadDefaultConfig();
            }
            SaveConfig();
        }

        protected override void SaveConfig() => Config.WriteObject(config);

        protected override void LoadDefaultMessages()
        {
            lang.RegisterMessages(new Dictionary<string, string>
            {
                ["Enabled"] = "God mode enabled. You are now immune to damage.",
                ["Disabled"] = "God mode disabled.",
                ["NoPermission"] = "You do not have permission to use this command."
            }, this);
        }

        private string Msg(string key, string userId = null, params object[] args)
            => string.Format(lang.GetMessage(key, this, userId), args);

        private void Init()
        {
            permission.RegisterPermission(config.Permission, this);
        }

        private void OnServerInitialized()
        {
            if (healTimer != null) healTimer.Destroy();
            healTimer = timer.Every(Math.Max(0.25f, config.HealInterval), TopUp);
        }

        private void Unload()
        {
            if (healTimer != null) healTimer.Destroy();
            healTimer = null;
            protectedPlayers.Clear();
        }

        [ChatCommand("god")]
        private void CmdGod(BasePlayer player, string command, string[] args)
        {
            if (player == null) return;

            if (!permission.UserHasPermission(player.UserIDString, config.Permission))
            {
                SendReply(player, Msg("NoPermission", player.UserIDString));
                return;
            }

            ulong id = player.userID.Get();
            if (protectedPlayers.Contains(id))
            {
                protectedPlayers.Remove(id);
                SendReply(player, Msg("Disabled", player.UserIDString));
                return;
            }

            protectedPlayers.Add(id);
            TopUp(player);
            SendReply(player, Msg("Enabled", player.UserIDString));
        }

        private object OnEntityTakeDamage(BasePlayer player, HitInfo hitInfo)
        {
            if (player == null || hitInfo == null) return null;
            if (!protectedPlayers.Contains(player.userID.Get())) return null;
            if (!permission.UserHasPermission(player.UserIDString, config.Permission)) return null;

            hitInfo.damageTypes?.ScaleAll(0f);
            return true;
        }

        private void OnPlayerDisconnected(BasePlayer player, string reason)
        {
            if (player == null) return;
            if (protectedPlayers.Remove(player.userID.Get()))
            {
                Puts($"{player.displayName} ({player.UserIDString}) lost god mode on disconnect");
            }
        }

        private void TopUp()
        {
            if (protectedPlayers.Count == 0) return;

            foreach (ulong id in new List<ulong>(protectedPlayers))
            {
                BasePlayer player = BasePlayer.FindByID(id);
                if (player == null || !player.IsConnected) continue;
                if (!permission.UserHasPermission(player.UserIDString, config.Permission))
                {
                    protectedPlayers.Remove(id);
                    continue;
                }
                TopUp(player);
            }
        }

        private void TopUp(BasePlayer player)
        {
            if (player == null || player.metabolism == null) return;

            if (player.health < player.MaxHealth())
                player.health = player.MaxHealth();

            player.metabolism.calories.value = player.metabolism.calories.max;
            player.metabolism.hydration.value = player.metabolism.hydration.max;
            player.metabolism.SendChanges();
        }
    }
}