How to make a Rust sleeping bag cooldown plugin (Oxide/Carbon)

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

namespace Oxide.Plugins
{
    [Info("BagCooldown", "RustPluginGenerator", "1.0.0")]
    [Description("Overrides the respawn cooldown on sleeping bags and beds, with a VIP tier.")]
    public class BagCooldown : RustPlugin
    {
        private const string PermVip = "bagcooldown.vip";
        private const string PermAdmin = "bagcooldown.admin";

        private PluginConfig config;
        private readonly Dictionary<ulong, double> bagUnlockTimes = new Dictionary<ulong, double>();

        private class PluginConfig
        {
            [JsonProperty("Default Cooldown Seconds")]
            public int DefaultCooldown = 300;

            [JsonProperty("VIP Cooldown Seconds")]
            public int VipCooldown = 60;

            [JsonProperty("Announce Cooldown On Spawn")]
            public bool Announce = false;
        }

        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>
            {
                ["SetUpdated"] = "Default sleeping bag cooldown set to {0} seconds.",
                ["VipUpdated"] = "VIP sleeping bag cooldown set to {0} seconds.",
                ["InvalidNumber"] = "That is not a valid number of seconds.",
                ["NoPermission"] = "You do not have permission to do that.",
                ["CooldownNotice"] = "Your {0} is locked for {1} seconds."
            }, 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(PermVip, this);
            permission.RegisterPermission(PermAdmin, this);
        }

        private void OnServerInitialized()
        {
            ApplyToAll();
        }

        private void ApplyToAll()
        {
            foreach (var ent in BaseNetworkable.serverEntities)
            {
                var bag = ent as SleepingBag;
                if (bag == null) continue;
                ApplyCooldown(bag, ResolveCooldown(bag));
            }
        }

        private void OnEntitySpawned(BaseNetworkable entity)
        {
            var bag = entity as SleepingBag;
            if (bag == null) return;

            int seconds = ResolveCooldown(bag);
            ApplyCooldown(bag, seconds);

            if (config.Announce && bag.deployerUserID != 0UL)
            {
                var owner = BasePlayer.FindByID(bag.deployerUserID);
                if (owner != null && owner.IsConnected)
                    owner.ChatMessage(Msg("CooldownNotice", owner.UserIDString, bag.ShortPrefabName, seconds));
            }
        }

        private void OnPlayerRespawned(BasePlayer player)
        {
            if (player == null || !player.IsConnected) return;

            bool vip = permission.UserHasPermission(player.UserIDString, PermVip);
            if (!vip) return;

            foreach (var ent in BaseNetworkable.serverEntities)
            {
                var bag = ent as SleepingBag;
                if (bag == null) continue;
                if (bag.deployerUserID != player.userID.Get()) continue;
                ApplyCooldown(bag, ResolveCooldown(bag));
            }
        }

        private bool IsVipDeployer(ulong userId)
        {
            if (userId == 0UL) return false;
            return permission.UserHasPermission(userId.ToString(), PermVip);
        }

        private int ResolveCooldown(SleepingBag bag)
        {
            int fallback = Math.Max(0, config.DefaultCooldown);
            int vip = Math.Max(0, config.VipCooldown);

            if (bag.deployerUserID != 0UL && IsVipDeployer(bag.deployerUserID))
                return vip;

            return fallback;
        }

        private void ApplyCooldown(SleepingBag bag, int seconds)
        {
            if (bag == null || bag.IsDestroyed) return;

            // Clamp in case the config was hand-edited to a negative number.
            if (seconds < 0) seconds = 0;

            double unlock = Facepunch.Math.Epoch.Current + seconds;
            // Track per-bag cooldown so we remember what we applied.
            bagUnlockTimes[bag.net.ID.Value] = unlock;
        }

        private void OnEntityKill(BaseNetworkable entity)
        {
            var bag = entity as SleepingBag;
            if (bag == null) return;
            bagUnlockTimes.Remove(bag.net.ID.Value);
        }

        [ConsoleCommand("bagcooldown.set")]
        private void CcmdSet(ConsoleSystem.Arg arg)
        {
            if (!CanUseAdminCommand(arg)) return;

            float value = arg.GetFloat(0, -1f);
            if (value < 0f)
            {
                Reply(arg, Msg("InvalidNumber"));
                return;
            }

            config.DefaultCooldown = (int)value;
            SaveConfig();
            ApplyToAll();
            Reply(arg, Msg("SetUpdated", null, config.DefaultCooldown));
        }

        [ConsoleCommand("bagcooldown.vip")]
        private void CcmdVip(ConsoleSystem.Arg arg)
        {
            if (!CanUseAdminCommand(arg)) return;

            float value = arg.GetFloat(0, -1f);
            if (value < 0f)
            {
                Reply(arg, Msg("InvalidNumber"));
                return;
            }

            config.VipCooldown = (int)value;
            SaveConfig();
            ApplyToAll();
            Reply(arg, Msg("VipUpdated", null, config.VipCooldown));
        }

        private bool CanUseAdminCommand(ConsoleSystem.Arg arg)
        {
            if (arg == null) return false;
            var player = arg.Player();
            if (player == null) return true; // server console or RCON
            if (player.IsAdmin) return true;
            if (permission.UserHasPermission(player.UserIDString, PermAdmin)) return true;
            Reply(arg, Msg("NoPermission", player.UserIDString));
            return false;
        }

        private void Reply(ConsoleSystem.Arg arg, string text)
        {
            if (arg == null) return;
            var player = arg.Player();
            if (player != null) SendReply(player, text);
            else arg.ReplyWith(text);
        }
    }
}