OnItemLock

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

namespace Oxide.Plugins
{
    [Info("Pinned Item Lock Guard", "RustPluginGenerator", "1.0.0")]
    [Description("Prevents configured item shortnames from ever entering the locked state.")]
    public class PinnedItemLockGuard : RustPlugin
    {
        private const string PermNotify = "pinneditemlockguard.notify";

        private PluginConfig config;
        private readonly Dictionary<ulong, float> lastNotice = new Dictionary<ulong, float>();

        private class PluginConfig
        {
            [JsonProperty("Pinned shortnames (lock attempts are cancelled)")]
            public List<string> PinnedShortnames = new List<string> { "scrap", "supply.signal" };

            [JsonProperty("Notify the item owner when a lock is blocked")]
            public bool NotifyOwner = true;
        }

        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>
            {
                ["LockBlocked"] = "This item is pinned and cannot be locked."
            }, this);
        }

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

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

        private object OnItemLock(Item item)
        {
            if (item == null || item.info == null || config.PinnedShortnames == null) return null;
            if (!config.PinnedShortnames.Contains(item.info.shortname)) return null;

            if (!config.NotifyOwner) return true;

            var player = item.GetOwnerPlayer();
            if (player == null || !player.IsConnected) return true;
            if (!permission.UserHasPermission(player.UserIDString, PermNotify)) return true;

            ulong id = player.userID;
            float now = UnityEngine.Time.realtimeSinceStartup;
            float last;
            if (lastNotice.TryGetValue(id, out last) && now - last < 10f) return true;

            lastNotice[id] = now;
            player.ChatMessage(Msg("LockBlocked", player.UserIDString));
            return true;
        }
    }
}