OnStructureRepair

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

namespace Oxide.Plugins
{
    [Info("Repair Permission Gate", "RustPluginGenerator", "1.0.0")]
    [Description("Requires a permission before players can repair building blocks with a hammer")]
    public class RepairPermissionGate : RustPlugin
    {
        private const string PermUse = "repairpermissiongate.use";

        private PluginConfig config;

        private class PluginConfig
        {
            [JsonProperty("Require permission to repair")]
            public bool RequirePermission { get; set; } = 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>
            {
                ["NoPermission"] = "You do not have permission to repair structures.",
                ["Disabled"] = "Structure repair is currently disabled."
            }, this);
        }

        private string Msg(string key, string userId = null) => lang.GetMessage(key, this, userId);

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

        private object OnStructureRepair(BaseCombatEntity entity, BasePlayer player)
        {
            if (!config.RequirePermission) return null;
            if (entity == null || player == null) return null;
            if (entity is BuildingBlock == false) return null;
            if (player.IsAdmin) return null;
            if (permission.UserHasPermission(player.UserIDString, PermUse)) return null;

            player.ChatMessage(Msg("NoPermission", player.UserIDString));
            return true;
        }
    }
}