OnStructureUpgraded

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

namespace Oxide.Plugins
{
    [Info("Upgrade Rewards", "RustPluginGenerator", "1.0.0")]
    [Description("Gives players a configurable item reward when they upgrade a building block.")]
    public class UpgradeRewards : RustPlugin
    {
        private const string PermUse = "upgraderewards.use";

        private class PluginConfig
        {
            [JsonProperty("Reward cooldown in seconds")]
            public float CooldownSeconds = 2f;

            [JsonProperty("Reward shortname")]
            public string RewardShortname = "scrap";

            [JsonProperty("Reward amount for Metal")]
            public int MetalAmount = 1;

            [JsonProperty("Reward amount for TopTier")]
            public int TopTierAmount = 2;
        }

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

        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>
            {
                ["Reward"] = "You received {0}x {1} for upgrading to {2}.",
                ["NoPermission"] = "You do not have permission to earn upgrade rewards."
            }, 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(PermUse, this);
        }

        private void Unload()
        {
            lastReward.Clear();
        }

        private void OnStructureUpgraded(BuildingBlock buildingBlock, BasePlayer player, BuildingGrade.Enum type, ulong skin)
        {
            if (player == null || !player.IsConnected) return;
            if (!permission.UserHasPermission(player.UserIDString, PermUse)) return;

            int amount = 0;
            if (type == BuildingGrade.Enum.Metal) amount = config.MetalAmount;
            else if (type == BuildingGrade.Enum.TopTier) amount = config.TopTierAmount;
            if (amount <= 0) return;

            float now = Time.realtimeSinceStartup;
            float last;
            if (lastReward.TryGetValue(player.userID, out last) && now - last < config.CooldownSeconds) return;
            lastReward[player.userID] = now;

            Item rewards = ItemManager.CreateByName(config.RewardShortname, amount);
            if (rewards == null)
            {
                PrintWarning($"Unknown reward shortname: {config.RewardShortname}");
                return;
            }

            if (!player.inventory.GiveItem(rewards))
            {
                rewards.Drop(player.transform.position + player.eyes.HeadForward() * 1.5f, Vector3.zero);
            }

            string rewardName = rewards.info != null ? rewards.info.displayName.english : config.RewardShortname;
            player.ChatMessage(Msg("Reward", player.UserIDString, amount, rewardName, type.ToString()));
        }
    }
}