OnInventoryAmmoItemFind

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

namespace Oxide.Plugins
{
    [Info("Fuel Can Ammo Source", "RustPluginGenerator", "1.0.0")]
    [Description("Lets chainsaws and flamethrowers draw fuel from nearby configured storage containers.")]
    public class FuelCanAmmoSource : RustPlugin
    {
        private const string PermUse = "fuelcanammosource.use";

        private class PluginConfig
        {
            [JsonProperty("Search radius (metres)")]
            public float SearchRadius = 5f;

            [JsonProperty("Container short prefabs")]
            public List<string> ContainerPrefabs = new List<string>
            {
                "box.wooden.large",
                "woodbox_deployed",
                "fuelstorage"
            };
        }

        private PluginConfig config;

        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);

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

        private object OnInventoryAmmoItemFind(PlayerInventory inventory, ItemDefinition fuelType)
        {
            if (inventory == null || fuelType == null) return null;

            BasePlayer owner = inventory.containerMain != null ? inventory.containerMain.playerOwner : null;
            if (owner == null || !permission.UserHasPermission(owner.UserIDString, PermUse)) return null;

            List<BaseEntity> found = new List<BaseEntity>();
            Vis.Entities(owner.transform.position, config.SearchRadius, found);

            foreach (BaseEntity entity in found)
            {
                StorageContainer container = entity as StorageContainer;
                if (container == null || container.inventory == null) continue;
                if (!config.ContainerPrefabs.Contains(container.ShortPrefabName)) continue;

                foreach (Item item in container.inventory.itemList)
                {
                    if (item == null || item.info == null) continue;
                    if (item.info.itemid != fuelType.itemid) continue;
                    return item;
                }
            }

            return null;
        }
    }
}