OnLiquidWeaponFiringStopped

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

namespace Oxide.Plugins
{
    [Info("LiquidWeaponCooldown", "RustPluginGenerator", "1.0.0")]
    [Description("Enforces a per-player cooldown after a flamethrower stops firing")]
    public class LiquidWeaponCooldown : RustPlugin
    {
        private const string PermShortCooldown = "liquidweaponcooldown.vip";

        private PluginConfig config;
        private readonly Dictionary<string, float> lastStop = new Dictionary<string, float>();
        private Timer cleanupTimer;

        private class PluginConfig
        {
            [JsonProperty("Default cooldown in seconds")]
            public float DefaultCooldown = 3f;

            [JsonProperty("VIP cooldown in seconds")]
            public float VipCooldown = 1f;
        }

        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>
            {
                ["Cooldown"] = "Flamethrower cooling down. Wait {0}s.",
                ["Ready"] = "Flamethrower ready."
            }, 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(PermShortCooldown, this);
            cleanupTimer = timer.Every(120f, Cleanup);
        }

        private void Unload()
        {
            cleanupTimer?.Destroy();
            lastStop.Clear();
        }

        private void OnLiquidWeaponFiringStopped(LiquidWeapon liquidWeapon)
        {
            if (liquidWeapon == null) return;

            BasePlayer player = liquidWeapon.GetOwnerPlayer();
            if (player == null || player.IsNpc) return;

            float cooldown = GetCooldown(player);
            lastStop[player.UserIDString] = Time.realtimeSinceStartup;

            if (player.IsConnected)
            {
                player.ChatMessage(Msg("Cooldown", player.UserIDString, cooldown.ToString("0.#")));
            }
        }

        private object CanFireLiquidWeapon(LiquidWeapon liquidWeapon, BasePlayer player)
        {
            if (liquidWeapon == null || player == null) return null;

            float stoppedAt;
            if (!lastStop.TryGetValue(player.UserIDString, out stoppedAt)) return null;

            float cooldown = GetCooldown(player);
            float elapsed = Time.realtimeSinceStartup - stoppedAt;
            if (elapsed >= cooldown) return null;

            player.ChatMessage(Msg("Cooldown", player.UserIDString, (cooldown - elapsed).ToString("0.#")));
            return false;
        }

        private float GetCooldown(BasePlayer player)
        {
            return permission.UserHasPermission(player.UserIDString, PermShortCooldown)
                ? Mathf.Max(0f, config.VipCooldown)
                : Mathf.Max(0f, config.DefaultCooldown);
        }

        private void Cleanup()
        {
            float now = Time.realtimeSinceStartup;
            List<string> stale = null;
            foreach (KeyValuePair<string, float> entry in lastStop)
            {
                if (now - entry.Value > 300f)
                {
                    if (stale == null) stale = new List<string>();
                    stale.Add(entry.Key);
                }
            }
            if (stale == null) return;
            foreach (string id in stale) lastStop.Remove(id);
        }
    }
}