OnMlrsFiringEnded

using System;
using System.Collections.Generic;
using Newtonsoft.Json;

namespace Oxide.Plugins
{
    [Info("Mlrs Salvo Cooldown", "RustPluginGenerator", "1.0.0")]
    [Description("Tracks when a player's MLRS finishes a salvo and reports the next allowed launch time.")]
    public class MlrsSalvoCooldown : RustPlugin
    {
        private const string PermUse = "mlrssalvocooldown.use";

        private PluginConfig config;
        private readonly Dictionary<ulong, DateTime> lastSalvo = new Dictionary<ulong, DateTime>();

        private class PluginConfig
        {
            [JsonProperty("Salvo cooldown in seconds")]
            public int CooldownSeconds { get; set; } = 600;
        }

        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>
            {
                ["SalvoEnded"] = "Your MLRS salvo ended. Next salvo allowed in {0} seconds.",
                ["Ready"] = "Your MLRS is ready to fire.",
                ["OnCooldown"] = "Your MLRS is on cooldown for another {0} seconds.",
                ["NoPermission"] = "You do not have permission to use this command."
            }, 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 OnMlrsFiringEnded(MLRS mLRS)
        {
            if (mLRS == null) return;

            ulong ownerId = mLRS.OwnerID;
            if (ownerId == 0) return;

            lastSalvo[ownerId] = DateTime.UtcNow;

            var player = BasePlayer.FindAwakeOrSleeping(ownerId.ToString());
            if (player != null && player.IsConnected)
            {
                player.ChatMessage(Msg("SalvoEnded", player.UserIDString, config.CooldownSeconds));
            }
        }

        [ChatCommand("canfire")]
        private void CmdCanFire(BasePlayer player, string command, string[] args)
        {
            if (player == null) return;
            if (!permission.UserHasPermission(player.UserIDString, PermUse))
            {
                player.ChatMessage(Msg("NoPermission", player.UserIDString));
                return;
            }

            int remaining = GetRemainingSeconds(player.userID.Get());
            if (remaining <= 0)
            {
                player.ChatMessage(Msg("Ready", player.UserIDString));
                return;
            }

            player.ChatMessage(Msg("OnCooldown", player.UserIDString, remaining));
        }

        private int GetRemainingSeconds(ulong ownerId)
        {
            DateTime last;
            if (!lastSalvo.TryGetValue(ownerId, out last)) return 0;

            double elapsed = (DateTime.UtcNow - last).TotalSeconds;
            double left = config.CooldownSeconds - elapsed;
            return left > 0 ? (int)Math.Ceiling(left) : 0;
        }

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