OnDeepSeaOpen

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

namespace Oxide.Plugins
{
    [Info("Deep Sea Open Announcer", "RustPluginGenerator", "1.0.0")]
    [Description("Announces deep sea openings in chat and keeps a small history for admins")]
    public class DeepSeaOpenAnnouncer : RustPlugin
    {
        private const string PermAdmin = "deepseaopenannouncer.admin";

        private PluginConfig config;
        private readonly List<string> openings = new List<string>();

        private class PluginConfig
        {
            [JsonProperty("Announce in chat")]
            public bool AnnounceInChat { get; set; } = true;

            [JsonProperty("Keep history entries")]
            public int HistoryLimit { get; set; } = 10;
        }

        private class AnnounceState
        {
            [JsonProperty("Last openings (UTC)")]
            public List<string> Openings { get; set; } = new List<string>();
        }

        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>
            {
                ["Announce"] = "The deep sea is opening. Head to the docks and sail out.",
                ["LastOpening"] = "Last deep sea opening: {0}",
                ["NoHistory"] = "No deep sea opening recorded yet."
            }, this);
        }

        private string Msg(string key, string userId = null, params object[] args)
        {
            return string.Format(lang.GetMessage(key, this, userId), args);
        }

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

        private void LoadHistory()
        {
            var state = Interface.Oxide.DataFileSystem.ReadObject<AnnounceState>(Name);
            if (state?.Openings != null)
            {
                openings.Clear();
                openings.AddRange(state.Openings);
            }
        }

        private void SaveHistory()
        {
            Interface.Oxide.DataFileSystem.WriteObject(Name, new AnnounceState { Openings = new List<string>(openings) });
        }

        private void OnDeepSeaOpen(DeepSeaManager deepSeaManager)
        {
            if (deepSeaManager == null || deepSeaManager.IsDestroyed) return;

            string stamp = DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss") + " UTC";
            openings.Add(stamp);
            while (openings.Count > Math.Max(1, config.HistoryLimit))
                openings.RemoveAt(0);
            SaveHistory();

            if (config.AnnounceInChat)
                Server.Broadcast(Msg("Announce"));
        }

        [ConsoleCommand("deepsea.last")]
        private void CmdLast(ConsoleSystem.Arg arg)
        {
            var player = arg.Player();
            if (player != null && !player.IsAdmin && !permission.UserHasPermission(player.UserIDString, PermAdmin)) return;

            string reply = openings.Count == 0
                ? Msg("NoHistory")
                : Msg("LastOpening", player?.UserIDString, openings[openings.Count - 1]);

            if (player != null) SendReply(player, reply);
            else if (arg != null) arg.ReplyWith(reply);
        }
    }
}