OnNewSave

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

namespace Oxide.Plugins
{
    [Info("New Save Notifier", "RustPluginGenerator", "1.0.0")]
    [Description("Records when a server starts on a brand new save and notifies staff")]
    public class NewSaveNotifier : RustPlugin
    {
        private const string PermNotify = "newsavenotifier.notify";
        private const string DataFile = "NewSaveNotifier";

        private PluginConfig config;
        private StoredData data;

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

        private class StoredData
        {
            [JsonProperty("Last new save filename")]
            public string LastFilename { get; set; } = string.Empty;

            [JsonProperty("Last new save time (UTC)")]
            public string LastTimeUtc { get; set; } = string.Empty;

            [JsonProperty("Announcement sent")]
            public bool AnnouncementSent { get; set; }
        }

        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>
            {
                ["NewSaveDetected"] = "New save detected: {0}",
                ["AdminSummary"] = "This server started on a new save ({0}). Staff have been notified."
            }, 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(PermNotify, this);
        }

        private void OnServerInitialized()
        {
            data = Interface.Oxide.DataFileSystem.ReadObject<StoredData>(DataFile) ?? new StoredData();

            if (string.IsNullOrEmpty(data.LastFilename))
            {
                return;
            }

            PrintWarning(Msg("NewSaveDetected", null, data.LastFilename));

            if (!config.AnnounceToAdmins || data.AnnouncementSent)
            {
                return;
            }

            foreach (BasePlayer player in BasePlayer.activePlayerList)
            {
                if (player == null || !player.IsConnected) continue;
                if (!player.IsAdmin && !permission.UserHasPermission(player.UserIDString, PermNotify)) continue;

                player.ChatMessage(Msg("AdminSummary", player.UserIDString, data.LastFilename));
            }
        }

        private void OnNewSave(string filename)
        {
            data = new StoredData
            {
                LastFilename = filename ?? string.Empty,
                LastTimeUtc = DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss"),
                AnnouncementSent = false
            };

            Interface.Oxide.DataFileSystem.WriteObject(DataFile, data);
            PrintWarning("Fresh world detected, save file was missing: " + data.LastFilename);
        }

        private void Unload()
        {
            if (data != null)
            {
                Interface.Oxide.DataFileSystem.WriteObject(DataFile, data);
            }
        }
    }
}