How to make a Rust player report plugin (Oxide/Carbon /report command)

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

namespace Oxide.Plugins
{
    [Info("Report Command", "RustPluginGenerator", "1.0.0")]
    [Description("Adds /report and /reports commands with admin notifications, storage and cooldown.")]
    public class ReportCommand : RustPlugin
    {
        private const string PermUse = "reportcommand.use";
        private const string PermAdmin = "reportcommand.admin";
        private const string PermNotify = "reportcommand.notify";
        private const string DataFile = "ReportCommand";

        private PluginConfig config;
        private List<ReportEntry> reports = new List<ReportEntry>();
        private readonly Dictionary<ulong, float> lastReport = new Dictionary<ulong, float>();

        private class PluginConfig
        {
            [JsonProperty("Cooldown seconds")]
            public int CooldownSeconds { get; set; } = 120;

            [JsonProperty("Max stored reports")]
            public int MaxStoredReports { get; set; } = 500;

            [JsonProperty("Reports shown per page")]
            public int ReportsShownPerPage { get; set; } = 10;
        }

        private class ReportEntry
        {
            public string ReporterName { get; set; }
            public string ReporterId { get; set; }
            public string TargetName { get; set; }
            public string TargetId { get; set; }
            public string Reason { get; set; }
            public long CreatedUtc { 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>
            {
                ["Usage"] = "Usage: /report <player> <reason>",
                ["NotFound"] = "Player '{0}' was not found.",
                ["SelfReport"] = "You cannot report yourself.",
                ["Cooldown"] = "You must wait {0} more second(s) before reporting again.",
                ["Received"] = "Your report against {0} has been submitted.",
                ["Notify"] = "Report: {0} ({1}) reported {2} ({3}) for: {4}",
                ["NoReports"] = "There are no stored reports.",
                ["ReportsHeader"] = "Last {0} report(s):",
                ["ReportLine"] = "{0} | {1} -> {2}: {3}",
                ["NoPermission"] = "You don't 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);
            permission.RegisterPermission(PermAdmin, this);
            permission.RegisterPermission(PermNotify, this);
        }

        private void OnServerInitialized()
        {
            reports = Interface.Oxide.DataFileSystem.ReadObject<List<ReportEntry>>(DataFile) ?? new List<ReportEntry>();
        }

        private void Unload()
        {
            SaveData();
        }

        private void SaveData()
        {
            Interface.Oxide.DataFileSystem.WriteObject(DataFile, reports);
        }

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

            if (args == null || args.Length < 2)
            {
                player.ChatMessage(Msg("Usage", player.UserIDString));
                return;
            }

            BasePlayer target = BasePlayer.FindAwakeOrSleeping(args[0]);
            if (target == null && ulong.TryParse(args[0], out ulong targetId))
            {
                target = BasePlayer.FindByID(targetId);
            }
            if (target == null)
            {
                player.ChatMessage(Msg("NotFound", player.UserIDString, args[0]));
                return;
            }
            if (target.userID == player.userID)
            {
                player.ChatMessage(Msg("SelfReport", player.UserIDString));
                return;
            }

            bool isNotifier = permission.UserHasPermission(player.UserIDString, PermNotify);
            if (!isNotifier && config.CooldownSeconds > 0)
            {
                float now = Time.realtimeSinceStartup;
                if (lastReport.TryGetValue(player.userID, out float prev))
                {
                    float remaining = config.CooldownSeconds - (now - prev);
                    if (remaining > 0f)
                    {
                        player.ChatMessage(Msg("Cooldown", player.UserIDString, Mathf.CeilToInt(remaining)));
                        return;
                    }
                }
            }

            string reason = string.Join(" ", args, 1, args.Length - 1).Trim();
            if (string.IsNullOrEmpty(reason))
            {
                player.ChatMessage(Msg("Usage", player.UserIDString));
                return;
            }

            var entry = new ReportEntry
            {
                ReporterName = player.displayName,
                ReporterId = player.UserIDString,
                TargetName = target.displayName,
                TargetId = target.UserIDString,
                Reason = reason,
                CreatedUtc = DateTimeOffset.UtcNow.ToUnixTimeSeconds()
            };
            reports.Add(entry);
            TrimReports();
            SaveData();
            lastReport[player.userID] = Time.realtimeSinceStartup;

            player.ChatMessage(Msg("Received", player.UserIDString, target.displayName));
            NotifyAdmins(entry);
        }

        [ChatCommand("reports")]
        private void CmdReports(BasePlayer player, string command, string[] args)
        {
            if (player == null) return;
            if (!permission.UserHasPermission(player.UserIDString, PermAdmin))
            {
                player.ChatMessage(Msg("NoPermission", player.UserIDString));
                return;
            }
            if (reports.Count == 0)
            {
                player.ChatMessage(Msg("NoReports", player.UserIDString));
                return;
            }

            int limit = Mathf.Max(1, config.ReportsShownPerPage);
            int shown = 0;
            player.ChatMessage(Msg("ReportsHeader", player.UserIDString, limit));
            for (int i = reports.Count - 1; i >= 0 && shown < limit; i--, shown++)
            {
                var r = reports[i];
                string time = DateTimeOffset.FromUnixTimeSeconds(r.CreatedUtc).ToLocalTime().ToString("HH:mm");
                player.ChatMessage(Msg("ReportLine", player.UserIDString, time, r.ReporterName, r.TargetName, r.Reason));
            }
        }

        private void NotifyAdmins(ReportEntry entry)
        {
            foreach (var admin in BasePlayer.activePlayerList)
            {
                if (admin == null || !admin.IsConnected) continue;
                if (!permission.UserHasPermission(admin.UserIDString, PermNotify)) continue;
                admin.ChatMessage(Msg("Notify", admin.UserIDString, entry.ReporterName, entry.ReporterId, entry.TargetName, entry.TargetId, entry.Reason));
            }
        }

        private void TrimReports()
        {
            int max = Mathf.Max(1, config.MaxStoredReports);
            if (reports.Count <= max) return;
            reports.RemoveRange(0, reports.Count - max);
        }
    }
}