OnBoomboxStationUpdate

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

namespace Oxide.Plugins
{
    [Info("Boombox Station Allowlist", "RustPluginGenerator", "1.0.0")]
    [Description("Restricts boombox radio stations to a configurable allowlist")]
    public class BoomboxStationAllowlist : RustPlugin
    {
        private const string PermBypass = "boomboxstationallowlist.bypass";

        private PluginConfig config;

        private class PluginConfig
        {
            [JsonProperty("Allowed stations")]
            public List<string> AllowedStations = new List<string> { "rustradio" };

            [JsonProperty("Show allowed stations in chat")]
            public bool ShowAllowed = true;
        }

        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>
            {
                ["StationBlocked"] = "That radio station is not allowed. Available: {0}",
                ["NoStations"] = "Radio stations are disabled on this server."
            }, 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(PermBypass, this);
        }

        private object OnBoomboxStationUpdate(BoomBox boomBox, string text, BasePlayer player)
        {
            if (config.AllowedStations == null || config.AllowedStations.Count == 0)
                return null;

            if (player != null && permission.UserHasPermission(player.UserIDString, PermBypass))
                return null;

            foreach (string allowed in config.AllowedStations)
            {
                if (string.Equals(allowed, text, StringComparison.OrdinalIgnoreCase))
                    return null;
            }

            if (player != null)
            {
                if (config.ShowAllowed)
                    player.ChatMessage(Msg("StationBlocked", player.UserIDString, string.Join(", ", config.AllowedStations)));
                else
                    player.ChatMessage(Msg("NoStations", player.UserIDString));
            }

            return true;
        }
    }
}