How to make a Rust team death alerts plugin (killer and grid)

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

namespace Oxide.Plugins
{
    [Info("Team Death Alerts", "RustPluginGenerator", "1.0.0")]
    [Description("Sends online teammates a chat alert with the killer name and map grid when a player dies.")]
    public class TeamDeathAlerts : RustPlugin
    {
        private const string PermUse = "teamdeathalerts.use";
        private const string PermAdmin = "teamdeathalerts.admin";

        private PluginConfig config;
        private readonly Dictionary<ulong, float> lastAlert = new Dictionary<ulong, float>();

        private class PluginConfig
        {
            [JsonProperty("Alert format (body text)")]
            public string AlertFormat { get; set; } = "<color=#ff6b6b>{victim}</color> was killed by <color=#ffd166>{killer}</color> at grid <color=#8ecae6>{grid}</color> ({damage}).";

            [JsonProperty("Show grid in alerts")]
            public bool ShowGrid { get; set; } = true;

            [JsonProperty("Grid cell size (metres)")]
            public float GridSize { get; set; } = 146f;

            [JsonProperty("Ignore suicide deaths")]
            public bool IgnoreSuicide { get; set; } = true;

            [JsonProperty("Ignore deaths with no attacker")]
            public bool IgnoreEnvironment { get; set; } = false;

            [JsonProperty("Alert cooldown per team (seconds)")]
            public float AlertCooldown { get; set; } = 3f;
        }

        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>
            {
                ["Alert"] = "{0}",
                ["UnknownKiller"] = "an unknown source",
                ["DamageFormat"] = "{0} damage",
                ["TestPrefix"] = "[TeamDeathAlerts] Sample alert:",
                ["StatusHeader"] = "TeamDeathAlerts status:",
                ["NoPermission"] = "You do not have permission to use this command."
            }, this);
        }

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

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

        private object OnPlayerDeath(BasePlayer player, HitInfo info)
        {
            if (player == null || player.IsNpc) return null;
            if (player.currentTeam == 0) return null;

            var damageType = info?.damageTypes != null
                ? info.damageTypes.GetMajorityDamageType()
                : Rust.DamageType.Generic;

            if (config.IgnoreSuicide && damageType == Rust.DamageType.Suicide) return null;

            BaseEntity attacker = info?.Initiator;
            if (config.IgnoreEnvironment && attacker == null) return null;

            var team = RelationshipManager.ServerInstance.FindTeam(player.currentTeam);
            if (team == null || team.members == null || team.members.Count < 2) return null;

            float now = Time.realtimeSinceStartup;
            float last;
            if (config.AlertCooldown > 0f && lastAlert.TryGetValue(player.currentTeam, out last) && now - last < config.AlertCooldown)
                return null;
            lastAlert[player.currentTeam] = now;

            string killer = ResolveKillerName(attacker);
            string grid = config.ShowGrid ? GetGrid(player.transform.position) : "";
            string damage = Msg("DamageFormat", null, PrettyDamage(damageType));

            string body = config.AlertFormat
                .Replace("{victim}", player.displayName)
                .Replace("{killer}", killer)
                .Replace("{grid}", grid)
                .Replace("{damage}", damage);

            foreach (ulong memberId in team.members)
            {
                if (memberId == player.userID.Get()) continue;
                BasePlayer member = BasePlayer.FindByID(memberId);
                if (member == null || !member.IsConnected || member.IsSleeping()) continue;
                member.ChatMessage(Msg("Alert", member.UserIDString, body));
            }

            return null;
        }

        private string ResolveKillerName(BaseEntity attacker)
        {
            if (attacker == null) return Msg("UnknownKiller");

            var attackerPlayer = attacker as BasePlayer;
            if (attackerPlayer != null)
                return attackerPlayer.displayName;

            var scientist = attacker as ScientistNPC;
            if (scientist != null)
            {
                if (scientist.ShortPrefabName != null && scientist.ShortPrefabName.Contains("scarecrow"))
                    return "Scarecrow";
                return "Scientist";
            }

            if (attacker is BaseAnimalNPC) return "Animal";
            if (attacker is PatrolHelicopter) return "Patrol Helicopter";
            if (attacker is BradleyAPC) return "Bradley APC";

            return attacker.ShortPrefabName ?? Msg("UnknownKiller");
        }

        private string PrettyDamage(Rust.DamageType type)
        {
            switch (type)
            {
                case Rust.DamageType.Bullet: return "bullet";
                case Rust.DamageType.Explosion: return "explosion";
                case Rust.DamageType.Slash: return "melee";
                case Rust.DamageType.Stab: return "melee";
                case Rust.DamageType.Blunt: return "melee";
                case Rust.DamageType.Heat: return "fire";
                case Rust.DamageType.Fall: return "fall";
                case Rust.DamageType.Suicide: return "suicide";
                case Rust.DamageType.Decay: return "decay";
                case Rust.DamageType.Bite: return "animal";
                default: return type.ToString().ToLowerInvariant();
            }
        }

        private string GetGrid(Vector3 pos)
        {
            float cell = config.GridSize <= 0f ? 146f : config.GridSize;
            int column = Mathf.FloorToInt((pos.x + World.Size / 2f) / cell);
            int row = Mathf.FloorToInt((pos.z + World.Size / 2f) / cell);
            char letter = (char)('A' + Mathf.Clamp(column, 0, 25));
            return string.Concat(letter, row.ToString());
        }

        [ChatCommand("tda")]
        private void CmdTda(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 == 0 || args[0].ToLowerInvariant() != "test")
            {
                player.ChatMessage("/tda test");
                return;
            }

            string body = config.AlertFormat
                .Replace("{victim}", player.displayName)
                .Replace("{killer}", "Example Killer")
                .Replace("{grid}", config.ShowGrid ? GetGrid(player.transform.position) : "")
                .Replace("{damage}", Msg("DamageFormat", null, "bullet"));

            player.ChatMessage(Msg("TestPrefix", player.UserIDString));
            player.ChatMessage(Msg("Alert", player.UserIDString, body));
        }

        [ConsoleCommand("teamdeathalerts.status")]
        private void CcmdStatus(ConsoleSystem.Arg arg)
        {
            var player = arg.Player();
            if (player != null && !permission.UserHasPermission(player.UserIDString, PermAdmin))
            {
                player.ChatMessage(Msg("NoPermission", player.UserIDString));
                return;
            }

            string text = Msg("StatusHeader") +
                          "\nAlert format: " + config.AlertFormat +
                          "\nShow grid: " + config.ShowGrid +
                          "\nGrid size: " + config.GridSize +
                          "\nIgnore suicide: " + config.IgnoreSuicide +
                          "\nIgnore environment: " + config.IgnoreEnvironment +
                          "\nCooldown: " + config.AlertCooldown;

            if (player != null) player.ChatMessage(text);
            else arg.ReplyWith(text);
        }
    }
}