using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Oxide.Core;
using Oxide.Core.Plugins;
using Newtonsoft.Json;

//  ____  _       _ _       
// / ___|(_) __ _(_) | ___  
// \___ \| |/ _` | | |/ _ \ 
//  ___) | | (_| | | | (_) |
// |____/|_|\__, |_|_|\___/ 
//          |___/             
// ☽✧✵✧✵✧✵✧✵✧✵✧✵✧☾
// ✦    RUST PLUGINS   ✦
// ✦     Sigilo.dev    ✦
// ☽✧✵✧✵✧✵✧✵✧✵✧✵✧☾

namespace Oxide.Plugins
{
    [Info("KDR", "Sigilo", "1.0.1")]
    [Description("Shows kills, deaths, KDR and a top 10 leaderboard")]
    class KDR : RustPlugin
    {
        private const string PERMISSION_NAME = "kdr.use";
        private ConcurrentDictionary<string, (int Kills, int Deaths)> playerStats = new ConcurrentDictionary<string, (int, int)>();
        private ConcurrentDictionary<string, PlayerKDR> playerKDR = new ConcurrentDictionary<string, PlayerKDR>();

        class PlayerKDR
        {
            public string UserID { get; set; }
            public string Name { get; set; }
            public float KDR { get; set; }
        }

        void Init()
        {
            permission.RegisterPermission(PERMISSION_NAME, this);
            cmd.AddChatCommand("kdr", this, "CmdKDR");
            cmd.AddChatCommand("kdrtop", this, "CmdKDRTop");
        }

        void Loaded()
        {
            var data = Interface.Oxide.DataFileSystem.ReadObject<Dictionary<string, (int, int)>>("KDRData");
            foreach (var entry in data)
            {
                playerStats[entry.Key] = entry.Value;
            }
            try
            {
                playerKDR = new ConcurrentDictionary<string, PlayerKDR>(Interface.Oxide.DataFileSystem.ReadObject<Dictionary<string, PlayerKDR>>("KDR").ToDictionary(entry => entry.Key, entry => entry.Value));
            }
            catch (JsonReaderException)
            {
                Puts("Error reading KDR data. The data might be in an incorrect format.");
                playerKDR = new ConcurrentDictionary<string, PlayerKDR>();
            }
        }

        void Unload()
        {
            Interface.Oxide.DataFileSystem.WriteObject("KDRData", playerStats.ToDictionary(entry => entry.Key, entry => entry.Value));
            Interface.Oxide.DataFileSystem.WriteObject("KDR", playerKDR.ToDictionary(entry => entry.Key, entry => entry.Value));
        }

        void OnPlayerDeath(BasePlayer player, HitInfo info)
        {
            if (info?.InitiatorPlayer != null && player != null && player.userID != 0)
            {
                if (info.InitiatorPlayer.userID != player.userID)
                {
                    OnPlayerKill(info.InitiatorPlayer, player);
                }
            }
        }

        void OnPlayerKill(BasePlayer killer, BasePlayer victim)
        {
            string killerId = killer.UserIDString;
            string victimId = victim.UserIDString;

            if (!IsValidSteamID(victim.userID))
            {
                return;
            }

            playerStats.AddOrUpdate(killerId, (1, 0), (key, oldValue) => (oldValue.Kills + 1, oldValue.Deaths));
            playerStats.AddOrUpdate(victimId, (0, 1), (key, oldValue) => (oldValue.Kills, oldValue.Deaths + 1));

            Task.Run(() => UpdateKDR(killerId, victimId));
        }

        async Task UpdateKDR(string killerId, string victimId)
        {
            float killerKDR = CalculateKDR(killerId);
            float victimKDR = CalculateKDR(victimId);

            playerKDR[killerId] = new PlayerKDR { UserID = killerId, Name = covalence.Players.FindPlayerById(killerId)?.Name ?? "Unknown", KDR = killerKDR };
            playerKDR[victimId] = new PlayerKDR { UserID = victimId, Name = covalence.Players.FindPlayerById(victimId)?.Name ?? "Unknown", KDR = victimKDR };
        }

        float CalculateKDR(string playerId)
        {
            var stats = playerStats.GetOrAdd(playerId, (0, 0));
            return stats.Deaths != 0 ? (float)stats.Kills / stats.Deaths : stats.Kills;
        }

        [ChatCommand("kdr")]
        void CmdKDR(BasePlayer player, string command, string[] args)
        {
            string playerId = player.UserIDString;

            if (!permission.UserHasPermission(playerId, PERMISSION_NAME))
            {
                SendReply(player, "You do not have permission to use this command.");
                return;
            }

            var stats = playerStats.GetOrAdd(playerId, (0, 0));
            float kdr = playerKDR.ContainsKey(playerId) ? playerKDR[playerId].KDR : CalculateKDR(playerId);

            SendReply(player, $"Your kills: <color=#ff686b>{stats.Kills}</color>, deaths: <color=#ff686b>{stats.Deaths}</color>, KDR: <color=#ff686b>{kdr.ToString("0.0")}</color>.");
        }

        [ChatCommand("kdrtop")]
        void CmdKDRTop(BasePlayer player, string command, string[] args)
        {
            string playerId = player.UserIDString;

            if (!permission.UserHasPermission(playerId, PERMISSION_NAME))
            {
                SendReply(player, "You do not have permission to use this command.");
                return;
            }

            var topKDRs = playerKDR.Values.OrderByDescending(x => x.KDR).Take(10);
            string message = "<color=#ff686b>Top KDRs:</color>\n";
            foreach (var kdr in topKDRs)
            {
                string kdrString = kdr.KDR.ToString("0.0").PadRight(5);
                message += $"<color=#ff686b>{kdrString}</color>| {kdr.Name}\n";
            }

            SendReply(player, message);
        }

        void SendReply(BasePlayer player, string message)
        {
            player.ChatMessage(message);
        }

        bool IsValidSteamID(ulong userID)
        {
            string userIDString = userID.ToString();
            return userIDString.StartsWith("7656") && userIDString.Length == 17;
        }
    }
}