using System;
using System.Collections;
using System.Collections.Generic;
using TMPro;
using Unity.Netcode;
using UnityEngine;

public struct PlayerScore : INetworkSerializable, System.IEquatable<PlayerScore>
{

    public ulong ClientId;
    public int Score;

    public bool Equals(PlayerScore _other)
    {
        return ClientId == _other.ClientId && Score == _other.Score;
    }

    public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
    {
        serializer.SerializeValue(ref ClientId);
        serializer.SerializeValue(ref Score);
    }
}

public class RoundManager : NetworkBehaviour
{
    public static RoundManager Current { get; private set; }

    [SerializeField] private float roundStartDelay = 3f;
    [SerializeField] private Transform[] spawnPoints;

    private NetworkVariable<float> roundDuration = new NetworkVariable<float>(180f);
    private NetworkVariable<float> roundTimeRemaining = new NetworkVariable<float>(0f);

    private NetworkVariable<int> currentRound = new NetworkVariable<int>(0);
    private NetworkVariable<bool> isRoundActive = new NetworkVariable<bool>(false);

    private List<PlayerHealth> alivePlayers = new List<PlayerHealth>();

    private NetworkList<PlayerScore> playerScores = new NetworkList<PlayerScore>();

    // pitDefenders[i] = ClientId игрока, которому принадлежит яма с pitIndex == i
    private ulong[] pitDefenders;

    private const ulong NoWinner = ulong.MaxValue;

    public event Action<float> TimerChanged;
    public event Action<int> RoundChanged;
    public event Action ScoresChanged;

    public override void OnNetworkSpawn()
    {
        currentRound.OnValueChanged += OnRoundChanged;
        isRoundActive.OnValueChanged += OnRoundStateChanged;
        roundTimeRemaining.OnValueChanged += OnRoundTimeChanged;
        playerScores.OnListChanged += OnScoresChanged;


        if (IsServer)
        {
            currentRound.Value = 0;
            StartCoroutine(StartRoundWithDelay());
        }
    }

    private void Update()
    {
        if (!IsServer) return;
        if (!IsRoundActive) return;

        roundTimeRemaining.Value = Mathf.Max(0f, roundTimeRemaining.Value - Time.deltaTime);

        if (roundTimeRemaining.Value <= 0f)
        {
            StartCoroutine(EndRound(NoWinner));
        }

    }

    void Awake()
    {
        Current = this;
    }

    public void OnPlayerEnteredPit(int _pitIndex, ulong _enteringClientId)
    {
        if (!IsServer) return;
        if (!isRoundActive.Value) return;

        if (pitDefenders == null) return;
        if (_pitIndex < 0 || _pitIndex >= pitDefenders.Length) return;

        // Своя яма — не считается, побеждают только за попадание в ЧУЖУЮ яму.
        // Для клона сюда приходит ClientId его ОРИГИНАЛА (см. PitZone) — правило работает так же.
        if (_enteringClientId == pitDefenders[_pitIndex]) return;

        AddScore(_enteringClientId);
        StartCoroutine(EndRound(_enteringClientId));
    }

    private void AddScore(ulong _clientId)
    {
        for (int _i = 0; _i < playerScores.Count; _i++)
        {
            if (playerScores[_i].ClientId != _clientId) continue;

            playerScores[_i] = new PlayerScore
            {
                ClientId = _clientId,
                Score = playerScores[_i].Score + 1
            };
            return;
        }
    }

    public void OnPlayerDied(PlayerHealth _playerHealth)
    {
        // if (!IsServer) return;

        // alivePlayers.Remove(_playerHealth);

        // if (alivePlayers.Count <= 1)
        // {
        //     StartCoroutine(EndRound());
        // }
    }

    public void RegisterPlayer(ulong _clientId)
    {
        if (!IsServer) return;

        foreach (var _s in playerScores)
            if (_s.ClientId == _clientId) return;

        playerScores.Add(new PlayerScore { ClientId = _clientId, Score = 0 });
    }

    private IEnumerator EndRound(ulong _winnerClientId)
    {
        isRoundActive.Value = false;

        // Сразу: стоп клонов + запись раунда в архив.
        // Обязательно ДО WaitForSeconds — иначе клоны бегают и стреляют на экране победы.
        if (GhostRoundManager.Current != null)
            GhostRoundManager.Current.ServerEndRound();

        string _winner = _winnerClientId == NoWinner
            ? "No winner (time up)"
            : $"Player {_winnerClientId} wins!";

        RoundEndedClientRPC(_winner);

        yield return new WaitForSeconds(roundStartDelay);

        currentRound.Value++;
        StartCoroutine(StartRoundWithDelay());

    }

    private void RespawnAllPlayers()
    {
        if (!IsServer) return;
        if (spawnPoints == null || spawnPoints.Length == 0) return;

        PlayerHealth[] _found = FindObjectsByType<PlayerHealth>(FindObjectsSortMode.None);

        // Только живые игроки: у клона тоже есть PlayerHealth,
        // но ему нельзя давать яму и спавн-поинт
        List<PlayerHealth> _players = new List<PlayerHealth>();
        foreach (PlayerHealth _p in _found)
        {
            if (_p.GetComponent<GhostPlayer>() != null) continue;
            _players.Add(_p);
        }

        // Детерминированный порядок раздачи ям: клон слепо повторяет прошлый раунд,
        // значит "чья яма где" должно совпадать из раунда в раунд.
        // FindObjectsByType порядок не гарантирует — сортируем по ClientId.
        _players.Sort((_a, _b) => _a.OwnerClientId.CompareTo(_b.OwnerClientId));

        alivePlayers.Clear();

        // Одна яма на игрока: игрок с индексом _q защищает яму pitIndex == _q
        pitDefenders = new ulong[_players.Count];

        for (int _q = 0; _q < _players.Count; _q++)
        {
            ulong _clientId = _players[_q].OwnerClientId;

            RegisterPlayer(_clientId);
            pitDefenders[_q] = _clientId;

            Vector3 _spawnPosition = spawnPoints[_q % spawnPoints.Length].position;
            _players[_q].Respawn(_spawnPosition);

            alivePlayers.Add(_players[_q]);
        }
    }

    private IEnumerator StartRoundWithDelay()
    {
        yield return new WaitForSeconds(1f);

        yield return new WaitUntil(() => CountRealPlayers() >= 2);

        RespawnAllPlayers();

        // Спавним клонов прошлых раундов и включаем запись у живых игроков
        if (GhostRoundManager.Current != null)
            GhostRoundManager.Current.ServerStartRound();

        roundTimeRemaining.Value = roundDuration.Value;
        isRoundActive.Value = true;

        RoundStartedClientRPC(currentRound.Value);
    }

    // Считаем только настоящих игроков — у клонов тоже есть PlayerHealth
    private int CountRealPlayers()
    {
        PlayerHealth[] _found = FindObjectsByType<PlayerHealth>(FindObjectsSortMode.None);
        int _count = 0;
        foreach (PlayerHealth _p in _found)
            if (_p.GetComponent<GhostPlayer>() == null) _count++;
        return _count;
    }

    [ClientRpc]
    private void RoundStartedClientRPC(int _round)
    {
        Debug.Log($"Round {_round} started");
    }

    [ClientRpc]
    private void RoundEndedClientRPC(string _winnerText)
    {
        Debug.Log($"Round ended: {_winnerText}");
    }

    public bool IsRoundActive => isRoundActive.Value;
    public int CurrentRound => currentRound.Value;
    public float RoundTimeRemaining => roundTimeRemaining.Value;

    public int GetScore(ulong _clientId)
    {
        foreach (PlayerScore _s in playerScores)
            if (_s.ClientId == _clientId) return _s.Score;
        return 0;
    }

    // Для 2 игроков: счёт первого игрока, чей ClientId не равен локальному
    public int GetEnemyScore(ulong _localClientId)
    {
        foreach (PlayerScore _s in playerScores)
            if (_s.ClientId != _localClientId) return _s.Score;
        return 0;
    }

    public override void OnNetworkDespawn()
    {
        if (IsServer && Current == this)
            Current = null;

        currentRound.OnValueChanged -= OnRoundChanged;
        isRoundActive.OnValueChanged -= OnRoundStateChanged;
        roundTimeRemaining.OnValueChanged -= OnRoundTimeChanged;
        playerScores.OnListChanged -= OnScoresChanged;
    }

    private void OnScoresChanged(NetworkListEvent<PlayerScore> _event)
    {
        ScoresChanged?.Invoke();
    }

    private void OnRoundTimeChanged(float _previousValue, float _newValue)
    {
        TimerChanged?.Invoke(_newValue);
    }

    private void OnRoundChanged(int _previousValue, int _newValue)
    {
        RoundChanged?.Invoke(_newValue);
    }

    private void OnRoundStateChanged(bool _previousValue, bool _newValue)
    {

    }
}