using System;
using System.Collections.Generic;
using System.Threading;
using Cysharp.Threading.Tasks;
using TMPro;
using UnityEngine;

public class GameManager : MonoBehaviour
{
    public static GameManager Instance { get; private set; }

    [Header("Containers")]
    public CardContainer deckContainer;

    public CardContainer handContainer;
    public CardContainer boardContainer;
    public CardContainer discardContainer;

    [Header("Prefabs & UI")]
    public CardView cardPrefab;
    public TMP_Text statusText;
    public TMP_Text scoreText;

    [Header("Rules")]
    public int maxHandSize = 4;

    private int _playerScore;
    private int _enemyScore;
    private bool _isBusy;
    private CancellationToken _destroyToken;

    private void Awake()
    {
        Instance = this;
        _destroyToken = this.GetCancellationTokenOnDestroy();
    }

    private void Start()
    {
        StartGameAsync().Forget();
    }

    private async UniTaskVoid StartGameAsync()
    {
        _isBusy = true;
        UpdateScoreUI();
        SetStatus("Подготовка колоды...");

        CreateAndShuffleDeck();
        await UniTask.Delay(400, cancellationToken: _destroyToken);

        SetStatus("Раздаём карты...");
        for (var i = 0; i < 3; i++)
        {
            await DrawTopCardToHandAsync();
        }

        SetStatus("Ваш ход: сыграйте карту на поле или сбросьте ненужную");
        _isBusy = false;
    }

    private void CreateAndShuffleDeck()
    {
        var models = new List<CardModel>();

        for (var copy = 0; copy < 2; copy++)
        {
            foreach (CardSuit suit in Enum.GetValues(typeof(CardSuit)))
            {
                foreach (CardRank rank in Enum.GetValues(typeof(CardRank)))
                {
                    models.Add(new CardModel(suit, rank));
                }
            }
        }

        for (var i = models.Count - 1; i > 0; i--)
        {
            var rnd = UnityEngine.Random.Range(0, i + 1);
            (models[i], models[rnd]) = (models[rnd], models[i]);
        }

        foreach (var model in models)
        {
            var card = Instantiate(cardPrefab, deckContainer.cardHolder);
            card.Initialize(model, faceUp: false);
            deckContainer.AddCardInstant(card);
        }
    }

    public bool CanStartDrag(CardView card)
    {
        if (_isBusy || card.CurrentContainer == null) return false;

        return card.CurrentContainer.type switch
        {
            ContainerType.Deck => deckContainer.Cards.Count > 0 && deckContainer.Cards.Contains(card),
            ContainerType.Hand => true,
            ContainerType.Board => true,
            ContainerType.Discard => discardContainer.Cards.Count > 0 && discardContainer.Cards.Contains(card),
            _ => false
        };
    }

    public async UniTask HandleCardDropAsync(CardView card, CardContainer origin, CardContainer target, int returnIndex)
    {
        _isBusy = true;

        if (target == null || target == origin)
        {
            await origin.AddCardAnimatedAsync(card, returnIndex, _destroyToken);
            _isBusy = false;
            return;
        }

        switch (origin.type)
        {
            case ContainerType.Deck when target.type == ContainerType.Hand:
            {
                if (handContainer.Cards.Count < maxHandSize)
                {
                    await handContainer.AddCardAnimatedAsync(card, -1, _destroyToken);
                    SetStatus($"Взята карта: {FormatCardName(card.Model)}");
                }
                else
                {
                    SetStatus($"В руке нет места (максимум {maxHandSize} карты)");
                    await origin.AddCardAnimatedAsync(card, returnIndex, _destroyToken);
                }

                break;
            }
            case ContainerType.Hand when target.type == ContainerType.Board:
                await boardContainer.AddCardAnimatedAsync(card, -1, _destroyToken);
                await ResolveBattleOnBoardAsync(card);
                break;
            case ContainerType.Hand when target.type == ContainerType.Discard:
                await discardContainer.AddCardAnimatedAsync(card, -1, _destroyToken);
                SetStatus($"Сброшен {FormatCardName(card.Model)}. Берём замену...");
                await UniTask.Delay(250, cancellationToken: _destroyToken);
                await DrawTopCardToHandAsync();
                SetStatus("Ваш ход: выберите карту для атаки");
                break;
            case ContainerType.Discard when target.type == ContainerType.Deck:
                await deckContainer.AddCardAnimatedAsync(card, -1, _destroyToken);
                await RecycleDiscardToDeckAsync();
                SetStatus("Сброшенные карты вернулись в колоду!");
                break;
            case ContainerType.Board when target.type == ContainerType.Discard:
                await discardContainer.AddCardAnimatedAsync(card, -1, _destroyToken);
                SetStatus("Карта отправлена в сброс");
                break;
            default:
                SetStatus("Сюда карту положить нельзя");
                await origin.AddCardAnimatedAsync(card, returnIndex, _destroyToken);
                break;
        }

        _isBusy = false;
    }

    private async UniTask ResolveBattleOnBoardAsync(CardView playerCard)
    {
        SetStatus($"Вы сыграли: {FormatCardName(playerCard.Model)}. Ход противника...");
        await UniTask.Delay(400, cancellationToken: _destroyToken);

        if (deckContainer.Cards.Count == 0)
        {
            await RecycleDiscardToDeckAsync();
        }

        if (deckContainer.Cards.Count == 0)
        {
            SetStatus("В колоде закончились карты. Ничья в раунде!");
            boardContainer.RemoveCardListReference(playerCard);
            await discardContainer.AddCardAnimatedAsync(playerCard, -1, _destroyToken);
            return;
        }

        var enemyCard = deckContainer.Cards[^1];
        deckContainer.RemoveCardListReference(enemyCard);
        await boardContainer.AddCardAnimatedAsync(enemyCard, -1, _destroyToken);

        await UniTask.Delay(650, cancellationToken: _destroyToken);

        var result = CompareCards(playerCard.Model, enemyCard.Model);
        switch (result)
        {
            case > 0:
                _playerScore++;
                SoundManager.Instance?.PlayWin();
                SetStatus($"Победа! Ваш {FormatCardName(playerCard.Model)} побеждает {FormatCardNameGenitive(enemyCard.Model)}!");
                break;
            case < 0:
                _enemyScore++;
                SoundManager.Instance?.PlayLose();
                SetStatus($"Поражение: {FormatCardName(enemyCard.Model)} соперника оказался сильнее.");
                break;
            default:
                SetStatus("Боевая ничья! Силы стихий равны.");
                break;
        }

        UpdateScoreUI();
        await UniTask.Delay(1100, cancellationToken: _destroyToken);

        boardContainer.RemoveCardListReference(playerCard);
        boardContainer.RemoveCardListReference(enemyCard);

        await UniTask.WhenAll(
            discardContainer.AddCardAnimatedAsync(playerCard, -1, _destroyToken),
            discardContainer.AddCardAnimatedAsync(enemyCard, -1, _destroyToken)
        );

        if (handContainer.Cards.Count == 0)
        {
            if (deckContainer.Cards.Count == 0)
                await RecycleDiscardToDeckAsync();

            await DrawTopCardToHandAsync();
        }

        SetStatus("Ваш ход: выберите карту для атаки");
    }

    private int CompareCards(CardModel p, CardModel e)
    {
        if (p.rank != e.rank)
            return p.rank > e.rank ? 1 : -1;

        if (p.suit == e.suit)
            return 0;

        var playerSuitAdvantage =
            (p.suit == CardSuit.Fire && e.suit == CardSuit.Earth) ||
            (p.suit == CardSuit.Earth && e.suit == CardSuit.Air) ||
            (p.suit == CardSuit.Air && e.suit == CardSuit.Water) ||
            (p.suit == CardSuit.Water && e.suit == CardSuit.Fire);

        return playerSuitAdvantage ? 1 : -1;
    }

    private async UniTask DrawTopCardToHandAsync()
    {
        if (deckContainer.Cards.Count == 0 || handContainer.Cards.Count >= maxHandSize) return;

        var topCard = deckContainer.Cards[^1];
        deckContainer.RemoveCardListReference(topCard);
        await handContainer.AddCardAnimatedAsync(topCard, -1, _destroyToken);
    }

    private async UniTask RecycleDiscardToDeckAsync()
    {
        if (discardContainer.Cards.Count == 0) return;

        SetStatus("Перетасовываем сброс обратно в колоду...");
        var cardsToRecycle = new List<CardView>(discardContainer.Cards);
        discardContainer.Cards.Clear();

        foreach (var c in cardsToRecycle)
        {
            await deckContainer.AddCardAnimatedAsync(c, -1, _destroyToken);
        }
    }

    public async UniTaskVoid DrawCardByClickAsync()
    {
        if (_isBusy) return;
        if (handContainer.Cards.Count >= maxHandSize)
        {
            SetStatus($"В руке уже максимум карт ({maxHandSize})");
            return;
        }

        _isBusy = true;
        await DrawTopCardToHandAsync();
        _isBusy = false;
    }

    public async UniTaskVoid PlayCardFromHandByClickAsync(CardView card)
    {
        if (_isBusy || card == null || card.CurrentContainer != handContainer) return;

        _isBusy = true;
        handContainer.RemoveCardListReference(card);
        await boardContainer.AddCardAnimatedAsync(card, -1, _destroyToken);
        await ResolveBattleOnBoardAsync(card);
        _isBusy = false;
    }

    public async UniTaskVoid RecycleDiscardByClickAsync()
    {
        if (_isBusy) return;
        if (discardContainer.Cards.Count == 0)
        {
            SetStatus("Стопка сброса пуста");
            return;
        }

        _isBusy = true;
        await RecycleDiscardToDeckAsync();
        SetStatus("Колода пополнена из сброса!");
        _isBusy = false;
    }

    private void UpdateScoreUI()
    {
        if (scoreText != null)
            scoreText.text = $"Игрок: {_playerScore}  |  Противник: {_enemyScore}";
    }

    private void SetStatus(string message)
    {
        if (statusText != null)
            statusText.text = message;
    }

    private static string FormatCardName(CardModel card)
    {
        var rank = card.rank switch
        {
            CardRank.Servant => "Слуга",
            CardRank.Knight => "Рыцарь",
            CardRank.Lord => "Владыка",
            _ => "Воин"
        };

        var suit = card.suit switch
        {
            CardSuit.Fire => "Огня",
            CardSuit.Earth => "Земли",
            CardSuit.Air => "Воздуха",
            CardSuit.Water => "Воды",
            _ => ""
        };

        return $"{rank} {suit}";
    }

    private static string FormatCardNameGenitive(CardModel card)
    {
        var rank = card.rank switch
        {
            CardRank.Servant => "Слугу",
            CardRank.Knight => "Рыцаря",
            CardRank.Lord => "Владыку",
            _ => "Воина"
        };

        var suit = card.suit switch
        {
            CardSuit.Fire => "Огня",
            CardSuit.Earth => "Земли",
            CardSuit.Air => "Воздуха",
            CardSuit.Water => "Воды",
            _ => ""
        };

        return $"{rank} {suit}";
    }
}