using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 拆家版固定八卡组、四张手牌轮转管理器。
/// </summary>
public class BattleDeckCycle : MonoBehaviour
{
    public static BattleDeckCycle Instance { get; private set; }

    [SerializeField] private Transform cardRoot;
    [SerializeField] private int visibleSlotCount = 4;
    [SerializeField] private string[] deckDataNames =
    {
        "人类士兵Data", "弓箭手Data", "盾卫Data", "精锐士兵Data",
        "法师Data", "狂暴狼人Data", "石巨人Data", "弓箭猎人Data"
    };

    private readonly List<CharacterData> deck = new List<CharacterData>();
    private readonly List<CharacterData> hand = new List<CharacterData>();
    private readonly Queue<CharacterData> drawQueue = new Queue<CharacterData>();
    private SummonCardButton[] buttons;

    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }
        Instance = this;
        BuildDeck();
    }

    private void Start()
    {
        if (cardRoot == null)
            cardRoot = GameObject.Find("角色卡片")?.transform;

        buttons = cardRoot != null
            ? cardRoot.GetComponentsInChildren<SummonCardButton>(true)
            : FindObjectsOfType<SummonCardButton>(true);

        System.Array.Sort(buttons, (a, b) => a.summonSlot.CompareTo(b.summonSlot));
        HideExtraSlots();
        hand.Clear();
        drawQueue.Clear();

        for (int i = 0; i < visibleSlotCount && i < deck.Count; i++)
            hand.Add(deck[i]);
        for (int i = visibleSlotCount; i < deck.Count; i++)
            drawQueue.Enqueue(deck[i]);

        RefreshAllCards();
    }

    public CharacterData GetCard(int slot)
    {
        int index = slot - 1;
        return index >= 0 && index < hand.Count ? hand[index] : null;
    }

    public bool TryPlay(int slot)
    {
        CharacterData card = GetCard(slot);
        if (card == null || card.unitPrefab == null || CastleSpawnManager.Instance == null)
            return false;

        if (!CastleSpawnManager.Instance.TrySpawn(card, 0))
            return false;

        int index = slot - 1;
        CharacterData played = hand[index];
        hand[index] = drawQueue.Dequeue();
        drawQueue.Enqueue(played);
        RefreshAllCards();
        return true;
    }

    private void BuildDeck()
    {
        deck.Clear();
        foreach (string dataName in deckDataNames)
        {
            CharacterData data = Resources.Load<CharacterData>("Data/" + dataName);
            if (data == null)
            {
                Debug.LogWarning($"卡组缺少角色数据: Resources/Data/{dataName}.asset");
                continue;
            }
            deck.Add(data);
        }
    }

    private void HideExtraSlots()
    {
        foreach (var button in buttons)
        {
            if (button != null && button.summonSlot > visibleSlotCount)
                button.gameObject.SetActive(false);
        }
    }

    private void RefreshAllCards()
    {
        if (buttons == null) return;
        foreach (var button in buttons)
        {
            if (button == null || button.summonSlot > visibleSlotCount) continue;
            button.SetDeckCharacter(GetCard(button.summonSlot));
        }
    }
}