using UnityEngine;
using System;

/// <summary>
/// 金币管理器，全局单例
/// </summary>
public class GoldManager : MonoBehaviour
{
    public static GoldManager Instance { get; private set; }

    [Header("金币设置")]
    [SerializeField] private int initialGold = 500;
    [SerializeField] private int currentGold = 500;

    /// <summary>
    /// 当前金币数量（只读）
    /// </summary>
    public int CurrentGold => currentGold;

    /// <summary>
    /// 金币变化事件（参数：新的金币数量）
    /// </summary>
    public event Action<int> OnGoldChanged;

    private void Awake()
    {
        // 单例模式
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }
        Instance = this;
    }

    private void Start()
    {
        currentGold = initialGold;
        OnGoldChanged?.Invoke(currentGold);
    }

    /// <summary>
    /// 增加金币
    /// </summary>
    public void AddGold(int amount)
    {
        if (amount <= 0) return;

        currentGold += amount;
        OnGoldChanged?.Invoke(currentGold);
        Debug.Log($"获得金币 +{amount}，当前金币: {currentGold}");
    }

    /// <summary>
    /// 尝试消费金币，如果金币足够则扣除并返回 true，否则返回 false
    /// </summary>
    public bool TrySpendGold(int amount)
    {
        if (amount <= 0)
        {
            Debug.LogWarning("消费金币数量必须大于0");
            return false;
        }

        if (currentGold < amount)
        {
            Debug.LogWarning($"金币不足！需要 {amount}，当前只有 {currentGold}");
            return false;
        }

        currentGold -= amount;
        OnGoldChanged?.Invoke(currentGold);
        Debug.Log($"消费金币 -{amount}，当前金币: {currentGold}");
        return true;
    }

    /// <summary>
    /// 检查是否有足够的金币
    /// </summary>
    public bool HasEnoughGold(int amount)
    {
        return currentGold >= amount;
    }
}