using UnityEngine;
using UnityEngine.UI;
using DG.Tweening; // DOTween

public class ManaManager : MonoBehaviour
{
    [Header("Mana")]
    public float maxMana = 100f;
    public float mana = 100f;

    [Header("Regen")]
    public bool enableRegen = true;
    public float regenPerSecond = 8f;
    public float regenDelayAfterSpend = 1.0f;

    [Header("UI")]
    public Image manaFillImage; // or assign an Image with fillAmount

    float regenResumeTime = 0f;

    void Awake()
    {
        mana = Mathf.Clamp(mana, 0, maxMana);
        InitUI();
    }

    void Update()
    {
        if (!enableRegen) return;
        if (Time.time < regenResumeTime) return;
        if (mana >= maxMana) return;

        SetMana(Mathf.Min(maxMana, mana + regenPerSecond * Time.deltaTime));
    }

    public bool Has(float amount) => mana >= amount;

    public bool Spend(float amount)
    {
        if (amount <= 0f) return true;
        if (mana < amount) return false;

        SetMana(mana - amount);
        regenResumeTime = Time.time + Mathf.Max(0f, regenDelayAfterSpend);
        return true;
    }

    public void Refill(float amount)
    {
        if (amount <= 0f) return;
        SetMana(Mathf.Min(maxMana, mana + amount));
    }

    public void SetMax(float newMax, bool keepRatio = true)
    {
        newMax = Mathf.Max(1f, newMax);
        float ratio = maxMana > 0 ? mana / maxMana : 1f;
        maxMana = newMax;
        mana = keepRatio ? Mathf.Clamp01(ratio) * maxMana : Mathf.Min(mana, maxMana);
        InitUI();
    }

    void SetMana(float newValue)
    {
        mana = newValue;
        UpdateUI();
    }

    void InitUI()
    {
        if (manaFillImage)
            manaFillImage.fillAmount = mana / maxMana;
    }

    void UpdateUI()
    {
        if (manaFillImage)
        {
            manaFillImage.DOFillAmount(mana / maxMana, 0.25f).SetEase(Ease.OutCubic);
        }
    }

    // ===== Debug Menu =====
    [ContextMenu("Debug/Spend 10 Mana")]
    void DebugSpend() => Spend(10f);

    [ContextMenu("Debug/Refill 10 Mana")]
    void DebugRefill() => Refill(10f);

    [ContextMenu("Debug/Empty Mana")]
    void DebugEmpty() => Spend(maxMana);
}