using UnityEngine;
using System.Collections.Generic;

public class Inventory : MonoBehaviour
{
    // A fixed array of 10 slots
    [Header("Exactly 10 Slots")]
    public Item[] slots = new Item[10];

    public int currentSlot = 0;

    [SerializeField] private Transform handSlot;
    private GameObject currentSpawnedItem;

    void Update()
    {
        float scroll = Input.GetAxis("Mouse ScrollWheel");
        if (scroll > 0f)
        {
            SelectPreviousSlot();
        }
        else if (scroll < 0f)
        {
            SelectNextSlot();
        }
    }

    /// <summary>
    /// Adds an item to the first available slot (if any).
    /// </summary>
    public void AddItem(Item newItem)
    {
        for (int i = 0; i < slots.Length; i++)
        {
            if (slots[i] == null)
            {
                slots[i] = newItem;
                break;
            }
        }
        // Optional: if no item is equipped yet, equip slot 0, etc.
        // if (currentSpawnedItem == null) EquipSlot(0);
    }

    private void SelectNextSlot()
    {
        currentSlot = (currentSlot + 1) % slots.Length;
        EquipSlot(currentSlot);

        // Force the UI to re-check which slot is active
        var ui = FindObjectOfType<InventoryUI>();
        if (ui != null)
        {
            ui.RefreshUI();
        }
    }

    private void SelectPreviousSlot()
    {
        currentSlot = (currentSlot - 1 + slots.Length) % slots.Length;
        EquipSlot(currentSlot);

        var ui = FindObjectOfType<InventoryUI>();
        if (ui != null)
        {
            ui.RefreshUI();
        }
    }

    public void EquipSlot(int slotIndex)
    {
        if (currentSpawnedItem != null)
        {
            Destroy(currentSpawnedItem);
        }

        Item itemInSlot = slots[slotIndex];
        GameObject prefab = itemInSlot != null ? itemInSlot.GetPrefab() : null;

        if (prefab != null && handSlot != null)
        {
            currentSpawnedItem = Instantiate(prefab, handSlot.position, handSlot.rotation, handSlot);
            currentSpawnedItem.transform.localPosition = Vector3.zero;
            currentSpawnedItem.transform.localRotation = Quaternion.identity;
        }
        else
        {
            currentSpawnedItem = null;
        }
    }
}