using UnityEngine;
using UnityEngine.Events;

[RequireComponent(typeof(Collider))]
public class Slot : MonoBehaviour
{
    public ItemType requiredItemType;
    public bool isOccupied;

    [Header("Visuals")]
    public Material normalMaterial;
    public Material validPreviewMaterial;
    public Material invalidPreviewMaterial;
    public Material successMaterial;

    [Header("Placement")]
    public Transform snapPoint;
    public UnityEvent onItemPlaced = new UnityEvent();

    private Renderer slotRenderer;
    private DraggableObject placedItem;

    private void Awake()
    {
        slotRenderer = GetComponent<Renderer>();

        if (slotRenderer != null && normalMaterial == null)
        {
            normalMaterial = slotRenderer.sharedMaterial;
        }
    }

    private void Start()
    {
        ApplyMaterial(normalMaterial);
    }

    public bool CanAccept(DraggableObject item)
    {
        return item != null && !isOccupied && item.itemType == requiredItemType;
    }

    public void PlaceItem(DraggableObject item)
    {
        if (!CanAccept(item))
        {
            ShowPreview(item);
            return;
        }

        isOccupied = true;
        placedItem = item;

        // SnapPoint задаёт точку фиксации предмета над плоскостью слота.
        Vector3 targetPosition = snapPoint != null ? snapPoint.position : transform.position + Vector3.up * 0.35f;
        item.LockToSlot(targetPosition);

        ApplyMaterial(successMaterial);
        onItemPlaced.Invoke();
    }

    public void ResetSlot()
    {
        isOccupied = false;
        placedItem = null;
        ApplyMaterial(normalMaterial);
    }

    public void ShowPreview(DraggableObject item)
    {
        if (isOccupied)
        {
            ApplyMaterial(successMaterial);
            return;
        }

        ApplyMaterial(CanAccept(item) ? validPreviewMaterial : invalidPreviewMaterial);
    }

    public void ClearPreview()
    {
        ApplyMaterial(isOccupied ? successMaterial : normalMaterial);
    }

    private void ApplyMaterial(Material material)
    {
        if (slotRenderer != null && material != null)
        {
            slotRenderer.sharedMaterial = material;
        }
    }
}