using UnityEngine;

/// <summary>
/// ScriptableObject defining item properties.
/// Implements IUsableItem and IEquippableItem for extensibility.
/// </summary>
[CreateAssetMenu(fileName = "New Item", menuName = "Inventory/Item")]
public class ItemData : ScriptableObject, IUsableItem, IEquippableItem
{
    [Header("Basic Info")]
    public int itemID;
    public string itemName;
    public Sprite icon;
    [TextArea] public string description;

    [Header("Stack & Weight")]
    public float weight = 1f;
    public int maxStack = 99;

    [Header("Visual Source")]
    [Tooltip("Original prefab for dropped item visuals")]
    public GameObject originalBlockPrefab;

    [Header("Item Behavior")]
    [Tooltip("Defines what happens when the item is used")]
    public ItemBehavior behavior;

    [Header("Equipment Settings")]
    [Tooltip("Whether this item can be equipped (shows in hand)")]
    public bool isEquippable;
    [Tooltip("Prefab spawned in player's hand when equipped")]
    public GameObject equipmentPrefab;
    public Vector3 equipPositionOffset;
    public Vector3 equipRotationOffset;
    [Tooltip("Name of the transform to attach equipment to")]
    public string attachmentPointName = "ToolAnchor";

    #region IUsableItem Implementation

    public bool IsConsumable => behavior != null && behavior.IsConsumable;

    public bool CanUse(GameObject user, GameObject target)
    {
        return behavior != null && behavior.CanUse(user, target);
    }

    public void Use(GameObject user, GameObject target)
    {
        if (behavior != null)
        {
            behavior.Use(user, target);
        }
    }

    public ActionDescriptor GetUseAction()
    {
        return behavior?.GetActionDescriptor();
    }

    #endregion

    #region IEquippableItem Implementation

    public GameObject GetEquipmentPrefab() => equipmentPrefab;
    public Vector3 GetPositionOffset() => equipPositionOffset;
    public Vector3 GetRotationOffset() => equipRotationOffset;
    public string GetAttachmentPointName() => attachmentPointName;

    public Transform FindAttachmentPoint(GameObject user)
    {
        if (string.IsNullOrEmpty(attachmentPointName))
            return user.transform;

        var transforms = user.GetComponentsInChildren<Transform>();
        foreach (var t in transforms)
        {
            if (t.name == attachmentPointName)
                return t;
        }

        return user.transform;
    }

    #endregion

    #region Utility Properties

    /// <summary>
    /// Check if this item has any usable behavior.
    /// </summary>
    public bool HasBehavior => behavior != null;

    /// <summary>
    /// Check if this item can be equipped.
    /// </summary>
    public bool CanBeEquipped => isEquippable && equipmentPrefab != null;

    #endregion

    #region Utility Methods

    /// <summary>
    /// Get display name for UI.
    /// </summary>
    public string GetDisplayName() => string.IsNullOrEmpty(itemName) ? name : itemName;

    /// <summary>
    /// Get description for UI.
    /// </summary>
    public string GetDescription() => description;

    /// <summary>
    /// Calculate total weight for a stack.
    /// </summary>
    public float GetStackWeight(int count) => weight * count;

    #endregion
}