InventoryManager

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;

public class InventoryManager : MonoBehaviour
{
    [SerializeField] private PlayerInventory playerInventory;
    [SerializeField] private GameObject inventorySlotPrefab;
    [SerializeField] private GameObject scrollViewContent;
    [SerializeField] private TextMeshProUGUI description;
    [SerializeField] private GameObject useButton;

    private InventoryItem selectedItem;
    private List<InventorySlot> slots = new List<InventorySlot>();
    private int selectedIndex = 0;

    public void SetTextAndButton(string description, bool buttonActive)
    {
        this.description.text = description;
        useButton.SetActive(buttonActive);
    }

    private void MakeInventorySlots()
    {
        if(playerInventory != null)
        {
            foreach(InventoryItem item in playerInventory.Inventory)
            {
                InventorySlot slot = Instantiate(inventorySlotPrefab).GetComponent<InventorySlot>();
                slot.transform.SetParent(scrollViewContent.transform);
                slot.Setup(item, this);

                slots.Add(slot);
            }
        }
    }

    void Start()
    {
        MakeInventorySlots();
        SetTextAndButton("", false);
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.RightArrow))
        {
            if (selectedIndex < slots.Count - 1)
            {
                selectedIndex++;
                ChangeSelectedItem(slots[selectedIndex]);
            }
        }
        else if (Input.GetKeyDown(KeyCode.LeftArrow))
        {
            if (selectedIndex > 0)
            {
                selectedIndex--;
                ChangeSelectedItem(slots[selectedIndex]);
            }
        }
    }

    public void ChangeSelectedItem(InventorySlot slot)
    {
        for (int i = 0; i < slots.Count; i++)
        {
            if (slots[i] != slot)
            {
                slots[i].IsSelected = false;
                slots[i].SelectedSprite.enabled = false;
            }
            else
            {
                selectedIndex = i;
                slots[i].IsSelected = true;
                slots[i].SelectedSprite.enabled = true;
            }
        }

        SetupDescription(slot.Item);
    }

    private void SetupDescription(InventoryItem item)
    {
        selectedItem = item;
        this.description.text = item.ItemDescription;
        useButton.SetActive(item.Usable);
    }

    public void Use()
    {
        if(selectedItem != null)
        {
            selectedItem.Use();
        }
    }
}