UIManager - Part 1

using UnityEngine;
using UnityEngine.UI;
using System.Collections.Generic;

public class UIManager : MonoBehaviour
{
    public static UIManager Instance { get; private set; }

    public GameObject inventoryPanel;
    public GameObject inventoryPrompt;
    public Text promptText;
    public Button yesButton;
    public Button noButton;
    public Button closeButton;
    public Transform inventorySlotParent;

    private InventorySystem inventorySystem;
    private Item currentStorageItem;
    private StorageSystem storageSystem;

    private void Awake()
    {
        if (Instance == null)
        {
            Instance = this;
        }
        else if (Instance != this)
        {
            gameObject.SetActive(false);
            return;
        }
    }

    private void Start()
    {
        inventorySystem = InventorySystem.Instance;
        storageSystem = StorageSystem.Instance;
        closeButton.onClick.AddListener(CloseInventory);
    }

    public void ShowInventoryPrompt(Item storageItem)
    {
        if (storageItem == null)
        {
            Debug.LogError("<color=red>Attempted to show inventory prompt for null storage item.</color>");
            return;
        }

        inventoryPrompt.SetActive(true);
        promptText.text = $"Open {storageItem.itemName}?";
        yesButton.onClick.RemoveAllListeners();
        yesButton.onClick.AddListener(() => OpenInventory(storageItem));
        noButton.onClick.RemoveAllListeners();
        noButton.onClick.AddListener(ClosePrompt);
    }

    private void OpenInventory(Item storageItem)
    {
        inventoryPrompt.SetActive(false);
        inventoryPanel.SetActive(true);
        currentStorageItem = storageItem;
        PopulateInventoryUI(storageItem);
        Debug.Log($"<color=green>Opened inventory for {storageItem.itemName}</color>");
    }

    private void PopulateInventoryUI(Item storageItem)
    {
        ClearInventoryUI();
        List<Item> storageInventory = storageSystem.GetStorageInventory(storageItem);
        for (int i = 0; i < inventorySlotParent.childCount; i++)
        {
            if (i < storageInventory.Count)
            {
                UpdateInventorySlot(inventorySlotParent.GetChild(i).gameObject, storageInventory[i]);
            }
            else
            {
                ClearInventorySlot(inventorySlotParent.GetChild(i).gameObject);
            }
        }
    }

    private void UpdateInventorySlot(GameObject slotObject, Item item)
    {
        Image iconImage = slotObject.GetComponentInChildren<Image>();
        iconImage.sprite = item.icon;
        iconImage.enabled = true;
        Button slotButton = slotObject.GetComponent<Button>();
        slotButton.onClick.RemoveAllListeners();
        slotButton.onClick.AddListener(() => EquipItemFromInventory(item));
    }

    private void ClearInventorySlot(GameObject slotObject)
    {
        Image iconImage = slotObject.GetComponentInChildren<Image>();
        iconImage.sprite = null;
        iconImage.enabled = false;
        Button slotButton = slotObject.GetComponent<Button>();
        slotButton.onClick.RemoveAllListeners();
    }

    private void EquipItemFromInventory(Item item)
    {
        if (inventorySystem.leftHandItem == null)
        {
            inventorySystem.EquipItem(item, true, item.isTwoHanded);
        }
        else if (inventorySystem.rightHandItem == null && !item.isTwoHanded)
        {
            inventorySystem.EquipItem(item, false, false);
        }
        else
        {
            Debug.Log("<color=orange>Cannot equip item. Hands are full.</color>");
            return;
        }

        inventorySystem.RemoveItemFromStorage(currentStorageItem, item);
        PopulateInventoryUI(currentStorageItem);
        Debug.Log($"<color=green>Equipped {item.itemName} from inventory</color>");
    }

    private void ClearInventoryUI()
    {
        foreach (Transform child in inventorySlotParent)
        {
            ClearInventorySlot(child.gameObject);
        }
    }

    private void ClosePrompt()
    {
        inventoryPrompt.SetActive(false);
    }

    private void CloseInventory()
    {
        inventoryPanel.SetActive(false);
        currentStorageItem = null;
    }
}