UIManager - Part 6.1

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

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 okButton;
    public Button closeButton;
    public Button inventoryDoneButton;
    public Transform inventorySlotParent;
    public Transform storageHolder;
    public GameObject moneyDisplay;
    public GameObject doneButton;
    public GameObject itemDetailsPanel;
    public TextMeshProUGUI itemTitleText;
    public TextMeshProUGUI itemDescriptionText;
    public TextMeshProUGUI itemUsesText;
    public TextMeshProUGUI inventoryTitleText;

    [SerializeField] private GameObject itemIconPrefab;

    private InventorySystem inventorySystem;
    private StorageSystem storageSystem;
    private InteractionSystem interactionSystem;
    private PlayerMovement playerMovement;
    private MouseMovement mouseMovement;
    private Item currentStorageItem;
    private Item draggedItem;
    private Transform originalSlot;

    public bool isInventoryOpen = false;

    private void Awake()
    {
        if (Instance == null)
        {
            Instance = this;
        }
        else
        {
            Destroy(gameObject);
        }
    }

    private void Start()
    {
        inventorySystem = InventorySystem.Instance;
        storageSystem = StorageSystem.Instance;
        interactionSystem = FindObjectOfType<InteractionSystem>();
        playerMovement = FindObjectOfType<PlayerMovement>();
        mouseMovement = FindObjectOfType<MouseMovement>();

        if (closeButton != null) closeButton.onClick.AddListener(CloseInventory);
        if (okButton != null)
        {
            okButton.onClick.AddListener(ClosePrompt);
            okButton.gameObject.SetActive(false);
        }
        if (yesButton != null) yesButton.onClick.AddListener(() => HandleBackpackPrompt(true));
        if (noButton != null) noButton.onClick.AddListener(() => HandleBackpackPrompt(false));
        if (inventoryDoneButton != null) inventoryDoneButton.onClick.AddListener(CloseInventory);
    }

    public void ShowInventoryPrompt(Item storageItem)
    {
        currentStorageItem = storageItem;
        inventoryPrompt.SetActive(true);
        promptText.text = storageItem != null ? $"Open {storageItem.itemName}?" : "";
        TogglePlayerControls(false);
    }

    public void UpdatePromptText(string message)
    {
        if (promptText != null)
        {
            promptText.text = message;
        }
    }

    public void ShowOkayButton()
    {
        if (okButton != null)
        {
            okButton.gameObject.SetActive(true);
            yesButton.gameObject.SetActive(false);
            noButton.gameObject.SetActive(false);
        }
    }

    public void OpenInventory(Item storageItem)
    {
        if (storageItem.isBackpack)
        {
            return;
        }

        inventoryPrompt.SetActive(false);
        inventoryPanel.SetActive(true);
        currentStorageItem = storageItem;
        isInventoryOpen = true;

        TransferHeldItemsToStorage();
        PopulateInventoryUI(storageItem);
        TogglePlayerControls(false);

        if (inventoryTitleText != null)
        {
            inventoryTitleText.text = storageItem.itemName;
        }
    }

    private void TransferHeldItemsToStorage()
    {
        if (inventorySystem.leftHandItem != null)
        {
            bool added = storageSystem.AddToStorage(currentStorageItem, inventorySystem.leftHandItem);
            if (added)
            {
                inventorySystem.UnequipItem(true);
                playerMovement.UpdateCarryingAnimations();
            }
        }
        if (inventorySystem.rightHandItem != null)
        {
            bool added = storageSystem.AddToStorage(currentStorageItem, inventorySystem.rightHandItem);
            if (added)
            {
                inventorySystem.UnequipItem(false);
                playerMovement.UpdateCarryingAnimations();
            }
        }
    }

    public void PopulateInventoryUI(Item storageItem)
    {
        UIHelperFunctions.Instance.PopulateInventoryUI(storageItem, inventorySlotParent, storageSystem, this);
    }

    public void UpdateInventorySlot(GameObject slotObject, Item item)
    {
        UIHelperFunctions.Instance.UpdateInventorySlot(slotObject, item, itemIconPrefab, this);
    }

    public void ShowItemDetails(Item item)
    {
        UIHelperFunctions.Instance.ShowItemDetails(item, itemDetailsPanel, itemTitleText, itemDescriptionText, itemUsesText);
    }

    public void HideItemDetails()
    {
        UIHelperFunctions.Instance.HideItemDetails(itemDetailsPanel);
    }

    public void TryEquipItem(Item item)
    {
        UIHelperFunctions.Instance.TryEquipItem(item, inventorySystem, storageSystem, currentStorageItem, interactionSystem, playerMovement, this);
    }

    public void BeginDrag(Transform iconTransform)
    {
        UIHelperFunctions.Instance.BeginDrag(iconTransform, ref draggedItem, ref originalSlot, inventoryPanel);
    }

    public void EndDrag(Transform iconTransform)
    {
        UIHelperFunctions.Instance.EndDrag(iconTransform, draggedItem, originalSlot, inventorySlotParent, currentStorageItem, storageSystem, this);
        draggedItem = null;
    }

    public void ShowError(string message)
    {
        promptText.text = message;
        yesButton.gameObject.SetActive(false);
        noButton.gameObject.SetActive(false);
        okButton.gameObject.SetActive(true);
    }

    public void CloseInventory()
    {
        inventoryPanel.SetActive(false);
        isInventoryOpen = false;
        TogglePlayerControls(true);
    }

    private void TogglePlayerControls(bool enable)
    {
        if (playerMovement != null) playerMovement.enabled = enable;
        if (mouseMovement != null) mouseMovement.enabled = enable;
        SetCursorState(!enable);
    }

    public void ShowBackpackPrompt(Item backpackItem)
    {
        currentStorageItem = backpackItem;
        inventoryPrompt.SetActive(true);
        promptText.text = "Would you like to wear the backpack?";
        yesButton.gameObject.SetActive(true);
        noButton.gameObject.SetActive(true);
        okButton.gameObject.SetActive(false);
        SetCursorState(true);
        FreezePlayerMovement(true);
    }

    public void HandleBackpackPrompt(bool accepted)
    {
        if (accepted)
        {
            interactionSystem.WearBackpack();
        }
        else
        {
            UpdateBackpackPrompt();
        }
    }

    public void UpdateBackpackPrompt()
    {
        promptText.text = "Okay, if you change your mind press E to equip the backpack";
        yesButton.gameObject.SetActive(false);
        noButton.gameObject.SetActive(false);
        okButton.gameObject.SetActive(true);
        SetCursorState(true);
        FreezePlayerMovement(true);
    }

    public void ClosePrompt()
    {
        inventoryPrompt.SetActive(false);
        SetCursorState(false);
        FreezePlayerMovement(false);
        currentStorageItem = null;
    }

    private void SetCursorState(bool visible)
    {
        Cursor.visible = visible;
        Cursor.lockState = visible ? CursorLockMode.None : CursorLockMode.Locked;
    }

    private void FreezePlayerMovement(bool freeze)
    {
        if (playerMovement != null) playerMovement.enabled = !freeze;
        if (mouseMovement != null) mouseMovement.enabled = !freeze;
    }
}

public class ItemReference : MonoBehaviour
{
    public Item item;
}