InventorySystem - Part 12

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


public class InventorySystem : MonoBehaviour
{
    public static InventorySystem Instance { get; set; }

    public GameObject inventoryScreenUI;

    public List<GameObject> slotList = new List<GameObject>();

    public List<string> itemList = new List<string>();

    private GameObject itemToAdd;

    private GameObject whatSlotToEquip;

    public bool isOpen;

    //public bool isFull;


    //PickUpPopUP
    public GameObject pickupAlert;
    public Text pickupName;
    public Image pickupImage;

    // ItemInfoUI
    public GameObject ItemInfoUI;


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


    void Start()
    {
        isOpen = false;
        PopulateSlotList();

        Cursor.visible = false;
    }

    private void PopulateSlotList()
    {
        foreach (Transform child in inventoryScreenUI.transform)
        {
            if (child.CompareTag("Slot"))
            {
                slotList.Add(child.gameObject);
            }
        }
    }

    void Update()
    {

        if (Input.GetKeyDown(KeyCode.I) && !isOpen)
        {
            inventoryScreenUI.SetActive(true);
            Cursor.lockState = CursorLockMode.None;
            Cursor.visible = true;

            SelectionManager.Instance.DisableSelection();
            SelectionManager.Instance.GetComponent<SelectionManager>().enabled = false;

            isOpen = true;
        }
        else if (Input.GetKeyDown(KeyCode.I) && isOpen)
        {
            inventoryScreenUI.SetActive(false);
            if (!CraftingSystem.Instance.isOpen) {
                Cursor.lockState = CursorLockMode.Locked;
                Cursor.visible = false;

                SelectionManager.Instance.EnableSelection();
                SelectionManager.Instance.GetComponent<SelectionManager>().enabled = true;
            }
            isOpen = false;
        }
    }

    public void AddToInventory(string itemName)
    {

        whatSlotToEquip = FindNextEmptySlot();

        itemToAdd = Instantiate(Resources.Load<GameObject>(itemName), whatSlotToEquip.transform.position, whatSlotToEquip.transform.rotation);
        itemToAdd.transform.SetParent(whatSlotToEquip.transform);


        itemList.Add(itemName);


        TriggerPickupPopUp(itemName, itemToAdd.GetComponent<Image>().sprite);



        ReCalculateList();
        CraftingSystem.Instance.RefreshNeededItems();
    }

    void TriggerPickupPopUp(string itemName, Sprite itemSprite)
    {

        pickupAlert.SetActive(true);
        pickupName.text = itemName;
        pickupImage.sprite = itemSprite;

        StartCoroutine(Calculate());
    }
    IEnumerator Calculate()
    {
        yield return new WaitForSeconds(2f);
        pickupAlert.SetActive(false);
    }
        private GameObject FindNextEmptySlot()
    {
        foreach(GameObject slot in slotList)
        {
            if (slot.transform.childCount == 0)
            {
                return slot;
            }
        }
        return new GameObject();
    }

    public bool CheckIfFull()
    {
        int counter = 0;

        foreach (GameObject slot in slotList)
        {
            if (slot.transform.childCount > 0)
            {
                counter++;
            }
        }

        if (counter == 21)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    public void RemoveItem(string nameToRemove, int amountToRemove)
    {


        int counter = amountToRemove;

        for (var i = slotList.Count - 1; i>=0; i--)
        {

            if (slotList[i].transform.childCount>0)
            {

                if (slotList[i].transform.GetChild(0).name == nameToRemove+"(Clone)" && counter!=0)
                {

                    Destroy(slotList[i].transform.GetChild(0).gameObject);

                    counter--;

                }
            }
        }

        ReCalculateList();
        CraftingSystem.Instance.RefreshNeededItems();

    }

    public void ReCalculateList()
    {
        itemList.Clear();

        foreach (GameObject slot in slotList)
        {
            if (slot.transform.childCount>0)
            {

                string name = slot.transform.GetChild(0).name; //Stone (Clone)
                string str2 = "(Clone)";
                string result = name.Replace(str2, "");

                itemList.Add(result); //Stone
            }
        }
    }

}