using UnityEngine;
using VHS;

public class InventoryUI : MonoBehaviour
{

    Inventory inventory;

    public bool isItemAdded;

    public static InventoryUI inventoryui;

    public GameObject Player;

    public GameObject inventoryUI;

    public Transform slotHolder;
    public InventorySlot[] slots;

    [HideInInspector]
    public bool isOpened;

    void Start()
    {
        isOpened = false;

        inventoryui = this;

        inventory = Inventory.instance;
        inventory.onItemChangedCallback += UpdateUI;

        slots = slotHolder.GetComponentsInChildren<InventorySlot>();
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Tab))
        {
            inventoryUI.SetActive(!inventoryUI.activeSelf);
            isOpened = !isOpened;
        }

        if (isOpened)
        {
            Player.GetComponent<FirstPersonController>().enabled = false;
            Player.GetComponent<CharacterController>().enabled = false;
            Player.GetComponentInChildren<CameraController>().enabled = false;
            Cursor.lockState = CursorLockMode.None;
            Cursor.visible = true;
        }
        else
        {
            Player.GetComponent<FirstPersonController>().enabled = true;
            Player.GetComponent<CharacterController>().enabled = true;
            Player.GetComponentInChildren<CameraController>().enabled = true;
            Cursor.lockState = CursorLockMode.Locked;
            Cursor.visible = false;
        }
    }

    void UpdateUI()
    {
        checkForInventoryItems();
        for (int i = 0; i < slots.Length; i++)
        {
            if (isExists(slots[i].item) && slots[i].item.maxStackAmount > 1 && isThisItem(i) && int.Parse(slots[i].itemAmount.text) < slots[i].item.maxStackAmount)
            {
                int amount = int.Parse(slots[i].itemAmount.text);
                if (slots[i].item != null)
                {
                    slots[i].itemAmount.text = (amount + 1).ToString();
                    Inventory.instance.latestPickup = null;
                }
            }
            else
            {
                for (int c = 0; c < inventory.items.Count; c++)
                {
                    if (!isExists(inventory.items[c]) || (isExists(inventory.items[c]) && inventory.items[c].nextStack() && needToAdd(inventory.items[c])))
                    {
                        slots[findNextEmptySlot()].AddItem(inventory.items[c]);
                        Inventory.instance.latestPickup = null;
                        return;
                    }
                }
            }
        }
    }

    bool needToAdd(Item item)
    {
        for (int i = 0; i < slots.Length; i++)
        {
            if(slots[i].item != null)
            {
                if (int.Parse(slots[i].itemAmount.text) < slots[i].item.maxStackAmount && slots[i].item == item)
                    return false;
            }
        }
        return true;
    }

    int findNextEmptySlot()
    {
        for (int i = 0; i < slots.Length; i++)
        {
            if (slots[i].item == null)
                return i;
        }
        return 0;
    }

    public void checkForInventoryItems()
    {
        for (int i = 0; i < slots.Length; i++)
        {
            if (slots[i].item != null && !inventory.items.Contains(slots[i].item))
                slots[i].RemoveItem();
        }
    }

    public bool isExists(Item item)
    {
        for (int i = 0; i < slots.Length; i++)
        {
            if (slots[i].item != null)
            {
                if (slots[i].item == item)
                {
                    return true;
                }
            }
        }
        return false;
    }

    bool isThisItem(int index)
    {
        if (slots.Length > 0 && slots[index].item != null)
        {
            if (slots[index].item.ItemName.Equals(Inventory.instance.latestPickup))
            {
                return true;
            }
        }
        return false;
    }
}