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

public class PlayerInventoryUI : MonoBehaviour
{
    [SerializeField] private GameObject uiSlotPrefab;
    [SerializeField] private GameObject[] uiSlots; //Slots for the quick inventory
    [SerializeField] private GameObject inventoryUIObject;
    [SerializeField] private GameObject slotsOptions;
    [SerializeField] private GameObject insertAmountPanelprefab;
    [SerializeField] private Inventory inventory, quickInventory;

    //Inventory settings
    [SerializeField] private float gridSpacingX, gridSpacingY; //the space between each tile of the matrix
    [SerializeField] private int columns = 5;  // Number of columns in the inventory grid
    private int rows;

    public GameObject currentButtonOptions;

    //UI Inventory Matrix Size
    GameObject[,] inventorySlots = null;

    // Start is called before the first frame update
    void Start()
    {
        inventory = GameManager.Instance.PlayerController.InventoryManager.Inventory;
        quickInventory = GameManager.Instance.PlayerController.InventoryManager.QuickInventory;

        CreateInventoryGrid();

        // Populate UI slots with initial data
        for (int i = 0; i < inventory.Capacity; i++)
        {
            UpdateGridUI(i);
        }
        for (int i = 0; i < quickInventory.Capacity; i++)
        {
            UpdateQuickInventoryUI(i);
        }


        inventory.OnSlotChanged += UpdateGridUI;
        inventory.OnSlotsChanged += UpdateGridUI;

        quickInventory.OnSlotChanged += UpdateQuickInventoryUI;
        quickInventory.OnSlotsChanged += UpdateQuickInventoryUI;
    }

    // Update is called once per frame
    void Update()
    {
    
    }

    public void DisplayGrid(bool enable)
    {
        for (int row = 0; row < rows; row++)
        {
            for (int col = 0; col < columns; col++)
            {
                inventorySlots[row, col].SetActive(enable);
            }
        }
    }

    //Creates an inventory grid
    private void CreateInventoryGrid()
    {
        // Get the inventory size from the player
        int inventorySize = inventory.Capacity;

        // Calculate number of rows needed based on the inventory size and number of columns
        rows = Mathf.CeilToInt((float)inventorySize / columns);

        // Initialize the 2D array based on rows and columns
        inventorySlots = new GameObject[rows, columns];

        // Calculate total width and height of the grid
        float gridWidth = columns * gridSpacingX;
        float gridHeight = rows * gridSpacingY;

        // Calculate the starting position for centering the grid
        Vector3 startPosition = new Vector3(-gridWidth / 2 + gridSpacingX / 2, gridHeight / 2 - gridSpacingY / 2, 0);

        // Start drawing the inventory grid
        for (int row = 0; row < rows; row++)
        {
            for (int col = 0; col < columns; col++)
            {
                // Calculate the slot index (linear inventory index)
                int index = row * columns + col;

                // Ensure we don't create extra slots beyond the inventory size
                if (index >= inventorySize) break;

                // Calculate the position for each slot based on row, column, and spacing
                Vector3 position = startPosition + new Vector3(col * gridSpacingX, -row * gridSpacingY, 0);

                // Instantiate the slot at the calculated position
                GameObject slot = Instantiate(uiSlotPrefab, inventoryUIObject.transform);
                slot.GetComponent<RectTransform>().anchoredPosition = position;
                slot.SetActive(false);

                // Store the slot reference in the array
                inventorySlots[row, col] = slot;
            }
        }
    }

    private void UpdateQuickInventoryUI(int index)
    {
        InventorySlot slot = quickInventory.GetSlot(index);

        GameObject inventorySlot = uiSlots[index];

        InventoryButton slotButton = inventorySlot.GetComponent<InventoryButton>();

        slotButton.ChangeData(slot);
    }

    private void UpdateQuickInventoryUI(int indexA, int indexB)
    {
        InventorySlot slotA = quickInventory.GetSlot(indexA);
        InventorySlot slotB = quickInventory.GetSlot(indexB);

        GameObject inventorySlotA = uiSlots[indexA];
        GameObject inventorySlotB = uiSlots[indexB];

        InventoryButton slotButtonA = inventorySlotA.GetComponent<InventoryButton>();
        InventoryButton slotButtonB = inventorySlotB.GetComponent<InventoryButton>();

        //Updates the data of the slots
        slotButtonA.ChangeData(slotA);
        slotButtonB.ChangeData(slotB);
    }

    //Updates a single index
    private void UpdateGridUI(int index)
    {
        Tuple<int, int> gridIndex = CalculateIndexPosition(index);
        InventorySlot slot = inventory.GetSlot(index);

        GameObject inventorySlot = inventorySlots[gridIndex.Item1, gridIndex.Item2];

        InventoryButton slotButton = inventorySlot.GetComponent<InventoryButton>();

        slotButton.ChangeData(slot);
    }

    //Update 2 indexes
    //Used 2 items swap positions on the inventory
    private void UpdateGridUI(int indexA, int indexB)
    {
        //Calculates the index on the grid based on the index of the inventory
        Tuple<int, int> gridIndexA = CalculateIndexPosition(indexA);
        Tuple<int, int> gridIndexB = CalculateIndexPosition(indexB);

        //Get Inventory Data
        InventorySlot slotA = inventory.GetSlot(indexA);
        InventorySlot slotB = inventory.GetSlot(indexB);

        //Get the ui inventorySlots
        GameObject inventorySlotA = inventorySlots[gridIndexA.Item1, gridIndexA.Item2];
        GameObject inventorySlotB = inventorySlots[gridIndexB.Item1, gridIndexB.Item2];

        //Get the inventory button components
        InventoryButton slotButtonA = inventorySlotA.GetComponent<InventoryButton>();
        InventoryButton slotButtonB = inventorySlotB.GetComponent<InventoryButton>();

        //Change the data
        slotButtonA.ChangeData(slotA);
        slotButtonB.ChangeData(slotB);
    }

    //Calculates the index position
    private Tuple<int,int> CalculateIndexPosition(int index)
    {
        //Calculate the column
        int row = index / columns;
        int col = index % columns;
        return Tuple.Create(row, col);
    }
}