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

public class StoreManager : MonoBehaviour
{
    private StoreObject store;
    private List<ProductInstance> products = new List<ProductInstance>();
    private GameObject uiStore;
    public GameObject uiParent;

    public bool isInitialized = false;
    public float widthSpacing = 0.4f;
    public float heightSpacing = 0.5f;

    sealed internal class ProductInstance
    {
        public GameObject ui;
        public ProductObject product;
        public List<GameObject> instances = new List<GameObject>();

        public ProductInstance(GameObject go, ProductObject p)
        {
            ui = go;
            product = p;
        }
    }

    public void SetStoreObject(StoreObject so)
    {
        this.store = so;
    }

    public void OpenStore()
    {
        if (!isInitialized)
            InitializeStore();
        else
            UpdateAllProductsUI();

        uiStore.SetActive(true);
        GameManager.Instance.SetIsUIMenuOpen(true);
    }

    private void InitializeStore()
    {
        uiStore = Instantiate(store.storePrefab, uiParent.transform);
        uiStore.transform.localPosition = new Vector3(0, 0, 5);
        InitializeProductPage();
        isInitialized = true;
    }

    private void InitializeProductPage()
    {
        ProductObject product;
        for (int i = 0; i < store.products.Count; i++)
        {
            product = store.products[i];
            GameObject go = Instantiate(store.productUIPrefab, uiStore.transform);
            go.transform.localPosition = CalculateCardPosition(i);

            ProductInstance pi = new ProductInstance(go, product);
            products.Add(pi);

            go.GetComponent<IProductUI>().SetInformation(products.Count - 1, product.uiName, product.uiDescription, product.uiImage, product.price, IsProductBuyable(pi));
        }
    }

    public void DestroyStore()
    {
        Destroy(uiStore);
        isInitialized = false;
    }

    public void CloseStore()
    {
        uiStore.SetActive(false);
        GameManager.Instance.SetIsUIMenuOpen(false);
    }

    private void UpdateProductUI(GameObject ui, bool isBuyable)
    {
        ui.GetComponent<IProductUI>().UpdateUI(isBuyable);
    }

    private void UpdateAllProductsUI()
    {
        foreach(ProductInstance pi in products)
        {
            pi.ui.GetComponent<IProductUI>().UpdateUI(IsProductBuyable(pi));
        }
    }

    private Vector3 CalculateCardPosition(int index)
    {
        Rect rect = store.productUIPrefab.GetComponent<RectTransform>().rect;
        Rect storeRect = uiStore.GetComponent<RectTransform>().rect;
        int numberPerRow = (int) storeRect.width / (int) (rect.width + widthSpacing);
        int widthIndex = index % numberPerRow;
        int heightIndex = index / numberPerRow;

        int scale = (int) uiStore.GetComponent<CanvasScaler>().referencePixelsPerUnit;

        // FIXME: Algorithm for positionning does not work in all cases (weird behaviour possible if more then 4 products)
        return new Vector3 (
            ((widthIndex * rect.width) + (widthIndex * widthSpacing) + (rect.width / 2) + widthSpacing - (storeRect.width / 2)) * scale,
            ((heightIndex * rect.height) + (heightIndex * heightSpacing) + (rect.height / 3) - heightSpacing) * scale,
            0
        );
    }

    public bool BuyProduct(int id)
    {
        ProductInstance pi = products[id];

        if (!IsProductBuyable(pi))
            return false;

        if (!BillPlayer(pi.product.price))
            return false;

        SpawnProduct(pi);
        UpdateProductUI(pi.ui, IsProductBuyable(pi));

        return true;
    }

    public bool BillPlayer(int price)
    {
        PlayerManagement playerScript = GameObject.FindGameObjectWithTag("Player").GetComponent<PlayerManagement>();
        if(playerScript.BraveryPoints >= price)
        {
            playerScript.DeductPoints(price);
            return true;
        }
        return false;
    }

    private void SpawnProduct(ProductInstance pi)
    {
        TransformAndQuaternionData location = GetNextPossibleLocationForProduct(pi);
        if (location == null)
            return;

        GameObject go = Instantiate(pi.product.prefab, location.position, location.rotation);
        pi.instances.Add(go);
    }

    private TransformAndQuaternionData GetNextPossibleLocationForProduct(ProductInstance pi)
    {
        foreach(TransformAndQuaternionData location in pi.product.spawnLocations)
        {
            if (pi.instances.Find(p => p.transform.position == location.position) == null)
                return location;
        }

        return null;
    }

    private bool IsProductBuyable(ProductInstance pi)
    {
        return pi.instances.Count < pi.product.spawnLocations.Count;
    }
}