using System.Collections.Generic;
using game;
using UnityEngine;

public class BaseMarketSectionUI : MonoBehaviour
{
    public static string SectionPrefab => "UI/Templates/DefaultSection";
    
    private static string PageTemplate => "UI/Templates/PageTemplate";

    public bool NeedPurchaseConfirmation { get; set; }
    private BaseShop Shop { get; set; }

    private ShopPageUI _pageTemplate;
    private Transform _pagesContainer;
    private List<ShopPageUI> _pages = new List<ShopPageUI>();

    private ConfBaseShopItem _selectedItem;
    private BaseItemPreviewer _itemPreviewer;

    private ConfirmationWindow _confirmationWindow;                                           
    private ItemClickResult _itemClickResult;

    public void Init()
    {
        _pagesContainer = transform.Find("View/Content");
        _pageTemplate = Assets.Load<ShopPageUI>(PageTemplate);
    }

    public void SetShop(BaseShop shop)
    {
        Shop = shop;
        FillItems();
    }

    public void SetPreviewContainer(Transform container)
    {
        _itemPreviewer = FactorySectionItemPreview.CreateItemPreview(Shop.Type);
        _itemPreviewer.gameObject.SetParent(container);

        SyncShopItemPreview();
    }

    private void FillItems()
    {
        int itemsCount = Shop.ItemsCount;
        for (int i = 0; i < itemsCount; i++)
            AddItem(Shop.GetItemAt(i));

        //  SyncShopItemsView();
    }

    private void AddItem(ConfBaseShopItem confItem)
    {
        ShopPageUI pageForItem = GetOrCreatePageForNextItem();
        pageForItem.SetItemStateGetter(Shop.GetItemShopState);
        pageForItem.SetItemClickAction(OnItemClick);
        pageForItem.AddItem(confItem);
    }

    private ShopPageUI GetOrCreatePageForNextItem()
    {
        if (_pages.Count > 0 && _pages.Last().CanAddItem())
            return _pages.Last();

        ShopPageUI page = Instantiate(_pageTemplate, _pagesContainer);
        page.Init();
        page.gameObject.SetActive(true);
        _pages.Add(page);
        return page;
    }

    private void SyncSelectedItemConfInUI()
    {
        foreach (ShopPageUI page in _pages)
        {
            if (page.HaveItemWithConf(_selectedItem))
                page.SetSelectedItem(_selectedItem);
            else
                page.ResetSelectedItem();
        }
    }

    private bool TryGetSelectedItem(out uint itemId)
    {
        foreach (ShopPageUI page in _pages)
        {
            if (page.TryGetSelectedItemId(out itemId))
                return true;
        }

        itemId = 0;
        return false;
    }

    private void OnItemClick(ConfBaseShopItem itemConf, ItemClickResult result)
    {
        ItemSaveState itemState = Shop.GetStateForItem(itemConf);

        EnumClickResult clickResult = EnumClickResult.None;
        if (TryGetSelectedItem(out uint itemId))
        {
            bool wasSelected = itemConf.itemAmount.protoId == itemId;
            if (wasSelected)
            {
                if (itemState.IsEquipped)
                    clickResult = EnumClickResult.None;
                else if (itemState.IsHas)
                {
                    Shop.TryEquipItem(itemConf);
                    clickResult = EnumClickResult.Equipped;
                }
                else
                {
                    if (Shop.HaveMoney(itemConf.price))
                    {
                        if (NeedPurchaseConfirmation)
                        {
                            _itemClickResult = result;
                            OpenConfirmationWindow(itemConf);
                            return;
                        }
                        
                        PurchaseAndEquipItem(itemConf);
                        clickResult = EnumClickResult.Purchased;
                    }
                    else
                        clickResult = EnumClickResult.NoMoney;
                }
            }
            else if (itemState.IsHas && !itemState.IsEquipped)
            {
                Shop.TryEquipItem(itemConf);
                clickResult = EnumClickResult.Equipped;
            }
        }
        else
        {
            if (itemState.IsEquipped)
                clickResult = EnumClickResult.None;
            else if (itemState.IsHas)
            {
                Shop.TryEquipItem(itemConf);
                clickResult = EnumClickResult.Equipped;
            }
        }

        result?.Invoke(clickResult);
        ChangeSelectedItem(itemConf);
        SyncShopItemsView();
    }

    private void OpenConfirmationWindow(ConfBaseShopItem purchasingItem)
    {
        _confirmationWindow = UI.GetOrCreateWindow<ConfirmationWindow>();
        _confirmationWindow.SetItemForBuy(purchasingItem);
        _confirmationWindow.OnHaveResult += ConfirmationWindowResult;
        _confirmationWindow.Show();
    }

    private void ConfirmationWindowResult(ConfBaseShopItem item, EnumClickResult result)
    {
        _confirmationWindow.OnHaveResult -= ConfirmationWindowResult;
        if (result == EnumClickResult.Purchased)
            PurchaseAndEquipItem(item);
        
        _itemClickResult?.Invoke(result);
    }

    private void PurchaseAndEquipItem(ConfBaseShopItem item)
    {
        Shop.TryBuyItem(item);
        Shop.TryEquipItem(item);
        SyncShopItemsView();
    }

    private void SelectEquipmentOrFirstItem()
    {
        ConfBaseShopItem selectionItem = GetEquipmentItem();
        if (selectionItem == null)
            selectionItem = Shop.Items[0];

        ChangeSelectedItem(selectionItem);
    }

    private ConfBaseShopItem GetEquipmentItem()
    {
        foreach (var item in Shop.Items)
        {
            if (Shop.GetItemShopState(item) == ItemShopState.Equipment)
                return item;
        }

        return null;
    }

    private void ChangeSelectedItem(ConfBaseShopItem itemConf, bool withUpdate = true)
    {
        _selectedItem = itemConf;

        SyncShopItemPreview();
        if (withUpdate)
            SyncSelectedItemConfInUI();
    }

    private void SyncShopItemsView()
    {
        foreach (ShopItemUI itemUI in Items())
            itemUI.SyncView();
    }

    private void SyncShopItemPreview()
    {
        if (_itemPreviewer != null && _selectedItem != null)
            _itemPreviewer.ChangeItem(_selectedItem, NeedShadedItem(_selectedItem));
    }

    private IEnumerable<ShopItemUI> Items()
    {
        foreach (var page in _pages)
        {
            foreach (var item in page.Items)
                yield return item;
        }
    }

    public void Open()
    {
        gameObject.SetActive(true);

        SelectEquipmentOrFirstItem();
        if (_itemPreviewer != null)
            _itemPreviewer.Show();
    }

    public void Hide()
    {
        gameObject.SetActive(false);

        if (_itemPreviewer != null)
            _itemPreviewer.Hide();
    }

    public void Close()
    {
        if (_itemPreviewer != null)
            Destroy(_itemPreviewer);
    }

    private bool NeedShadedItem(ConfBaseShopItem item)
    {
        return Shop.GetItemShopState(item) == ItemShopState.NotPurchased &&
               Shop.HaveMoney(item.price);
    }
}