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

public class ShopUIManager : MonoBehaviour
{
    [Header("Shop Data")]
    public GShopLoader shopLoader;
    
    [Header("UI Panels")]
    public GameObject shopMainPanel;
    public GameObject shopDetailPanel;
    
    [Header("Item Display")]
    public Transform itemContainer; // Parent for item panels
    public GameObject itemPanelPrefab; // Prefab for individual item panels
    
    [Header("Object Pooling")]
    public ItemPanelPool itemPanelPool; // Object pool for item panels
    public bool useObjectPooling = true;
    
    [Header("Category Buttons")]
    public Button[] categoryButtons; // 6 buttons for categories
    
    [Header("Detail Panel Components")]
    public TextMeshProUGUI detailItemName;
    public TextMeshProUGUI detailItemDescription;
    public Image detailItemIcon;
    public TextMeshProUGUI detailItemPrice;
    public TextMeshProUGUI detailItemQuantity;
    public Button buyButton;
    public Button closeDetailButton;
    
    [Header("Main Panel Components")]
    public Button closeShopButton;
    
    private List<GameObject> currentItemPanels = new List<GameObject>();
    private GShopItem selectedItem;
    private int currentCategory = 0; // 0-5 for the 6 merged categories
    
    void Start()
    {
        InitializeUI();
        SetupEventListeners();
        InitializePool();
    }
    
    void InitializePool()
    {
        if (useObjectPooling && itemPanelPool == null)
        {
            // Auto-create pool if not assigned
            GameObject poolObj = new GameObject("ItemPanelPool");
            poolObj.transform.SetParent(transform);
            itemPanelPool = poolObj.AddComponent<ItemPanelPool>();
            itemPanelPool.itemPanelPrefab = itemPanelPrefab;
        }
    }
    
    void InitializeUI()
    {
        // Initially hide panels
        if (shopMainPanel != null)
            shopMainPanel.SetActive(false);
        if (shopDetailPanel != null)
            shopDetailPanel.SetActive(false);
    }
    
    void SetupEventListeners()
    {
        // Setup category buttons
        for (int i = 0; i < categoryButtons.Length && i < 6; i++)
        {
            int categoryIndex = i; // Capture for closure
            categoryButtons[i].onClick.AddListener(() => OnCategorySelected(categoryIndex));
        }
        
        // Setup detail panel buttons
        if (buyButton != null)
            buyButton.onClick.AddListener(OnBuyItem);
        if (closeDetailButton != null)
            closeDetailButton.onClick.AddListener(CloseDetailPanel);
        
        // Setup main panel close button
        if (closeShopButton != null)
            closeShopButton.onClick.AddListener(CloseShop);
    }
    
    public void OpenShop()
    {
        if (shopMainPanel != null)
        {
            shopMainPanel.SetActive(true);
            RefreshShopDisplay();
        }
    }
    
    public void CloseShop()
    {
        if (shopMainPanel != null)
            shopMainPanel.SetActive(false);
        if (shopDetailPanel != null)
            shopDetailPanel.SetActive(false);
    }
    
    void OnCategorySelected(int categoryIndex)
    {
        if (categoryIndex == currentCategory)
            return;
        
        float startTime = Time.realtimeSinceStartup;
        
        currentCategory = categoryIndex;
        RefreshShopDisplay();
        
        // Update button states
        for (int i = 0; i < categoryButtons.Length; i++)
        {
            if (categoryButtons[i] != null)
            {
                categoryButtons[i].interactable = (i != categoryIndex);
            }
        }
        
        // Log performance
        float switchTime = Time.realtimeSinceStartup - startTime;
        
        Debug.Log($"Category switch to {categoryIndex} completed in {switchTime * 1000f:F2}ms");
    }
    
    public void RefreshShopDisplay()
    {
        // Return all current panels to pool
        ReturnAllPanelsToPool();
        
        if (shopLoader == null || shopLoader.primaryShop == null)
        {
            Debug.LogWarning("ShopLoader or primary shop data not available");
            return;
        }
        
        // Get items for current category
        List<GShopItem> categoryItems = GetItemsForCategory(currentCategory);
        
        // Create item panels using pooling
        foreach (GShopItem item in categoryItems)
        {
            CreateItemPanelFromPool(item);
        }
    }
    
    List<GShopItem> GetItemsForCategory(int categoryIndex)
    {
        List<GShopItem> items = new List<GShopItem>();
        
        if (shopLoader.primaryShop.items == null)
            return items;
        
        foreach (GShopItem item in shopLoader.primaryShop.items)
        {
            if (IsItemInCategory(item, categoryIndex))
            {
                items.Add(item);
            }
        }
        
        return items;
    }
    
    bool IsItemInCategory(GShopItem item, int categoryIndex)
    {
        // Category mapping: 0=1, 1=2, 2=3+4+5, 3=6, 4=7, 5=8
        switch (categoryIndex)
        {
            case 0: return item.mainType == 0; // Category 1
            case 1: return item.mainType == 1; // Category 2
            case 2: return item.mainType >= 2 && item.mainType <= 4; // Categories 3, 4, 5 merged
            case 3: return item.mainType == 5; // Category 6
            case 4: return item.mainType == 6; // Category 7
            case 5: return item.mainType == 7; // Category 8
            default: return false;
        }
    }
    
    void CreateItemPanelFromPool(GShopItem item)
    {
        GameObject itemPanel = null;
        
        if (useObjectPooling && itemPanelPool != null)
        {
            // Get panel from pool
            itemPanel = itemPanelPool.GetPanel();
        }
        else
        {
            // Fallback to instantiate if pooling disabled
            if (itemPanelPrefab != null && itemContainer != null)
            {
                itemPanel = Instantiate(itemPanelPrefab, itemContainer);
            }
        }
        
        if (itemPanel != null && itemContainer != null)
        {
            // Set parent and position
            itemPanel.transform.SetParent(itemContainer);
            itemPanel.transform.localScale = Vector3.one;
            
            // Setup the panel
            ShopItemPanel itemPanelScript = itemPanel.GetComponent<ShopItemPanel>();
            if (itemPanelScript != null)
            {
                itemPanelScript.SetupItem(item, this);
            }
            
            currentItemPanels.Add(itemPanel);
        }
    }
    
    void ReturnAllPanelsToPool()
    {
        if (useObjectPooling && itemPanelPool != null)
        {
            // Return all panels to pool
            foreach (GameObject panel in currentItemPanels)
            {
                if (panel != null)
                {
                    itemPanelPool.ReturnPanel(panel);
                }
            }
        }
        else
        {
            // Destroy panels if not using pooling
            foreach (GameObject panel in currentItemPanels)
            {
                if (panel != null)
                    Destroy(panel);
            }
        }
        
        currentItemPanels.Clear();
    }
    
    public void ShowItemDetail(GShopItem item)
    {
        selectedItem = item;
        Debug.Log($"$ Local ID of selected item: {item.localId}");
        if (shopDetailPanel != null)
        {
            shopDetailPanel.SetActive(true);
            
            // Get the ShopDetailPanel component and call its SetupDetailPanel method
            ShopDetailPanel detailPanelScript = shopDetailPanel.GetComponent<ShopDetailPanel>();
            if (detailPanelScript != null)
            {
                detailPanelScript.SetupDetailPanel(item, this);
            }
            else
            {
                Debug.LogError("ShopDetailPanel script not found on shopDetailPanel GameObject!");
                // Fallback to the old method
                UpdateDetailPanel(item);
            }
        }
    }
    
    void UpdateDetailPanel(GShopItem item)
    {
        if (detailItemName != null)
            detailItemName.text = item.name;
        
        if (detailItemDescription != null)
            detailItemDescription.text = item.desc;
        
        if (detailItemQuantity != null)
            detailItemQuantity.text = $"Quantity: {item.num}";
        
        // Find the best buy option (first non-zero price)
        uint bestPrice = 0;
        for (int i = 0; i < item.buy.Length; i++)
        {
            if (item.buy[i].price > 0)
            {
                bestPrice = item.buy[i].price;
                break;
            }
        }
        
        if (detailItemPrice != null)
            detailItemPrice.text = $"Price: {bestPrice}";
        
        // Load icon based on item name (you'll need to implement icon loading)
        if (detailItemIcon != null)
        {
            LoadItemIcon(detailItemIcon, item.name);
        }
    }
    
    void LoadItemIcon(Image iconImage, string itemName)
    {
        // TODO: Implement icon loading based on item name
        // This is where you'd load the appropriate icon sprite
        // For now, we'll leave it empty for you to implement
        Debug.Log($"Loading icon for item: {itemName}");
    }
    
    void CloseDetailPanel()
    {
        if (shopDetailPanel != null)
            shopDetailPanel.SetActive(false);
    }
    
    void OnBuyItem()
    {
        if (selectedItem.id == 0)
            return;
        
        // TODO: Implement purchase logic
        Debug.Log($"Attempting to buy item: {selectedItem.name} (ID: {selectedItem.id})");
        
        // Close detail panel after purchase attempt
        CloseDetailPanel();
    }
    
    void OnDestroy()
    {
        // Clean up pooled objects
        if (useObjectPooling && itemPanelPool != null)
        {
            itemPanelPool.ReturnAllPanels();
        }
        else
        {
            // Fallback cleanup
            foreach (GameObject panel in currentItemPanels)
            {
                if (panel != null)
                    Destroy(panel);
            }
        }
        
        currentItemPanels.Clear();
    }
}