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

public class ShopUIManager : MonoBehaviour
{
    [Header("Shop Data")]
    public GShopLoader shopLoader;

    [Header("UI Panels")]
    public GameObject shopMainPanel;
    public GameObject shopDetailPanel;
    public GameObject subTypeShopPanel;
    [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;
    public ScrollRect detailScrollRect;

    [Header("Main Panel Components")]
    public Button closeShopButton;

    [Header("Cash UI (assign any text fields to mirror cash amount)")]
    [SerializeField] private List<UnityEngine.UI.Text> cashTextsLegacy = new List<UnityEngine.UI.Text>();
    [SerializeField] private List<TMPro.TextMeshProUGUI> cashTextsTMP = new List<TMPro.TextMeshProUGUI>();

    // Keep last known cash so newly opened shops can render immediately.
    private static bool s_hasPendingCash;
    private static int s_pendingCashAmount;

    private List<GameObject> currentItemPanels = new List<GameObject>();
    private GShopItem selectedItem;
    private int currentCategory = 0; // 0-5 for the 6 merged categories
    [Header("Sub Type Shop")]
    //-1 means all sub types
    public SubTypeShop subTypeShop;
    private int currentSubType = -1;
    private bool _shopLoaderEventsSubscribed;

    void Start()
    {
        InitializeUI();
        SetupEventListeners();
        InitializePool();
        SubscribeShopLoaderEvents();
    }

    void SubscribeShopLoaderEvents()
    {
        if (_shopLoaderEventsSubscribed)
            return;
        if (shopLoader == null)
            shopLoader = FindFirstObjectByType<GShopLoader>();
        if (shopLoader == null)
            return;

        shopLoader.OnPrimaryShopLoaded += OnPrimaryShopDataReady;
        _shopLoaderEventsSubscribed = true;

        // Load may have finished before we subscribed (e.g. script order).
        if (shopLoader.IsPrimaryShopLoaded)
            OnPrimaryShopDataReady();
    }

    void OnPrimaryShopDataReady()
    {
        if (shopMainPanel != null && shopMainPanel.activeSelf)
            RefreshShopDisplay();
    }

    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);
        if (subTypeShop != null)
            subTypeShopPanel.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)
        {
            SubscribeShopLoaderEvents();
            shopMainPanel.SetActive(true);
            // Always apply category 0 when opening; OnCategorySelected(0) no-ops if currentCategory is already 0.
            OnCategorySelected(0, forceRefresh: true);
            ApplyPendingCash();
            UnityGameSession.RequesrQueryPlayerCash();
        }
    }

    public void UpdateCash(int amount)
    {
        string text = amount.ToString();
        int major = amount / 100;  // e.g. 49780 -> 497 (KNB)
        int minor = amount % 100; // e.g. 49780 -> 80 (NNB)
        string textMajor = major.ToString();
        string textMinor = minor.ToString();

        // For now only show the first part (major = 497)
        if (cashTextsLegacy != null)
        {
            for (int i = 0; i < cashTextsLegacy.Count; i++)
            {
                var t = cashTextsLegacy[i];
                if (t != null) t.text = text;
                if (t != null) t.text = textMajor;
            }
        }
        if (cashTextsTMP != null)
            for (int i = 0; i < cashTextsTMP.Count; i++)
            {
                var t = cashTextsTMP[i];
                if (t != null) t.text = text;
                if (t != null) t.text = textMajor;
            }
    }

    public static void CacheCash(int amount)
    {
        s_pendingCashAmount = amount;
        s_hasPendingCash = true;

        var all = Resources.FindObjectsOfTypeAll<ShopUIManager>();
        if (all != null)
        {
            for (int i = 0; i < all.Length; i++)
            {
                var ui = all[i];
                if (ui != null && ui.gameObject.scene.IsValid())
                {
                    ui.ApplyPendingCash();
                }
            }
        }
    }

    private void ApplyPendingCash()
    {
        if (s_hasPendingCash)
        {
            UpdateCash(s_pendingCashAmount);
        }
    }
    
    public void CloseShop()
    {
        if (shopMainPanel != null)
            shopMainPanel.SetActive(false);
        if (shopDetailPanel != null)
            shopDetailPanel.SetActive(false);
    }
    
    void OnCategorySelected(int categoryIndex, bool forceRefresh = false)
    {
        if (!forceRefresh && 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");
    }
    
    // Allow external components (e.g., ShopCategoryManager) to switch category
    public void SetCategoryIndex(int categoryIndex)
    {
        OnCategorySelected(categoryIndex);
    }
    
    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
        int siblingIndexCounter = 0;
        foreach (GShopItem item in categoryItems)
        {
            CreateItemPanelFromPool(item, siblingIndexCounter);
            siblingIndexCounter++;
        }

        List<string> subTypeNames = GetSubTypeNamesForCategory(currentCategory);
        currentSubType = -1;
        subTypeShopPanel.SetActive(subTypeNames.Count > 0);
        if (subTypeShop != null)
            subTypeShop.GenerateSubTypeShop(subTypeNames, this);
        


    }

    public void SetSubTypeFilter(int subTypeIndex)
    {
        currentSubType = subTypeIndex;
        ApplySubTypeFilter();
    }
    
    public void SetSubTypeFilterByName(string subTypeName)
    {
        int subTypeIndex = GetSubTypeIndexFromName(subTypeName);
        SetSubTypeFilter(subTypeIndex);
    }
    
    public void ApplySubTypeFilter()
    {
        ReturnAllPanelsToPool();

        if (shopLoader == null || shopLoader.primaryShop == null)
        {
            Debug.LogWarning("ShopLoader or primary shop data not available");
            return;
        }
        if(currentSubType == -1)
        {
            RefreshShopDisplay();
            return;
        }
        List<GShopItem> categoryItems = GetItemsForCategory(currentCategory, currentSubType);
        int siblingIndexCounter = 0;
        foreach (GShopItem item in categoryItems)
        {
            CreateItemPanelFromPool(item, siblingIndexCounter);
            siblingIndexCounter++;
        }
    }
    List<GShopItem> GetItemsForCategory(int categoryIndex, int subTypeIndex=-1)
    {
        List<GShopItem> items = new List<GShopItem>();
        
        if (shopLoader.primaryShop.items == null)
            return items;
        
        foreach (GShopItem item in shopLoader.primaryShop.items)
        {
            if (IsItemInCategory(item, categoryIndex))
            {
                if(IsItemInSubType(item, subTypeIndex))
                {
                    items.Add(item);
                }
            }
        }
        
        return items;
    }
    List<string> GetSubTypeNamesForCategory(int categoryIndex)
    {
        List<string> subTypeNames = new List<string>();
        
        if (shopLoader?.primaryShop?.mainTypes == null)
            return subTypeNames;
        
        // Use the same mapping as IsItemInCategory: 0=0, 1=2, 2=5, 3=1+3+4, 4=6, 5=7
        List<int> mainTypeIndices = new List<int>();
        switch (categoryIndex)
        {
            case 0: mainTypeIndices.Add(0); break;
            case 1: mainTypeIndices.Add(2); break;
            case 2: mainTypeIndices.Add(5); break;
            case 3: mainTypeIndices.Add(1); mainTypeIndices.Add(3); mainTypeIndices.Add(4); break;
            case 4: mainTypeIndices.Add(6); break;
            case 5: mainTypeIndices.Add(7); break;
            default: break;
        }
        
        foreach (int mainTypeIndex in mainTypeIndices)
        {
            if (mainTypeIndex >= 0 && mainTypeIndex < shopLoader.primaryShop.mainTypes.Count)
            {
                foreach (string subType in shopLoader.primaryShop.mainTypes[mainTypeIndex].subTypes)
                {
                    if (!subTypeNames.Contains(subType))
                    {
                        subTypeNames.Add(subType);
                    }
                }
            }
        }
        
        return subTypeNames;
    }
    bool IsItemInCategory(GShopItem item, int categoryIndex)
    {
        // Category mapping: 0=1, 1=2, 2=1+3+4, 3=6, 4=7, 5=8
        switch (categoryIndex)
        {
            case 0: return item.mainType == 0; // Category 1
            case 1: return item.mainType == 2; // Category 2
            case 2: return item.mainType == 5; // Categories 1, 3, 4 merged
            case 3: return item.mainType == 1 || item.mainType == 3 || item.mainType == 4; // Category 6
            case 4: return item.mainType == 6; // Category 7
            case 5: return item.mainType == 7; // Category 8
            default: return false;
        }
    }
    bool IsItemInSubType(GShopItem item, int combinedSubTypeIndex)
    {
        if(combinedSubTypeIndex == -1)
            return true;
        
        // Get the subType name for this item's mainType and subType index
        if (shopLoader?.primaryShop?.mainTypes == null)
            return false;
        
        if (item.mainType < 0 || item.mainType >= shopLoader.primaryShop.mainTypes.Count)
            return false;
        
        var mainType = shopLoader.primaryShop.mainTypes[item.mainType];
        if (item.subType < 0 || item.subType >= mainType.subTypes.Count)
            return false;
        
        string itemSubTypeName = mainType.subTypes[item.subType];
        
        // Get the subType name for the filter index
        string filterSubTypeName = GetSubTypeNameFromIndex(combinedSubTypeIndex);
        
        return itemSubTypeName == filterSubTypeName;
    }
    
    int GetSubTypeIndexFromName(string subTypeName)
    {
        if (shopLoader?.primaryShop?.mainTypes == null || string.IsNullOrEmpty(subTypeName))
            return -1;
        
        // Find the subType name in the current category's mainTypes
        List<int> mainTypeIndices = new List<int>();
        switch (currentCategory)
        {
            case 0: mainTypeIndices.Add(0); break;
            case 1: mainTypeIndices.Add(2); break;
            case 2: mainTypeIndices.Add(5); break;
            case 3: mainTypeIndices.Add(1); mainTypeIndices.Add(3); mainTypeIndices.Add(4); break;
            case 4: mainTypeIndices.Add(6); break;
            case 5: mainTypeIndices.Add(7); break;
            default: break;
        }
        
        // Find the first matching subType across all relevant mainTypes
        // We use a combined index: mainTypeIndex * 1000 + subTypeIndex
        // This allows us to uniquely identify subTypes across different mainTypes
        foreach (int mainTypeIndex in mainTypeIndices)
        {
            if (mainTypeIndex >= 0 && mainTypeIndex < shopLoader.primaryShop.mainTypes.Count)
            {
                var mainType = shopLoader.primaryShop.mainTypes[mainTypeIndex];
                for (int i = 0; i < mainType.subTypes.Count; i++)
                {
                    if (mainType.subTypes[i] == subTypeName)
                    {
                        // Return a combined index: mainTypeIndex * 1000 + subTypeIndex
                        return mainTypeIndex * 1000 + i;
                    }
                }
            }
        }
        
        return -1;
    }
    
    string GetSubTypeNameFromIndex(int combinedIndex)
    {
        if (combinedIndex < 0 || shopLoader?.primaryShop?.mainTypes == null)
            return null;
        
        int mainTypeIndex = combinedIndex / 1000;
        int subTypeIndex = combinedIndex % 1000;
        
        if (mainTypeIndex >= 0 && mainTypeIndex < shopLoader.primaryShop.mainTypes.Count)
        {
            var mainType = shopLoader.primaryShop.mainTypes[mainTypeIndex];
            if (subTypeIndex >= 0 && subTypeIndex < mainType.subTypes.Count)
            {
                return mainType.subTypes[subTypeIndex];
            }
        }
        
        return null;
    }
    void CreateItemPanelFromPool(GShopItem item, int targetSiblingIndex)
    {
        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, false);
            itemPanel.transform.localScale = Vector3.one;
            // Ensure deterministic ordering regardless of pool retrieval order
            itemPanel.transform.SetSiblingIndex(targetSiblingIndex);
            
            // 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);
                detailScrollRect.verticalNormalizedPosition = 1f;
                LayoutRebuilder.ForceRebuildLayoutImmediate(detailScrollRect.content);
            }
        }
    }
    
    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 = $"Price: {bestPrice}";
        Debug.Log($"Detail item price: {detailItemPrice.text}, detail item price != null: {detailItemPrice != null}");
        // 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()
    {
        if (shopLoader != null && _shopLoaderEventsSubscribed)
            shopLoader.OnPrimaryShopLoaded -= OnPrimaryShopDataReady;

        // 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();
    }
}