using System;
using System.Collections.Generic;
using Cielonos.MainGame.Inventory;
using Cielonos.MainGame.Interactions;
using Cielonos.MainGame.Items;
using Sirenix.OdinInspector;
using SLSUtilities.UI;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace Cielonos.MainGame.UI
{
    /// <summary>
    /// 物流中心（商店）UI 页面。
    /// 左侧为可购买商品列表（Selector），右侧为物品详情面板（ItemDetailPanel）。
    /// 玩家点击列表条目选中商品，点击 Buy 确认购买（消耗 RareMaterial 并获得装备）。
    /// </summary>
    public class LogisticsCenterUIPage : UIPageBase
    {
        [Title("Selectors")]
        public GameObject selectorPrefab;
        public RectTransform selectorContainer;
        public List<LogisticsCenterSelector> selectors = new List<LogisticsCenterSelector>();

        [Title("Detail Panel")]
        public ItemDetailPanel itemDetailPanel;

        [Title("Rare Material Display")]
        public TMP_Text currentRareMaterialText;
        public TMP_Text predictedRareMaterialText;

        [Title("Buttons")] 
        public List<Button> categoryButtons;
        private static readonly ItemFilter[] CategoryFilters =
        {
            ItemFilter.None,
            ItemFilter.ByType(ItemType.MainWeapon),
            ItemFilter.ByType(ItemType.Support),
            ItemFilter.ByType(ItemType.Passive),
            ItemFilter.ByType(ItemType.Consumable)
        };
        
        public Button buyButton;
        public Button closeButton;

        // - 运行时数据 -
        private LogisticsCenterSelector currentSelected;
        private Action<int> onPurchaseCallback;
        private List<ShopOffer> currentOffers;
        private ItemFilter activeFilter;

        
        /// <summary>当前选中的 Selector 索引，-1 表示未选中。</summary>
        public int SelectedIndex => currentSelected != null ? selectors.IndexOf(currentSelected) : -1;

        protected override void Start()
        {
            base.Start();

            if (buyButton != null)
            {
                buyButton.onClick.AddListener(OnBuyClicked);
            }

            if (closeButton != null)
            {
                closeButton.onClick.AddListener(OnCloseClicked);
            }

            // 绑定分类按钮
            if (categoryButtons != null)
            {
                for (int i = 0; i < categoryButtons.Count; i++)
                {
                    if (categoryButtons[i] == null) continue;

                    int index = i;
                    categoryButtons[i].onClick.AddListener(() => OnCategoryClicked(index));
                }
            }
        }

        /// <summary>
        /// 用商品列表填充选择器，并注册购买回调。
        /// 每次调用会清除旧选择器并重新生成。
        /// </summary>
        /// <param name="offers">商品列表，每个商品包含预制体和价格。</param>
        /// <param name="onPurchase">玩家点击 Buy 后的回调，参数为选中的商品在原始列表中的索引。</param>
        public void SetOffers(List<ShopOffer> offers, Action<int> onPurchase)
        {
            onPurchaseCallback = onPurchase;
            currentOffers = offers;

            ClearSelectors();

            if (offers == null) return;

            for (int i = 0; i < offers.Count; i++)
            {
                ShopOffer offer = offers[i];
                if (offer == null || offer.prefab == null) continue;

                ItemBase itemComponent = offer.prefab.GetComponent<ItemBase>();
                if (itemComponent == null)
                {
                    Debug.LogWarning($"[LogisticCenterUIPage] 预制体 '{offer.prefab.name}' 缺少 ItemBase 组件，已跳过。");
                    continue;
                }

                LogisticsCenterSelector selector = CreateSelector();
                selector.Setup(itemComponent, offer.price);
            }

            // 重置选中状态与过滤
            currentSelected = null;
            activeFilter = ItemFilter.None;
            RefreshBuyButton();
            RefreshCurrencyDisplay();

            // 详情面板默认隐藏
            if (itemDetailPanel != null)
            {
                itemDetailPanel.ClearPanel();
            }
        }

        /// <summary>
        /// 由 LogisticCenterSelector 调用，选中指定的选择器。
        /// </summary>
        public void SelectItem(LogisticsCenterSelector selector)
        {
            if (selector == null || !selectors.Contains(selector)) return;

            // 取消上一个选中
            if (currentSelected != null)
            {
                currentSelected.SetSelected(false);
            }

            // 设置新选中
            currentSelected = selector;
            currentSelected.SetSelected(true);

            // 更新详情面板
            if (itemDetailPanel != null)
            {
                itemDetailPanel.SetItem(currentSelected.item);
            }

            // 刷新购买按钮状态与货币预测显示
            RefreshBuyButton();
            RefreshCurrencyDisplay();
        }

        protected override void OnPageOpened()
        {
            RefreshBuyButton();
            RefreshCurrencyDisplay();
        }

        protected override void OnPageClosed()
        {
            currentSelected = null;
            onPurchaseCallback = null;
            currentOffers = null;
        }

        private void OnBuyClicked()
        {
            if (currentSelected == null) return;

            int selectorIndex = SelectedIndex;
            if (selectorIndex < 0) return;

            // 检查 RareMaterial 是否足够
            int playerCurrency = MainGameManager.Player.inventorySc.GetRareMaterialAmount();
            if (playerCurrency < currentSelected.price)
            {
                Debug.Log("[LogisticCenterUIPage] RareMaterial 不足，无法购买。");
                return;
            }

            // 先缓存回调
            Action<int> callback = onPurchaseCallback;

            // 调用购买逻辑（会扣除 RareMaterial 并修改 currentOffers 列表）
            callback?.Invoke(selectorIndex);

            // 移除已购买的选择器
            LogisticsCenterSelector purchasedSelector = currentSelected;
            currentSelected = null;
            selectors.Remove(purchasedSelector);
            Destroy(purchasedSelector.gameObject);

            // 刷新所有选择器的价格颜色和货币显示
            RefreshAllSelectorPrices();
            RefreshBuyButton();
            RefreshCurrencyDisplay();

            // 清空详情面板
            if (itemDetailPanel != null)
            {
                itemDetailPanel.ClearPanel();
            }
        }

        private void OnCloseClicked()
        {
            Close();
        }

        /// <summary>
        /// 分类按钮点击回调，根据索引切换当前过滤类型并刷新可见列表。
        /// </summary>
        private void OnCategoryClicked(int index)
        {
            if (index < 0 || index >= CategoryFilters.Length) return;

            activeFilter = CategoryFilters[index];
            ApplyFilter();
        }

        /// <summary>
        /// 按当前 activeFilter 显示/隐藏选择器。
        /// 若当前选中的商品被隐藏，则取消选中。
        /// </summary>
        private void ApplyFilter()
        {
            bool selectedHidden = false;

            foreach (LogisticsCenterSelector selector in selectors)
            {
                if (selector == null || selector.item == null || selector.item.contentData == null)
                    continue;

                bool visible = activeFilter.Match(selector.item);
                selector.gameObject.SetActive(visible);

                if (!visible && selector == currentSelected)
                {
                    selectedHidden = true;
                }
            }

            // 被过滤掉的选中项需要清除
            if (selectedHidden)
            {
                currentSelected.SetSelected(false);
                currentSelected = null;

                if (itemDetailPanel != null)
                {
                    itemDetailPanel.ClearPanel();
                }
            }

            RefreshBuyButton();
            RefreshCurrencyDisplay();
        }

        private LogisticsCenterSelector CreateSelector()
        {
            if (selectorPrefab == null || selectorContainer == null)
            {
                Debug.LogError("[LogisticCenterUIPage] selectorPrefab 或 selectorContainer 未配置。");
                return null;
            }

            GameObject obj = Instantiate(selectorPrefab, selectorContainer);
            LogisticsCenterSelector selector = obj.GetComponent<LogisticsCenterSelector>();
            if (selector == null)
            {
                Debug.LogError("[LogisticCenterUIPage] selectorPrefab 缺少 LogisticCenterSelector 组件。");
                Destroy(obj);
                return null;
            }

            selectors.Add(selector);
            return selector;
        }

        private void ClearSelectors()
        {
            foreach (LogisticsCenterSelector selector in selectors)
            {
                if (selector != null)
                {
                    Destroy(selector.gameObject);
                }
            }

            selectors.Clear();
            currentSelected = null;
        }

        private void RefreshBuyButton()
        {
            if (buyButton == null) return;

            if (currentSelected == null)
            {
                buyButton.interactable = false;
                return;
            }

            int playerCurrency = MainGameManager.Player.inventorySc.GetRareMaterialAmount();
            bool canAfford = playerCurrency >= currentSelected.price;
            buyButton.interactable = canAfford;
        }

        private void RefreshCurrencyDisplay()
        {
            int rmAmount = MainGameManager.Player.inventorySc.GetRareMaterialAmount();
            currentRareMaterialText.text = "Rare Materials: " + rmAmount.ToString();

            if (currentSelected == null)
            {
                predictedRareMaterialText.text = string.Empty;
                return;
            }

            int predicted = rmAmount - currentSelected.price;
            predictedRareMaterialText.color = predicted >= 0 ? new Color(0.3f, 1f, 0.3f, 1f) : new Color(1f, 0.3f, 0.3f, 1f);
            predictedRareMaterialText.text = "(" + predicted.ToString() + ")";
        }

        private void RefreshAllSelectorPrices()
        {
            foreach (LogisticsCenterSelector selector in selectors)
            {
                if (selector != null)
                {
                    selector.RefreshPriceDisplay();
                }
            }
        }
    }
}