using System;
using System.Collections.Generic;
using Cielonos.Core.Interaction;
using Cielonos.MainGame.Characters;
using Cielonos.MainGame.Inventory;
using Cielonos.MainGame.Inventory.Collections;
using Cielonos.MainGame.Items;
using Cielonos.MainGame.UI;
using UnityEngine;

namespace Cielonos.MainGame.Interactions
{
    /// <summary>
    /// 物流中心（商店）场景交互对象。
    /// 玩家靠近按交互键后呼出 LogisticCenterUIPage，显示可购买的随机装备。
    /// 商店可反复打开（不像机械台单次使用），商品在首次进入时生成，买完即消失。
    /// 货币通过消耗背包中的 RareMaterial 消耗品来支付。
    /// </summary>
    public class LogisticsCenter : InteractableObjectBase
    {
        private const int OFFER_COUNT = 5;

        private List<ShopOffer> currentOffers;
        private bool isInitialized;

        protected override void InitializeChoices()
        {
            choices.Add(new InteractionChoice("Open Logistic Center", OpenShop));
        }

        /// <summary>
        /// 由 RunManager 或场景加载逻辑调用，预先生成本次商店的商品列表和价格。
        /// 若未调用此方法，交互时会自动从 Resources/Items 中生成。
        /// </summary>
        /// <param name="rng">本局 Run 的随机数生成器。</param
        public void Setup(System.Random rng)
        {
            currentOffers = RollShopOffers(rng);
            isInitialized = true;
        }

        private void OpenShop()
        {
            if (!isInitialized)
            {
                System.Random rng = RunManager.Instance?.currentRun?.randomizer?.Next()
                                    ?? new System.Random();
                currentOffers = RollShopOffers(rng);
                isInitialized = true;
            }

            if (currentOffers == null || currentOffers.Count == 0)
            {
                Debug.LogWarning("[LogisticCenter] 候选池为空，没有可售卖的装备。");
                return;
            }

            var uiPage = PlayerCanvas.MainGamePages.logisticsCenterPage;
            uiPage.SetOffers(currentOffers, HandlePurchase);
            uiPage.Open();
        }

        private void HandlePurchase(int index)
        {
            if (index < 0 || index >= currentOffers.Count) return;

            ShopOffer offer = currentOffers[index];

            // 获取玩家背包中的 RareMaterial
            PlayerInventorySubcontroller inventorySc = MainGameManager.Player.inventorySc;
            RareMaterial rareMaterial = MainGameManager.Player.inventorySc.GetRareMaterial();

            if (rareMaterial == null || rareMaterial.stackAmount < offer.price)
            {
                Debug.Log("[LogisticCenter] RareMaterial 不足，无法购买。");
                return;
            }

            // 扣除 RareMaterial
            rareMaterial.Use(offer.price);
            int remaining = rareMaterial != null ? rareMaterial.stackAmount : 0;

            // 将物品加入背包
            inventorySc.backpackSm.ObtainItem(offer.prefab);

            // 从商品列表中移除已购买的商品
            currentOffers.RemoveAt(index);

            Debug.Log($"[LogisticCenter] 玩家购买了 '{offer.prefab.name}'，花费 {offer.price} RareMaterial，剩余 {remaining}。");
        }

        /// <summary>
        /// 从 Resources/Items 中筛选可售卖的装备并生成 ShopOffer（含随机价格）。
        /// 商店出售所有类型装备（MainWeapon、Support、Passive），但排除 None 稀有度。
        /// </summary>
        private static List<ShopOffer> RollShopOffers(System.Random rng)
        {
            ItemFilter filter = ItemFilter.ByRarity(ItemRarity.None).Not();

            List<GameObject> rolledItems = ItemPoolHelper.Roll(
                OFFER_COUNT, rng, filter,
                "MainWeapon", "SupportEquipment", "PassiveEquipment"
            );

            List<ShopOffer> offers = new List<ShopOffer>(rolledItems.Count);
            foreach (GameObject prefab in rolledItems)
            {
                ItemBase item = prefab.GetComponent<ItemBase>();
                if (item == null || item.contentData == null) continue;

                int price = MainGameManager.Config.RollPrice(item.contentData.itemRarity, rng);
                offers.Add(new ShopOffer(prefab, price));
            }

            return offers;
        }
    }

    /// <summary>
    /// 商店中的单个商品条目：包含物品预制体引用和售价。
    /// </summary>
    [Serializable]
    public class ShopOffer
    {
        public GameObject prefab;
        public int price;

        public ShopOffer(GameObject prefab, int price)
        {
            this.prefab = prefab;
            this.price = price;
        }
    }
}