using System;
using System.Collections.Generic;
using Cielonos.Core.Interaction;
using Cielonos.MainGame.Inventory;
using Cielonos.MainGame.Items;
using Cielonos.MainGame.UI;
using Lean.Pool;
using Sirenix.OdinInspector;
using SLSUtilities.General;
using UnityEngine;

namespace Cielonos.MainGame.Interactions
{
    /// <summary>
    /// 机械台（Roguelite 宝箱房）场景交互对象。
    /// 生成时根据配置的权重随机决定稀有度，并实例化对应的 table 模型。
    /// 玩家交互后呼出 MechanicalTableUIPage，显示该稀有度下的随机装备供选择。
    /// 选择后获得装备，标记为 Exhausted（单次使用），不可再次触发。
    /// </summary>
    public class MechanicalTable : InteractableObjectBase
    {
        private const int OFFER_COUNT = 3;

        [TitleGroup("稀有度配置")]
        [Tooltip("每种稀有度对应的 table 模型。生成时，根据稀有度生成对应模型。")]
        [SerializeField]
        private Dictionary<ItemRarity, GameObject> _tablePrefabs = new Dictionary<ItemRarity, GameObject>();
        [SerializeField]
        [Tooltip("当机械台不可用时显示的模型（如已被使用）。")]
        private GameObject _notAvailableTablePrefab;
        private GameObject _currentTable;
        
        [TitleGroup("运行时状态"), ReadOnly]
        public ItemRarity rarity;
        private Dictionary<ItemRarity, float> RarityWeights => MainGameManager.Config.mechanicalTableRarityWeights;
        private List<GameObject> _currentOffers;
        [ShowInInspector]
        private bool _isAvailable;

        private void Start()
        {
            if (!_isAvailable)
            {
                Setup(new System.Random());
            }
        }

        protected override void InitializeChoices()
        {
            choices.Add(new InteractionChoice("Open Mechanical Table", OpenTable));
        }

        /// <summary>
        /// 由 RunManager 或场景加载逻辑调用，预先配置本机械台的稀有度和物品列表。
        /// 使用节点坐标派生的 RNG 确保同 seed 可复现。
        /// </summary>
        /// <param name="rng">本节点的随机数生成器。</param>
        public void Setup(System.Random rng)
        {
            rarity = RollRarity(rng);

            if (_currentTable != null) Destroy(_currentTable);

            if (_tablePrefabs.TryGetValue(rarity, out GameObject tablePrefab) && tablePrefab != null)
            {
                _currentTable = Instantiate(tablePrefab, transform);
            }
            else
            {
                Debug.LogWarning($"[MechanicalTable] 稀有度 {rarity} 没有对应的 table 预制体。");
            }

            _currentOffers = RollItems(rng, rarity);
            _isAvailable = true;
        }

        private void OpenTable()
        {
            // 如果未通过 Setup() 预配置，自动配置（fallback）
            if (!_isAvailable && (_currentOffers == null || _currentOffers.Count == 0))
            {
                System.Random fallbackRng = RunManager.Instance?.currentRun?.randomizer?.Next() ?? new System.Random();
                Setup(fallbackRng);
            }

            if (!_isAvailable) return;

            if (_currentOffers == null || _currentOffers.Count == 0)
            {
                Debug.LogWarning("[MechanicalTable] 候选池为空，没有符合条件的装备。");
                return;
            }

            var uiPage = PlayerCanvas.MainGamePages.mechanicalTablePage;
            uiPage.SetOffers(_currentOffers, HandleOfferSelected);
            uiPage.Open();
        }

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

            GameObject selectedPrefab = _currentOffers[index];

            // 通过 BackpackSubmodule 将物品加入背包
            MainGameManager.Player.inventorySc.backpackSm.ObtainItem(selectedPrefab);

            _isAvailable = false;
            
            Destroy(_currentTable);
            _currentTable = Instantiate(_notAvailableTablePrefab, transform);

            // 禁用场景中的交互触发器
            SetInteractable(false);

            Debug.Log($"[MechanicalTable] 玩家选择了 '{selectedPrefab.name}'（{rarity}），机械台已用完。");
        }

        // ================================================================
        // 稀有度逻辑
        // ================================================================

        /// <summary>
        /// 根据权重表随机选取一个稀有度。
        /// </summary>
        private ItemRarity RollRarity(System.Random rng)
        {
            float totalWeight = 0f;
            foreach (var kvp in RarityWeights)
            {
                totalWeight += kvp.Value;
            }

            if (totalWeight <= 0f)
            {
                Debug.LogWarning("[MechanicalTable] 稀有度权重总和为 0，使用默认 Tera。");
                return ItemRarity.Tera;
            }

            float roll = (float)(rng.NextDouble() * totalWeight);
            float cumulative = 0f;

            foreach (var kvp in RarityWeights)
            {
                cumulative += kvp.Value;
                if (roll <= cumulative)
                {
                    return kvp.Key;
                }
            }

            // 安全回退
            return ItemRarity.Tera;
        }

        /// <summary>
        /// 从 Resources/Items 中按稀有度筛选并加权随机抽取装备。
        /// 机械台只出 Support 和 Passive 类型。
        /// </summary>
        private List<GameObject> RollItems(System.Random rng, ItemRarity targetRarity)
        {
            ItemFilter filter = ItemFilter.ByRarity(targetRarity);

            return ItemPoolHelper.Roll(OFFER_COUNT, rng, filter, "SupportEquipment", "PassiveEquipment");
        }
    }
}