using System;
using Cielonos.MainGame.Characters;
using Cielonos.MainGame.Characters.Inventory.Collections;
using UnityEngine;

namespace Cielonos.MainGame
{
    /// <summary>
    /// 战斗房间生命周期状态。
    /// </summary>
    public enum BattleRoomState
    {
        Inactive,   // 未进入任何战斗房间
        Fighting,   // 战斗进行中
        Cleared,    // 全部敌人已清除
    }

    public partial class BattleManager
    {
        /// <summary>
        /// 战斗房间生命周期子模块。
        /// 负责监听敌人死亡事件，在房间清空时触发 OnRoomCleared。
        /// </summary>
        public class BattleRoomSubmodule : SubmoduleBase<BattleManager>
        {
            // ----------------------------------------------------------------
            // 状态
            // ----------------------------------------------------------------

            /// <summary>当前战斗房间的生命周期状态。</summary>
            public BattleRoomState roomState = BattleRoomState.Inactive;

            // ----------------------------------------------------------------
            // 事件
            // ----------------------------------------------------------------

            /// <summary>
            /// 战斗房间内所有敌人清除时触发。
            /// 由外部系统（RunManager、RewardDispatcher 等）监听，执行掉落和阶段切换。
            /// </summary>
            public event Action OnRoomCleared;

            /// <summary>
            /// 单个敌人死亡时触发。参数为死亡的敌人实例，供货币/统计系统使用。
            /// </summary>
            public event Action<CharacterBase> OnEnemyDefeated;

            // ----------------------------------------------------------------
            // 构造
            // ----------------------------------------------------------------

            public BattleRoomSubmodule(BattleManager owner) : base(owner)
            {
            }

            // ----------------------------------------------------------------
            // 公共 API
            // ----------------------------------------------------------------

            /// <summary>
            /// 开始一场战斗房间。绑定敌人移除事件，将状态置为 Fighting。
            /// 应在 ZoneManager 完成敌人生成之后调用。
            /// 若当前敌人列表为空（已被清空或无敌人配置），立即标记 Cleared 并触发 OnRoomCleared。
            /// </summary>
            public void StartRoom()
            {
                // 防御性取消订阅，避免因上一场未正确 Reset 导致重复注册
                owner.enemySm.OnEnemyRemoved -= HandleEnemyRemoved;

                if (owner.enemySm.activeEnemiesList.Count == 0)
                {
                    // 无敌人可战斗，直接标记清空
                    roomState = BattleRoomState.Cleared;
                    Debug.Log("[BattleManager] 战斗房间无敌人，直接标记已清空。");
                    OnRoomCleared?.Invoke();
                    return;
                }

                roomState = BattleRoomState.Fighting;
                owner.enemySm.OnEnemyRemoved += HandleEnemyRemoved;
                Debug.Log($"[BattleManager] 战斗房间开始，当前敌人数：{owner.enemySm.activeEnemiesList.Count}");
            }

            /// <summary>
            /// 手动结束/重置战斗房间（场景切换或放弃时调用）。
            /// 解绑事件并重置状态，不触发 OnRoomCleared。
            /// </summary>
            public void Reset()
            {
                owner.enemySm.OnEnemyRemoved -= HandleEnemyRemoved;
                owner.enemySm.Reset();
                roomState = BattleRoomState.Inactive;
                Debug.Log("[BattleManager] 战斗房间已重置。");
            }

            // ----------------------------------------------------------------
            // 内部实现
            // ----------------------------------------------------------------

            /// <summary>监听 EnemySubmodule.OnEnemyRemoved，判断房间是否清空。</summary>
            private void HandleEnemyRemoved(CharacterBase enemy)
            {
                if (roomState != BattleRoomState.Fighting) return;

                OnEnemyDefeated?.Invoke(enemy);
                GrantCurrencyDrop(enemy);
                Debug.Log($"[BattleManager] 敌人死亡：{enemy.name}，剩余：{owner.enemySm.activeEnemiesList.Count}");

                if (owner.enemySm.activeEnemiesList.Count > 0)
                {
                    return;
                }

                // 所有敌人已清除
                roomState = BattleRoomState.Cleared;
                owner.enemySm.OnEnemyRemoved -= HandleEnemyRemoved;
                Debug.Log("[BattleManager] 战斗房间已清空，触发 OnRoomCleared。");
                OnRoomCleared?.Invoke();
            }

            /// <summary>
            /// 根据死亡敌人的 EnemyRank 向玩家发放对应数量的稀有材料。
            /// </summary>
            private void GrantCurrencyDrop(CharacterBase enemy)
            {
                if (enemy is not Enemy typedEnemy) return;
                
                System.Random rng = new System.Random();
                int amount = MainGameManager.Config.RollCurrency(typedEnemy.enemyRank, rng);

                MainGameManager.Player.inventorySc.backpackSm.ObtainItem<RareMaterial>(amount);
                Debug.Log($"[BattleRoomSubmodule] 击杀 {typedEnemy.enemyRank} 敌人，获得稀有材料 x{amount}。");
            }
        }
    }
}