using UnityEngine;
using UnityEngine.SceneManagement;
using BaseGames.Core.Events;
using BaseGames.Core.Save;

namespace BaseGames.Core
{
    /// <summary>
    /// 在 Awake 时（最早执行）向 ServiceLocator 注册所有服务。
    /// 挂载在 Persistent 场景的根 GameObject 上。
    /// </summary>
    [DefaultExecutionOrder(-2000)]
    public class GameServiceRegistrar : MonoBehaviour
    {
        [SerializeField] private DeathRespawnService  _deathRespawnService;
        [SerializeField] private SceneService         _sceneService;
        [SerializeField] private EventChannelRegistry _eventChannelRegistry;
        [SerializeField] private SaveManager          _saveManager;
        /// <summary>
        /// Persistent 场景中唯一保留的主 AudioListener（通常挂在主相机上）。
        /// 在 Inspector 中绑定后可完全跳过 Awake 时的 FindObjectsOfType 全场景扫描。
        /// 未绑定时自动执行运行时扫描。
        /// </summary>
        [SerializeField] private AudioListener _primaryListener;
        private bool _audioListenerFixLogged;

        private void Awake()
        {
            // 若 Inspector 已绑定主 AudioListener，直接使用，跳过全场景扫描
            if (_primaryListener != null)
                DisableDuplicateListenersInCurrentScenes();
            else
                EnsureSingleAudioListener();   // 未绑定时回退：全量扫描并自动缓存
            SceneManager.sceneLoaded += OnSceneLoaded;

            // 注册 NullAudioService 作为兜底；AudioManager.Awake 后会用真实实现覆盖
            ServiceLocator.RegisterIfAbsent<IAudioService>(new NullAudioService());

            if (_deathRespawnService)
                ServiceLocator.Register<IDeathRespawnService>(_deathRespawnService);
            if (_sceneService)
                ServiceLocator.Register<ISceneService>(_sceneService);
            if (_eventChannelRegistry)
                ServiceLocator.Register<IEventChannelRegistry>(_eventChannelRegistry);
            if (_saveManager)
                ServiceLocator.Register<ISaveService>(new SaveServiceAdapter(_saveManager));
        }

        private void OnDestroy()
        {
            SceneManager.sceneLoaded -= OnSceneLoaded;
        }

        private void OnSceneLoaded(Scene scene, LoadSceneMode mode)
        {
            if (_primaryListener != null)
            {
                // 仅扫描新加载场景的根节点，避免 FindObjectsOfType 全场景遍历
                int disabled = 0;
                foreach (var root in scene.GetRootGameObjects())
                foreach (var al in root.GetComponentsInChildren<AudioListener>(true))
                {
                    if (al == _primaryListener || !al.enabled) continue;
                    al.enabled = false;
                    disabled++;
                }
                if (disabled > 0)
                    Debug.LogWarning($"[GameServiceRegistrar] Scene '{scene.name}' 中禁用了 {disabled} 个多余的 AudioListener。");
            }
            else
            {
                // 首次加载时 _primaryListener 可能尚未缓存，回退到全量扫描
                EnsureSingleAudioListener();
            }
        }

        /// <summary>
        /// 当 Inspector 已预绑定 _primaryListener 时，无需全场景扫描。
        /// 仅遍历当前已加载场景的根节点，禁用多余的 AudioListener。
        /// </summary>
        private void DisableDuplicateListenersInCurrentScenes()
        {
            int sceneCount = SceneManager.sceneCount;
            int disabled = 0;
            for (int s = 0; s < sceneCount; s++)
            {
                Scene scene = SceneManager.GetSceneAt(s);
                if (!scene.isLoaded) continue;
                foreach (var root in scene.GetRootGameObjects())
                foreach (var al in root.GetComponentsInChildren<AudioListener>(true))
                {
                    if (al == _primaryListener || !al.enabled) continue;
                    al.enabled = false;
                    disabled++;
                }
            }
            if (disabled > 0 && !_audioListenerFixLogged)
            {
                Debug.LogWarning($"[GameServiceRegistrar] Disabled {disabled} duplicate AudioListener(s). Primary: '{_primaryListener.gameObject.name}'.");
                _audioListenerFixLogged = true;
            }
        }

        private void EnsureSingleAudioListener()
        {
            AudioListener[] listeners = FindObjectsOfType<AudioListener>(true);            AudioListener primary = null;
            int enabledCount = 0;

            for (int i = 0; i < listeners.Length; i++)
            {
                AudioListener listener = listeners[i];
                if (listener == null || !listener.enabled || !listener.gameObject.activeInHierarchy)
                    continue;

                enabledCount++;
                if (primary == null)
                    primary = listener;

                if (listener.gameObject.scene.name == "Persistent")
                    primary = listener;
            }

            if (enabledCount <= 1 || primary == null)
            {
                _primaryListener = primary;   // 缓存（含 enabledCount==1 时的单个监听器）
                return;
            }

            int disabled = 0;
            for (int i = 0; i < listeners.Length; i++)
            {
                AudioListener listener = listeners[i];
                if (listener == null || listener == primary)
                    continue;
                if (!listener.enabled || !listener.gameObject.activeInHierarchy)
                    continue;

                listener.enabled = false;
                disabled++;
            }

            _primaryListener = primary;   // 缓存主监听器

            if (disabled > 0 && !_audioListenerFixLogged)
            {
                Debug.LogWarning($"[GameServiceRegistrar] Found {enabledCount} active AudioListeners. Kept '{primary.gameObject.name}' and disabled {disabled} duplicate listener(s).");
                _audioListenerFixLogged = true;
            }
        }
    }

    /// <summary>
    /// 将 SaveManager 适配为 ISaveService。
    /// 由于 BaseGames.Core.Save 与 BaseGames.Core 存在循环依赖风险，
    /// SaveManager 不直接声明实现 ISaveService；由此 Adapter 桥接，
    /// 保持 Core → Core.Save 的单向依赖方向不变。
    /// </summary>
    internal sealed class SaveServiceAdapter : ISaveService
    {
        private readonly BaseGames.Core.Save.SaveManager _save;

        internal SaveServiceAdapter(BaseGames.Core.Save.SaveManager save) => _save = save;

        // ── I/O 操作 ──────────────────────────────────────────────────────
        public System.Threading.Tasks.Task SaveAsync(int slot)       => _save.SaveAsync(slot);
        public System.Threading.Tasks.Task<bool> LoadAsync(int slot) => _save.LoadAsync(slot);
        public void QuickSave()                                       => _save.QuickSave();
        public void QuickLoad()                                       => _save.QuickLoad();
        public System.Threading.Tasks.Task QuickLoadAsync()          => _save.LoadAsync(BaseGames.Core.Save.SaveManager.QuickSaveSlot);
        public bool HasSave(int slot)                                 => _save.SlotExists(slot);
        public int  ActiveSlot                                        => _save.CurrentSlot;
        public System.Threading.Tasks.Task DeleteSlotAsync(int slot) => _save.DeleteSlotAsync(slot);

        // ── 存档点 ────────────────────────────────────────────────────────
        public string LastCheckpointScene   => _save.LastCheckpointScene;
        public string LastCheckpointSpawnId => _save.LastCheckpointSpawnId;

        // ── 世界状态查询 ──────────────────────────────────────────────────
        public bool IsWorldCollected(string id)       => _save.IsWorldCollected(id);
        public bool IsDoorOpened(string id)           => _save.IsDoorOpened(id);
        public bool IsBossDefeated(string bossId)     => _save.IsBossDefeated(bossId);
        public int  GetPlayerMaxHP()                  => _save.GetPlayerMaxHP();
        public bool IsFirstClear(string challengeId)  => _save.IsFirstClear(challengeId);

        // ── 世界标志 & 事件链 ─────────────────────────────────────────────
        public bool   GetFlag(string flagId)                        => _save.GetFlag(flagId);
        public void   SetFlag(string flagId, bool value)            => _save.SetFlag(flagId, value);
        public System.Collections.Generic.IEnumerable<string> GetCompletedChains() => _save.GetCompletedChains();
        public void   SetChainCompleted(string chainId)             => _save.SetChainCompleted(chainId);
    }
}