using UnityEngine;
using System.Linq;
using Animancer;
using BaseGames.Core.Events;
using BaseGames.Input;
using BaseGames.Combat;
using BaseGames.Parry;
using BaseGames.Skills;

namespace BaseGames.Player.States
{
    /// <summary>
    /// 玩家主控制器（协调器）。位于 Player/States/ 程序集，以便引用所有具体状态类型。
    /// 实现 IDamageable + IPoiseSource（架构 06_CombatModule §13）。
    /// 依赖注入：同节点组件由 RequireComponent + Awake 自动获取；跨节点引用通过 [SerializeField] 绑定。
    /// </summary>
    [DefaultExecutionOrder(-100)]
    [RequireComponent(typeof(InputBuffer))]
    [RequireComponent(typeof(PlayerMovement))]
    [RequireComponent(typeof(PlayerStats))]
    [RequireComponent(typeof(AnimancerComponent))]
    public class PlayerController : MonoBehaviour, IDamageable, IPoiseSource
    {
        // ── 同节点组件（由 RequireComponent 保证存在，Awake 中自动获取）─────
        private PlayerMovement    _movement;
        private PlayerStats       _stats;
        private AnimancerComponent _animancer;

        // ── 配置 SO ───────────────────────────────────────────────────────────
        [Header("配置")]
        [SerializeField] private PlayerMovementConfigSO   _movementConfig;
        [SerializeField] private PlayerAnimationConfigSO  _animConfig;
        [SerializeField] private InputReaderSO             _inputReader;
        [SerializeField] private FormConfigSO              _formConfig;

        // ── 战斗组件 ──────────────────────────────────────────────────────────
        [Header("战斗")]
        [SerializeField] private PlayerCombat       _combat;
        [SerializeField] private FormController     _formController;
        [SerializeField] private WeaponManager      _weaponManager;
        [SerializeField] private SkillManager       _skillManager;
        [SerializeField] private SpringSystem       _springSystem;
        [SerializeField] private ParrySystem        _parrySystem;
        [SerializeField] private HurtBox            _hurtBox;
        [SerializeField] private ShieldComponent    _shield;
        [SerializeField] private PlayerWallDetector _wallDetector;

        // ── 事件频道 ──────────────────────────────────────────────────────────
        [Header("事件频道")]
        [SerializeField] private VoidEventChannelSO _onPlayerDied;
        /// <summary>
        /// Start() 时广播玩家 Transform（EnemyBase / ProjectileManager 等订阅此频道）。
        /// 替代每个敌人在 Awake 中独立 FindWithTag 的 O(n) 全场景扫描。
        /// </summary>
        [SerializeField] private TransformEventChannelSO _onPlayerSpawned;
        // ── 运行时 ────────────────────────────────────────────────────────────
        private InputBuffer _inputBuffer;
        private bool _missingDependencyLogged;
        private bool _dependenciesReady;
        /// <summary>
        /// 当前腾空可用的额外跳跃次数（二段跳）。
        /// 由 IdleState/RunState.OnStateEnter 落地时通过 ResetAirJumps() 重置；
        /// JumpState/FallState 判断 HasAbility(DoubleJump) 后消耗。
        /// </summary>
        private int _airJumpsLeft;
#if UNITY_EDITOR
        [Header("调试")]
        [SerializeField] private bool _debugValidateTransitions = true;

        [Header("── 运行时状态 ──")]
        [SerializeField] private string _dbg_CurrentState;
        [SerializeField] private bool   _dbg_IsGrounded;
        [SerializeField] private int    _dbg_AirJumpsLeft;
        [SerializeField] private bool   _dbg_CanDash;
        [SerializeField] private bool   _dbg_IsInvincible;
#endif

        // Overlay Layer（Layer 1）：供 SpringState / SoulSkill 等叠加层动画使用
        // Base Layer（Layer 0）：移动/攻击/受伤/死亡等全身状态动画
        private AnimancerLayer _overlayLayer;

        // ── 状态实例 ──────────────────────────────────────────────────────────
        private PlayerStateBase _currentState;
        private readonly System.Collections.Generic.Dictionary<System.Type, PlayerStateBase> _states = new();

        // ── IDamageable 实现 ──────────────────────────────────────────────────
        public bool IsAlive      => _stats != null && _stats.IsAlive;
        public bool IsInvincible => _stats != null && _stats.IsInvincible;
        public int  Defense      => 0;

        public void TakeDamage(DamageInfo info)
        {
            if (_stats == null) return;
            _stats.TakeDamage(info.FinalDamage);

            // 当前状态标记为无敌（如旧版冲刺状态），或 Stats 层无敌窗口仍激活
            // （冲刺无敌帧 DashInvincibilityDuration 内：跳过受击硬直；窗口过期后可被打断）
            if (_currentState?.IsInvincible == true || (_stats != null && _stats.IsInvincible)) return;

            if (_stats.IsAlive)
            {
                GetState<HurtState>()?.Initialize(info);
                TransitionTo(GetState<HurtState>());
            }
            else
            {
                TransitionTo(GetState<DeadState>());
                _onPlayerDied?.Raise();
            }
        }

        // ── IPoiseSource 实现（架构 06_CombatModule §13）─────────────────────
        /// <summary>
        /// 玩家不拥有霸体，始终返回 <see cref="PoiseLevel.None"/>。
        /// 设计决策：玩家不拥有霸体，始终返回 <see cref="PoiseLevel.None"/>。
        /// 玩家依靠走位和弹反规避伤害而非硬吃，以保持战斗的负担感和张力。
        /// 若未来需要临时霸体（如特定技能动作），请通过独立的覆盖标记实现，
        /// 而非在此处引入状态，以保持接口语义清晰。
        /// </summary>
        public PoiseLevel GetCurrentPoiseLevel() => PoiseLevel.None;

        // ── 公开属性（供状态类访问）──────────────────────────────────────────
        public PlayerMovement          Movement      => _movement;
        public PlayerStats             Stats         => _stats;
        public AnimancerComponent      Animancer     => _animancer;
        public PlayerMovementConfigSO  MovConfig     => _movementConfig;
        public PlayerAnimationConfigSO AnimConfig    => _animConfig;
        public InputReaderSO           Input         => _inputReader;
        public InputBuffer             Buffer        => _inputBuffer;

        public PlayerCombat       Combat        => _combat;
        public FormController     Form          => _formController;
        public WeaponManager      Weapon        => _weaponManager;
        public SkillManager       Skill         => _skillManager;
        public SpringSystem       Spring        => _springSystem;
        public ParrySystem        Parry         => _parrySystem;
        public HurtBox            HurtBox       => _hurtBox;
        public ShieldComponent    Shield        => _shield;
        public PlayerWallDetector WallDetector  => _wallDetector;

        public bool IsGrounded      => _movement != null && _movement.IsGrounded;
        public int  FacingDirection => _movement != null ? _movement.FacingDirection : 1;

        // ── 空中跳跃 API（二段跳）────────────────────────────────────────────
        public int  AirJumpsLeft   => _airJumpsLeft;
        public void UseAirJump()   => _airJumpsLeft = Mathf.Max(0, _airJumpsLeft - 1);
        /// <summary>
        /// 落地时重置空中跳跃次数（由 IdleState/RunState.OnStateEnter 调用）。
        /// 若解锁 DoubleJump 则重置为 MovConfig.MaxAirJumps，否则为 0。
        /// </summary>
        public void ResetAirJumps() =>
            _airJumpsLeft = (_stats != null && _stats.HasAbility(AbilityType.DoubleJump))
                ? (_movementConfig != null ? _movementConfig.MaxAirJumps : 1)
                : 0;

        // ── 抓墙高度记忆 API ──────────────────────────────────────────────────
        // wallGrabY：首次抓住某面墙壁时记录的 Y 坐标；用于防止单面墙无限向上爬。
        // wallGrabDir：当前记录所属墙壁方向（+1=右墙，-1=左墙，0=无）。
        // isPostWallJump：蹬墙跳后未落地标记，允许靠近墙壁时自动抓墙。
        private float _wallGrabY   = float.NegativeInfinity;
        private int   _wallGrabDir = 0;
        private bool  _isPostWallJump;

        public float WallGrabY      => _wallGrabY;
        public int   WallGrabDir    => _wallGrabDir;
        public bool  IsPostWallJump => _isPostWallJump;

        /// <summary>
        /// 进入 WallSlideState 时调用。
        /// 不同墙壁（dir != _wallGrabDir）→ 重置并记录新高度；
        /// 同一面墙壁 → 保留原记录（防止攀爬重置）。
        /// </summary>
        public void RecordWallGrab(int dir, float y)
        {
            if (dir != _wallGrabDir)
            {
                _wallGrabDir = dir;
                _wallGrabY   = y;
            }
            // 同一面墙：保留 _wallGrabY，不更新
        }

        /// <summary>落地时重置抓墙记录（由 IdleState/RunState.OnStateEnter 调用）。</summary>
        public void ResetWallGrab()
        {
            _wallGrabY   = float.NegativeInfinity;
            _wallGrabDir = 0;
        }

        /// <summary>
        /// 设置蹬墙跳后自动抓墙标记。
        /// true：由 WallJumpState.OnStateEnter 设置；
        /// false：由 IdleState/RunState.OnStateEnter（落地）或 WallSlideState.OnStateEnter（已消耗）清除。
        /// </summary>
        public void SetPostWallJump(bool value) => _isPostWallJump = value;

        // ── Overlay Layer API（供 SpringState / SoulSkill 等叠加动画使用）─────
        /// <summary>
        /// 在 Overlay Layer（Layer 1）播放动画，叠加于当前 Base Layer 动画之上。
        /// 适用于灵泉使用、魂技能等需要与移动动画并行的上半身动作。
        /// </summary>
        public AnimancerState PlayOnOverlay(AnimationClip clip)
            => _overlayLayer?.Play(clip);

        /// <summary>停止 Overlay Layer 动画，淡出回 Base Layer。</summary>
        public void StopOverlay(float fadeDuration = 0.1f)
            => _overlayLayer?.StartFade(0f, fadeDuration);

        // ── Unity Lifecycle ───────────────────────────────────────────────────
        private void Awake()
        {
            Debug.Assert(_movementConfig != null, "[PlayerController] _movementConfig 未赋值，请在 Inspector 中指定 PlayerMovementConfigSO。", this);
            ResolveDependencies();

            // 初始化 Animancer 双层动画：Layer 0 = Base（全身状态），Layer 1 = Overlay（叠加层）
            if (_animancer != null)
            {
                // 确保 Layer 1 存在；AnimancerComponent 默认只有 Layer 0
                while (_animancer.Layers.Count <= 1)
                    _animancer.Layers.Add();
                _overlayLayer = _animancer.Layers[1];
            }

            // 注入 HurtBox 依赖
            if (_hurtBox != null)
            {
                if (_shield != null) _hurtBox.SetShieldable(_shield);
                if (_parrySystem != null) _hurtBox.SetParrySystem(_parrySystem);
                _hurtBox.SetPoiseSource(this);
            }

            // 将唯一配置点（_inputReader）注入到 ParrySystem。
            // ParrySystem 不再需要在 Inspector 单独配置 InputReaderSO。
            if (_parrySystem != null)
                _parrySystem.SetInputReader(_inputReader);

            InitializeStates();

            // 订阅 ParrySystem C# 事件
            if (_parrySystem != null)
            {
                _parrySystem.OnParryActivated += OnParryActivated;
                _parrySystem.OnParryConsumed  += OnParryConsumedHandler;
            }

            // 订阅灵泉使用输入
            if (_inputReader != null)
                _inputReader.UseSpringEvent += OnUseSpring;
        }

        private void OnDestroy()
        {
            if (_parrySystem != null)
            {
                _parrySystem.OnParryActivated -= OnParryActivated;
                _parrySystem.OnParryConsumed  -= OnParryConsumedHandler;
            }

            if (_inputReader != null)
                _inputReader.UseSpringEvent -= OnUseSpring;
        }

        /// <summary>弹反输入激活时由 ParrySystem 触发 → 转换到 ParryState。</summary>
        private void OnParryActivated()
        {
            if (_states.ContainsKey(typeof(ParryState)))
                TransitionTo(GetState<ParryState>());
        }

        /// <summary>弹反命中成功时由 ParrySystem 触发 → 发放灵力并恢复护盾。</summary>
        private void OnParryConsumedHandler(BaseGames.Parry.ParryInfo info)
        {
            _stats?.AddSoul(info.SoulGained);
            _shield?.OnParrySuccess();
        }

        /// <summary>灵泉输入：地面且有剩余充能时转入 SpringState 使用一次。</summary>
        private void OnUseSpring()
        {
            if (_stats == null || _stats.CurrentSpringCharges <= 0) return;
            if (_movement != null && !_movement.IsGrounded) return;
            if (_states.ContainsKey(typeof(SpringState)))
                TransitionTo(GetState<SpringState>());
        }

        private void Start()
        {
            if (!HasRequiredStateDependencies())
                return;

            // 广播玩家 Transform：EnemyBase / ProjectileManager 等订阅者将通过事件接收引用
            // （必须在 Start 中调用，确保所有 Awake/OnEnable 订阅已就绪）
            _onPlayerSpawned?.Raise(transform);

            TransitionTo(GetState<IdleState>());
        }

        private void Update()
        {
            if (!HasRequiredStateDependencies())
                return;

            // 冲刺冷却计时
            GetState<DashState>()?.TickCooldown(Time.deltaTime);

            _currentState?.OnStateUpdate();

#if UNITY_EDITOR
            _dbg_CurrentState  = _currentState?.GetType().Name ?? "None";
            _dbg_IsGrounded    = _movement != null && _movement.IsGrounded;
            _dbg_AirJumpsLeft  = _airJumpsLeft;
            _dbg_CanDash       = GetState<DashState>()?.CanDash ?? false;
            _dbg_IsInvincible  = _stats != null && _stats.IsInvincible;
#endif
        }

        private void FixedUpdate()
        {
            _currentState?.OnStateFixedUpdate();
        }

        private void LateUpdate()
        {
            _movement?.UpdateFacing();
        }

        // ── 状态机 ────────────────────────────────────────────────────────────
        public void TransitionTo(PlayerStateBase newState)
        {
#if UNITY_EDITOR
            if (_debugValidateTransitions && _currentState != null && newState != null)
            {
                var allowed = _currentState.ValidTransitions;
                if (allowed.Count > 0 && !allowed.Contains(newState.GetType()))
                    Debug.LogWarning(
                        $"[PlayerController] 非预期转换: {_currentState.GetType().Name} → {newState.GetType().Name}",
                        this);
            }
#endif
            _currentState?.OnStateExit();
            _currentState = newState;
            _currentState?.OnStateEnter();
        }

        private void InitializeStates()
        {
            _states[typeof(IdleState)]       = new IdleState(this);
            _states[typeof(RunState)]        = new RunState(this);
            _states[typeof(JumpState)]       = new JumpState(this);
            _states[typeof(FallState)]       = new FallState(this);
            _states[typeof(AttackState)]     = new AttackState(this);
            _states[typeof(DashState)]       = new DashState(this);
            _states[typeof(WallSlideState)]  = new WallSlideState(this);
            _states[typeof(WallJumpState)]   = new WallJumpState(this);
            _states[typeof(AirAttackState)]  = new AirAttackState(this);
            _states[typeof(DownAttackState)] = new DownAttackState(this);
            _states[typeof(UpAttackState)]   = new UpAttackState(this);
            _states[typeof(HurtState)]       = new HurtState(this);
            _states[typeof(DeadState)]       = new DeadState(this);
            _states[typeof(SpringState)]     = new SpringState(this);
            _states[typeof(ParryState)]      = new ParryState(this);
            _states[typeof(SwimState)]       = new SwimState(this);
        }

        /// <summary>
        /// 按类型获取状态实例。未注册时返回 null（供可选状态调用方安全使用）。
        /// </summary>
        public T GetState<T>() where T : PlayerStateBase
            => _states.TryGetValue(typeof(T), out var s) ? (T)s : null;

        private void ResolveDependencies()
        {
            if (_movement == null)
                _movement = GetComponent<PlayerMovement>();
            if (_stats == null)
                _stats = GetComponent<PlayerStats>();
            if (_animancer == null)
                _animancer = GetComponent<AnimancerComponent>();
            if (_inputBuffer == null)
                _inputBuffer = GetComponent<InputBuffer>();

            // 将唯一配置点（_inputReader）注入到同一 GameObject 上的 InputBuffer。
            // InputBuffer 不再需要在 Inspector 单独配置 InputReaderSO。
            if (_inputBuffer != null)
                _inputBuffer.Init(_inputReader);
        }

        private bool HasRequiredStateDependencies()
        {
            if (_dependenciesReady) return true;

            bool ok = _movement != null && _animancer != null && _inputBuffer != null && _inputReader != null;
            if (ok)
            {
                _dependenciesReady = true;
                _missingDependencyLogged = false;
                return true;
            }

            if (!_missingDependencyLogged)
            {
                Debug.LogError($"[PlayerController] Missing required dependencies. " +
                               $"Movement={(_movement != null ? "OK" : "NULL")}, " +
                               $"Animancer={(_animancer != null ? "OK" : "NULL")}, " +
                               $"InputBuffer={(_inputBuffer != null ? "OK" : "NULL")}, " +
                               $"InputReader={(_inputReader != null ? "OK" : "NULL")}");
                _missingDependencyLogged = true;
            }

            return false;
        }


        // ── 状态访问器 ────────────────────────────────────────────────────────
        // 使用 GetState<T>() 按类型获取任意状态实例，不再暴露具名属性。
    }
}