using BaseGames.Core.Events;
using BaseGames.Feedback;
using UnityEngine;

namespace BaseGames.World
{
    /// <summary>
    /// 单向触发机关。支持玩家按键/玩家接触/攻击三种触发方式。
    /// 通过 VoidEventChannelSO 零耦合激活/停用目标（门/升降台/灯光等）。
    /// _isOneShot = true 时激活状态持久化到 WorldStateRegistry。
    /// </summary>
    [RequireComponent(typeof(Collider2D))]
    public class DirectionalInteractable : MonoBehaviour, IInteractable
    {
        public enum TriggerSide      { Left, Right, Top, Any }
        public enum TriggerCondition { PlayerAttack, PlayerBody, InteractKey }

        [Header("触发条件")]
        [SerializeField] private TriggerSide      _triggerSide      = TriggerSide.Any;
        [SerializeField] private TriggerCondition _triggerCondition = TriggerCondition.InteractKey;

        [Header("行为")]
        [SerializeField] private bool   _isOneShot;
        [SerializeField] private string _interactableId;

        [Header("事件频道")]
        [SerializeField] private VoidEventChannelSO _activationChannel;
        [SerializeField] private VoidEventChannelSO _deactivationChannel;

        [Header("反馈")]
        [SerializeField] private SceneFeedback _activateFeedback;

        [Header("持久化")]
        [SerializeField] private WorldStateRegistry _worldState;

        private bool _activated;

        // ── IInteractable ─────────────────────────────────────────────────────
        public bool   CanInteract    => !(_isOneShot && _activated);
        public string InteractPrompt => _activated ? "已激活" : "交互";

        public void Interact(Transform player)
        {
            if (_triggerCondition != TriggerCondition.InteractKey) return;
            if (!CheckSide(player.position)) return;
            TryActivate();
        }

        public void OnPlayerEnterRange(Transform player) { }
        public void OnPlayerExitRange() { }

        // ── Physics Triggers ──────────────────────────────────────────────────

        /// <summary>
        /// 判断碰撞体是否为有效触发来源。子类可覆写以扩展触发主体（如幻影身体）。
        /// </summary>
        protected virtual bool IsValidTriggerBody(Collider2D col) => col.CompareTag("Player");

        private void OnTriggerEnter2D(Collider2D other)
        {
            if (_triggerCondition != TriggerCondition.PlayerBody) return;
            if (!IsValidTriggerBody(other)) return;
            if (!CheckSide(other.transform.position)) return;
            TryActivate();
        }

        private void OnTriggerExit2D(Collider2D other)
        {
            if (_triggerCondition != TriggerCondition.PlayerBody) return;
            if (!IsValidTriggerBody(other) || _isOneShot) return;
            _activated = false;
            _deactivationChannel?.Raise();
        }

        // ── Damage-based Trigger（由 HurtBox/TileDamageReceiver 调用）────────

        public void TryInteractFromDamage(BaseGames.Combat.DamageInfo info)
        {
            if (_triggerCondition != TriggerCondition.PlayerAttack) return;
            if (!CheckSide(info.SourcePosition)) return;
            TryActivate();
        }

        // ── Core ──────────────────────────────────────────────────────────────

        protected void TryActivate()
        {
            if (_isOneShot && _activated) return;

            _activated = true;
            _activateFeedback?.Play();
            _activationChannel?.Raise();

            if (_isOneShot && !string.IsNullOrEmpty(_interactableId))
                _worldState?.SetFlag("mechanism_" + _interactableId);
        }

        private bool CheckSide(Vector2 sourcePos)
        {
            if (_triggerSide == TriggerSide.Any) return true;

            var dir = (sourcePos - (Vector2)transform.position).normalized;
            return _triggerSide switch
            {
                TriggerSide.Left  => dir.x < -0.4f,
                TriggerSide.Right => dir.x >  0.4f,
                TriggerSide.Top   => dir.y >  0.4f,
                _                 => true
            };
        }

        private void Start()
        {
            // 读档恢复：仅标记 _activated = true，不广播激活事件。
            // 下游组件（PuzzleReceiver / 动画门等）已通过各自的 WorldStateRegistry 检查在 Start 中自行恢复，
            // 重复广播会导致它们再次播放开门动画等副作用。
            if (_isOneShot && !string.IsNullOrEmpty(_interactableId)
                && _worldState != null
                && _worldState.HasFlag("mechanism_" + _interactableId))
            {
                _activated = true;
            }
        }
    }
}