// Assets/Scripts/World/Puzzle/PuzzleSwitch.cs
using System;
using Animancer;
using BaseGames.Feedback;
using BaseGames.Input;
using BaseGames.World;
using UnityEngine;

namespace BaseGames.Puzzle
{
    public enum SwitchTriggerMode
    {
        InteractOnce,   // 玩家交互一次，永久激活
        InteractToggle, // 玩家交互切换开关
        Pressure,       // 踩上激活，离开停用
        Hold,           // 按住交互键持续激活
    }

    /// <summary>
    /// 通用谜题开关，支持三种触发模式。
    /// 实现 ISwitchable + IInteractable（玩家手动触发）。
    /// </summary>
    [RequireComponent(typeof(Collider2D))]
    public class PuzzleSwitch : MonoBehaviour, ISwitchable, IInteractable
    {
        [Header("触发模式")]
        [SerializeField] private SwitchTriggerMode  _mode        = SwitchTriggerMode.InteractOnce;

        [Header("状态")]
        [SerializeField] private bool               _startsActive = false;
        [SerializeField] private string             _switchId;              // 持久化唯一 ID（空串则不持久化）

        [Header("视觉")]
        [SerializeField] private AnimancerComponent _animancer;
        [SerializeField] private AnimationClip      _activeClip;
        [SerializeField] private AnimationClip      _inactiveClip;
        [SerializeField] private SceneFeedback        _activateFeedback;

        [Header("持久化（SO 注入，非 Instance 单例）")]
        [SerializeField] private WorldStateRegistry _worldState;

        [Header("Hold 模式输入（SwitchTriggerMode.Hold 时必填）")]
        [SerializeField] private InputReaderSO _inputReader;

        private bool _isActive;

        public bool IsActive => _isActive;
        public event Action<bool> OnStateChanged;

        private void Awake()
        {
            bool savedState = !string.IsNullOrEmpty(_switchId)
                              && _worldState != null
                              && _worldState.HasFlag("switch_" + _switchId);
            _isActive = savedState || _startsActive;
        }

        private void Start()
        {
            if (_isActive && _activeClip != null) _animancer?.Play(_activeClip);
            else if (_inactiveClip != null)       _animancer?.Play(_inactiveClip);
        }

        // ── IInteractable ────────────────────────────────────────────────────
        public string InteractPrompt => _mode == SwitchTriggerMode.Hold ? "按住交互" : "交互";

        /// <summary>
        /// 压板模式不需要交互提示（物理触发）；InteractOnce 已激活后隐藏提示。
        /// </summary>
        public bool CanInteract => _mode switch
        {
            SwitchTriggerMode.InteractOnce   => !_isActive,
            SwitchTriggerMode.InteractToggle => true,
            SwitchTriggerMode.Hold           => true,
            SwitchTriggerMode.Pressure       => false,
            _                                => false,
        };

        public void Interact(Transform player)
        {
            // Hold 模式通过 OnPlayerEnterRange 订阅输入事件处理，此处不响应
            if (_mode == SwitchTriggerMode.Hold) return;
            if (_mode == SwitchTriggerMode.InteractOnce && _isActive) return;
            SetState(!_isActive);
        }

        public void OnPlayerEnterRange(Transform player)
        {
            if (_mode != SwitchTriggerMode.Hold || _inputReader == null) return;
            _inputReader.InteractEvent          += OnHoldStarted;
            _inputReader.InteractCancelledEvent += OnHoldCancelled;
        }

        public void OnPlayerExitRange()
        {
            UnsubscribeHold();
            // 玩家离开范围时停用 Hold 开关
            if (_mode == SwitchTriggerMode.Hold && _isActive)
                SetState(false);
        }

        // ── ISwitchable ──────────────────────────────────────────────────────
        public void ForceState(bool active) => SetState(active);

        // ── 压板模式 ──────────────────────────────────────────────────────────
        private void OnTriggerEnter2D(Collider2D col)
        {
            if (_mode != SwitchTriggerMode.Pressure) return;
            if (col.CompareTag("Player") || col.CompareTag("PushBox"))
                SetState(true);
        }

        private void OnTriggerExit2D(Collider2D col)
        {
            if (_mode != SwitchTriggerMode.Pressure) return;
            if (col.CompareTag("Player") || col.CompareTag("PushBox"))
                SetState(false);
        }

        private void SetState(bool active)
        {
            if (_isActive == active) return;
            _isActive = active;

            if (active) _animancer?.Play(_activeClip);
            else        _animancer?.Play(_inactiveClip);

            _activateFeedback?.Play();
            OnStateChanged?.Invoke(active);

            // 持久化到 WorldStateRegistry（激活添加标记；停用清除标记）
            if (!string.IsNullOrEmpty(_switchId))
            {
                if (active) _worldState?.SetFlag("switch_" + _switchId);
                else        _worldState?.ClearFlag("switch_" + _switchId);
            }
        }

        // ── Hold 模式辅助 ──────────────────────────────────────────────────────

        private void OnHoldStarted()   => SetState(true);
        private void OnHoldCancelled() => SetState(false);

        private void UnsubscribeHold()
        {
            if (_inputReader == null) return;
            _inputReader.InteractEvent          -= OnHoldStarted;
            _inputReader.InteractCancelledEvent -= OnHoldCancelled;
        }

        private void OnDestroy() => UnsubscribeHold();
    }
}