using System;
using System.Collections.Generic;
using UnityEngine;

namespace BaseGames.Player
{
    /// <summary>
    /// 武器管理器。
    /// 监听 FormController.OnFormChanged，依据当前形态切换 ActiveWeapon。
    /// 支持护符 Override：护符调用 SetOverride() 临时替换特定形态的武器。
    /// 架构 05_PlayerModule §7。
    /// </summary>
    public class WeaponManager : MonoBehaviour
    {
        [SerializeField] private FormController _formController;
        [SerializeField] private WeaponSO       _startingWeapon;    // 无 FormController 时的回退武器

        [Header("HitBox 挂载点")]
        [Tooltip("武器 HitBox Prefab 实例化的父节点，应为 Player 层级下的 [WeaponSocket] 子节点。")]
        [SerializeField] private Transform _weaponSocket;

        public WeaponSO              ActiveWeapon        { get; private set; }
        public WeaponHitBoxInstance  ActiveHitBoxInstance { get; private set; }

        public event Action<WeaponSO> OnWeaponChanged;

        // 护符注入的武器覆盖：Key = FormSO.formId，Value = 替换武器（架构 05 §7）
        private readonly Dictionary<string, WeaponSO> _overrides = new();

        // 对象池：避免每次切换形态时 Instantiate/Destroy（Key = WeaponSO，Value = 已创建实例）
        private readonly Dictionary<WeaponSO, WeaponHitBoxInstance> _hitBoxPool = new();

        private void Awake()
        {
            if (_formController != null && _formController.CurrentForm != null)
                ApplyWeapon(_formController.CurrentForm);
            else if (_startingWeapon != null)
                SetDirectWeapon(_startingWeapon);
        }

        private void OnEnable()
        {
            if (_formController != null)
                _formController.OnFormChanged += HandleFormChanged;
        }

        private void OnDisable()
        {
            if (_formController != null)
                _formController.OnFormChanged -= HandleFormChanged;
        }

        private void Start()
        {
            // 若 FormController 在 Awake 时 CurrentForm 尚未初始化，在 Start 重试
            if (ActiveWeapon == null && _formController != null && _formController.CurrentForm != null)
                ApplyWeapon(_formController.CurrentForm);
            else if (ActiveWeapon == null && _startingWeapon != null)
                SetDirectWeapon(_startingWeapon);
        }

        // ── 内部切换 ───────────────────────────────────────────────────────────

        private void HandleFormChanged() => ApplyWeapon(_formController.CurrentForm);

        private void ApplyWeapon(FormSO form)
        {
            if (form == null) return;
            WeaponSO next = _overrides.TryGetValue(form.formId, out var ov) ? ov : form.defaultWeapon;
            if (next == ActiveWeapon) return;
            SetDirectWeapon(next);
        }

        private void SetDirectWeapon(WeaponSO weapon)
        {
            // 归还旧实例到池（SetActive(false) 会触发 HitBox.OnDisable → Deactivate，自动关闭 Collider2D）
            ActiveHitBoxInstance?.gameObject.SetActive(false);

            ActiveWeapon         = weapon;
            ActiveHitBoxInstance = null;

            if (weapon?.hitBoxPrefab != null && _weaponSocket != null)
            {
                if (!_hitBoxPool.TryGetValue(weapon, out var pooled) || pooled == null)
                {
                    var go = Instantiate(weapon.hitBoxPrefab, _weaponSocket);
                    pooled = go.GetComponent<WeaponHitBoxInstance>();
                    _hitBoxPool[weapon] = pooled;
                }
                pooled.gameObject.SetActive(true);
                ActiveHitBoxInstance = pooled;
            }

            // 通知订阅者（PlayerCombat 取消旧实例事件订阅，订阅新实例）
            OnWeaponChanged?.Invoke(weapon);
        }

        private void OnDestroy()
        {
            foreach (var inst in _hitBoxPool.Values)
                if (inst != null) Destroy(inst.gameObject);
            _hitBoxPool.Clear();
        }

        // ── 护符 Override API（由 WeaponOverrideEffect 调用，架构 05 §7）──────

        /// <summary>为指定形态设置武器覆盖。formId 为空 = 覆盖所有形态。</summary>
        public void SetOverride(string formId, WeaponSO weapon)
        {
            if (string.IsNullOrEmpty(formId))
            {
                if (_formController != null)
                    foreach (var f in _formController.AllForms)
                        _overrides[f.formId] = weapon;
            }
            else
            {
                _overrides[formId] = weapon;
            }
            if (_formController?.CurrentForm != null)
                ApplyWeapon(_formController.CurrentForm);
        }

        /// <summary>移除覆盖，恢复默认武器。formId 为空 = 移除所有形态覆盖。</summary>
        public void ClearOverride(string formId)
        {
            if (string.IsNullOrEmpty(formId))
            {
                _overrides.Clear();
            }
            else
            {
                _overrides.Remove(formId);
            }
            if (_formController?.CurrentForm != null)
                ApplyWeapon(_formController.CurrentForm);
        }
    }
}