using System.Collections.Generic;
using UnityEngine;

namespace BaseGames.Enemies.Abilities
{
    /// <summary>
    /// 能力注册表（架构 07_EnemyModule §8.3）。
    /// EnemyBase.Awake 时调用 <see cref="CollectFrom"/> 自动扫描子物体上所有
    /// <see cref="EnemyAbilityBase"/> 组件，按 abilityId 建立 O(1) 查询字典。
    /// </summary>
    public sealed class EnemyAbilityRegistry
    {
        private readonly Dictionary<string, EnemyAbilityBase> _byId
            = new Dictionary<string, EnemyAbilityBase>(8);
        private readonly List<EnemyAbilityBase> _all = new List<EnemyAbilityBase>(8);

        /// <summary>所有已注册能力（只读）。</summary>
        public IReadOnlyList<EnemyAbilityBase> All => _all;

        public void CollectFrom(GameObject root)
        {
            _byId.Clear();
            _all.Clear();
            root.GetComponentsInChildren(true, _all);
            for (int i = 0; i < _all.Count; i++)
            {
                var ab = _all[i];
                if (ab == null || ab.Config == null || string.IsNullOrEmpty(ab.Config.abilityId))
                    continue;
                if (_byId.ContainsKey(ab.Config.abilityId))
                {
                    Debug.LogError($"[EnemyAbilityRegistry] 重复 abilityId='{ab.Config.abilityId}' 于 {ab.gameObject.name}，后注册者被忽略。请检查配置。", ab);
                    continue;
                }
                _byId.Add(ab.Config.abilityId, ab);
            }
        }

        public EnemyAbilityBase Get(string abilityId)
        {
            if (string.IsNullOrEmpty(abilityId)) return null;
            _byId.TryGetValue(abilityId, out var ab);
            return ab;
        }

        public T Get<T>() where T : EnemyAbilityBase
        {
            for (int i = 0; i < _all.Count; i++)
                if (_all[i] is T t) return t;
            return null;
        }

        public bool Has(string abilityId) => _byId.ContainsKey(abilityId);

        public void InterruptAll(InterruptReason reason)
        {
            for (int i = 0; i < _all.Count; i++)
            {
                var ab = _all[i];
                if (ab != null && ab.IsRunning) ab.Interrupt(reason);
            }
        }

        /// <summary>
        /// 中断指定互斥组内所有正在执行的能力。
        /// 由 <see cref="EnemyAbilityBase"/> 在 Execute 开始时调用，确保同组互斥。
        /// </summary>
        public void InterruptGroup(string group, InterruptReason reason = InterruptReason.ExternalRequest)
        {
            if (string.IsNullOrEmpty(group)) return;
            for (int i = 0; i < _all.Count; i++)
            {
                var ab = _all[i];
                if (ab != null && ab.IsRunning && ab.Config?.exclusionGroup == group)
                    ab.Interrupt(reason);
            }
        }
    }
}