using UnityEngine;
using BaseGames.AI;

namespace BaseGames.Enemies
{
    /// <summary>
    /// 把 EnemyBase 的子系统包装成 BrainGraph 的能力接口（每敌人一实例）。
    /// 状态逻辑只依赖这些接口，不直接引用具体子系统。
    /// </summary>
    public sealed class EnemyBrainContext : IAiContext, ISensor, ICombatant, IActorVitals, IEnemyActor
    {
        readonly EnemyBase _enemy;
        readonly Blackboard _blackboard = new Blackboard();
        Vector2 _lastKnown;
        float _lostTimer;

        public EnemyBrainContext(EnemyBase enemy) { _enemy = enemy; }

        // ---- IAiContext ----
        public ISensor Sensor => this;
        public IEnemyLocomotion Locomotion => _enemy.Locomotion;
        public ICombatant Combat => this;
        public IActorVitals Vitals => this;
        public Blackboard Blackboard => _blackboard;

        /// <summary>每帧由 EnemyAiBrain 在 Tick 之前调用，维护最后已知位置与丢失计时（供需要的敌人用）。</summary>
        public void Refresh(float dt)
        {
            bool vision = InVisionZone();
            // 追逐区(aggro)或视野内都刷新最后已知位置：Approach 逼近态仅由 aggro 门控进入，
            // 若只在视野时刷新，aggro 先于视野命中时 Pursue 会拿到 zero/过期点而扑向错误位置。
            if ((vision || InChaseZone()) && _enemy.PlayerTransform != null)
                _lastKnown = _enemy.PlayerTransform.position;
            // 丢失计时仍以视野为准（LostFor 语义=脱离视野的时长，不受 aggro 影响）。
            if (vision) _lostTimer = 0f;
            else        _lostTimer += dt;
        }

        /// <summary>对象池复用时清空临时态。</summary>
        public void ResetScratch()
        {
            _blackboard.Clear();
            _lastKnown = _enemy.transform.position;
            _lostTimer = 0f;
        }

        // ---- ISensor ----（纯感知查询，转换由 AI 状态机决定）
        public bool InChaseZone() => _enemy.InChaseZone();
        public bool InVisionZone() => _enemy.InVisionZone();
        public bool SeesPlayer() => _enemy.IsPlayerVisible();
        public bool InRange(float range) => _enemy.IsPlayerInRange(range);
        public bool LostFor(float seconds) => !InVisionZone() && _lostTimer >= seconds;
        public Vector2 LastKnown => _lastKnown;

        // ---- ICombatant ----
        public bool UseAbility(string abilityId)
        {
            var a = _enemy.Abilities?.Get(abilityId);
            return a != null && a.Execute();
        }
        public bool IsAbilityRunning(string abilityId = null)
        {
            var reg = _enemy.Abilities;
            if (reg == null) return false;
            if (abilityId != null)
            {
                var a = reg.Get(abilityId);
                return a != null && a.IsRunning;
            }
            var all = reg.All;
            for (int i = 0; i < all.Count; i++)
                if (all[i].IsRunning) return true;
            return false;
        }
        public bool NoAbilityRunning => !IsAbilityRunning();
        public bool CanUseAbility(string abilityId)
        {
            var a = _enemy.Abilities?.Get(abilityId);
            return a != null && a.CanUse;
        }
        public void InterruptAbilities()
            => _enemy.Abilities?.InterruptAll(Abilities.InterruptReason.ExternalRequest);

        public bool HasEligibleAttack()
        {
            var sel = _enemy.AttackSelector;
            if (sel == null) return false;
            return sel.HasEligible(_enemy.IsPlayerVisible(), _enemy.Movement != null && _enemy.Movement.IsGrounded);
        }

        public bool UseBestAttack()
        {
            var sel = _enemy.AttackSelector;
            if (sel == null) return false;
            var mode = _enemy.StatsSO != null
                ? _enemy.StatsSO.attackSelectionMode
                : Abilities.AttackSelectionMode.WeightedRandom;
            bool grounded = _enemy.Movement != null && _enemy.Movement.IsGrounded;
            var pick = sel.Select(_enemy.IsPlayerVisible(), grounded, mode);
            return pick != null && pick.Execute();
        }

        // ---- IActorVitals ----
        public bool IsAlive => _enemy.IsAlive;
        public bool IsControllable => _enemy.CurrentState == EnemyStateType.Controlled;
        public float HpPercent
        {
            get
            {
                var stats = _enemy.Stats;
                return stats != null && stats.MaxHP > 0 ? (float)stats.CurrentHP / stats.MaxHP : 0f;
            }
        }
        public bool HpBelow(float ratio) => HpPercent < ratio;

        // ---- IEnemyActor ----
        public bool HasAlertState => _enemy.StatsSO != null && _enemy.StatsSO.HasAlertState;
    }
}