zeling_v2/Assets/_Game/Scripts/Enemies/AI/BD_InvestigateLastKnown.cs

#if GRAPH_DESIGNER
using UnityEngine;
using Opsive.BehaviorDesigner.Runtime.Tasks;
using Opsive.BehaviorDesigner.Runtime.Tasks.Actions;
using BaseGames.Enemies;

namespace BaseGames.Enemies.AI
{
    /// <summary>
    /// BD Action：多步搜查（Navigate → LookAround → RandomWalk × N）。
    ///
    /// <list type="bullet">
    ///   <item><b>Navigate</b>：导航至最后可见位置。</item>
    ///   <item><b>LookAround</b>：到达后原地环顾（播放 Look 动画，持续 LookAroundDuration）。</item>
    ///   <item><b>WalkRandom</b>：向搜查半径内的随机点移动，重复 RandomStepCount 次。</item>
    ///   <item>任意阶段重新发现玩家 → 返回 Failure，BD 树重入追击。</item>
    ///   <item>所有步骤完成仍未发现 → 返回 Success，BD 树归位/恢复巡逻。</item>
    /// </list>
    /// </summary>
    [TaskName("Investigate Last Known Pos")]
    [TaskCategory("BaseGames/Enemy/Movement")]
    [TaskDescription("多步搜查：导航到最后已知位置 → 环顾四周 → 随机游走 N 次")]
    public sealed class BD_InvestigateLastKnown : Action
    {
        [Tooltip("到达搜查点后环顾的时长（s）")]
        [SerializeField] private float m_LookAroundDuration = 0.8f;

        [Tooltip("随机行走步数（完成环顾后随机游荡的次数）")]
        [SerializeField] [Min(0)] private int m_RandomStepCount = 2;

        [Tooltip("随机行走半径（m）")]
        [SerializeField] private float m_SearchRadius = 2.5f;

        [Tooltip("到达目标点的判定半径（m）")]
        [SerializeField] private float m_ArriveRadius = 0.6f;

        private enum InvestigateSubStep { Navigate, LookAround, WalkRandom }

        private EnemyBase          _enemy;
        private InvestigateSubStep _step;
        private float              _stepTimer;
        private int                _stepsRemaining;
        private Vector2            _randomTarget;
        private bool               _pathFailed;
        private bool               _subscribed;

        public override void OnAwake() => _enemy = gameObject.GetComponent<EnemyBase>();

        public override void OnStart()
        {
            _enemy.SetAiPhase(AiPhase.Investigate);
            _step           = InvestigateSubStep.Navigate;
            _stepTimer      = 0f;
            _stepsRemaining = m_RandomStepCount;
            _pathFailed     = false;

            if (!_subscribed && _enemy.Nav != null)
            {
                _enemy.Nav.OnNavPathFailed += HandlePathFailed;
                _subscribed = true;
            }

            _enemy.MoveTo(_enemy.LastKnownPlayerPosition);
        }

        public override TaskStatus OnUpdate()
        {
            if (_enemy == null) return TaskStatus.Failure;

            if (_enemy.IsPlayerVisible()) return TaskStatus.Failure;

            switch (_step)
            {
                case InvestigateSubStep.Navigate:    return UpdateNavigate();
                case InvestigateSubStep.LookAround:  return UpdateLookAround();
                case InvestigateSubStep.WalkRandom:  return UpdateWalkRandom();
                default: return TaskStatus.Success;
            }
        }

        public override void OnEnd()
        {
            if (_subscribed && _enemy?.Nav != null)
                _enemy.Nav.OnNavPathFailed -= HandlePathFailed;
            _subscribed = false;
            _enemy?.StopMovement();
        }

        // ── 阶段逻辑 ────────────────────────────────────────────────────
        private TaskStatus UpdateNavigate()
        {
            Vector2 self = _enemy.transform.position;
            bool arrived = _pathFailed ||
                (self - _enemy.LastKnownPlayerPosition).sqrMagnitude <= m_ArriveRadius * m_ArriveRadius;

            if (!arrived) return TaskStatus.Running;

            _enemy.StopMovement();
            EnterLookAround();
            return TaskStatus.Running;
        }

        private TaskStatus UpdateLookAround()
        {
            _stepTimer += Time.deltaTime;
            if (_stepTimer < m_LookAroundDuration) return TaskStatus.Running;

            if (_stepsRemaining > 0)
                EnterRandomWalk();
            else
                return TaskStatus.Success;

            return TaskStatus.Running;
        }

        private TaskStatus UpdateWalkRandom()
        {
            Vector2 self    = _enemy.transform.position;
            bool    arrived = _pathFailed ||
                (self - _randomTarget).sqrMagnitude <= m_ArriveRadius * m_ArriveRadius;

            if (!arrived) return TaskStatus.Running;

            _enemy.StopMovement();
            _stepsRemaining--;
            _pathFailed = false;

            if (_stepsRemaining > 0)
                EnterRandomWalk();
            else
                return TaskStatus.Success;

            return TaskStatus.Running;
        }

        // ── 辅助方法 ────────────────────────────────────────────────────
        private void EnterLookAround()
        {
            _step      = InvestigateSubStep.LookAround;
            _stepTimer = 0f;
            _enemy.BeginLookAround();
        }

        private void EnterRandomWalk()
        {
            _step       = InvestigateSubStep.WalkRandom;
            _pathFailed = false;

            Vector2 origin = _enemy.LastKnownPlayerPosition;
            // 横板地形中只在水平方向随机偏移，保留 origin.y；
            // PathBerserker2d 寻路负责处理跨平台的纵向路径规划。
            float dir  = Random.value > 0.5f ? 1f : -1f;
            float dist = Random.Range(0.5f, m_SearchRadius);
            _randomTarget = new Vector2(origin.x + dir * dist, origin.y);

            _enemy.MoveTo(_randomTarget);
        }

        private void HandlePathFailed() => _pathFailed = true;
    }
}
#endif