using UnityEngine;
using PathBerserker2d;
using BaseGames.Enemies;

namespace BaseGames.Enemies.Navigation
{
    /// <summary>
    /// PathBerserker2d 导航代理包装器（架构 07_EnemyModule §5）。
    /// 实现 IPathAgent 接口，使 EnemyBase 和 BD Task 无需直接依赖 PB2d 类型。
    /// PB2d API：UpdatePath(Vector2)、Stop()、TransformBasedMovement.movementSpeed、IsFollowingAPath。
    /// </summary>
    [RequireComponent(typeof(NavAgent))]
    [RequireComponent(typeof(TransformBasedMovement))]
    public class EnemyNavAgent : MonoBehaviour, IPathAgent
    {
        private NavAgent              _navAgent;
        private TransformBasedMovement _movement;

        /// <summary>正在沿路径移动时为 true。</summary>
        public bool IsMoving => _navAgent != null && _navAgent.IsFollowingAPath;

        public event System.Action OnNavPathFailed;

        private void Awake()
        {
            _navAgent = GetComponent<NavAgent>();
            _movement  = GetComponent<TransformBasedMovement>();
        }

        public void RequestMoveTo(Vector2 target)
        {
            _navAgent?.UpdatePath(target);
        }

        public void StopNavigation()
        {
            _navAgent?.Stop();
        }

        public bool IsAtDestination()
        {
            if (_navAgent == null) return true;
            // 已停止 OR 在目标线段上且不再跟随路径
            return _navAgent.IsIdle;
        }

        public void SetSpeed(float speed)
        {
            if (_movement != null) _movement.movementSpeed = speed;
        }

        public bool IsNearEdge()
        {
            // 双射线检测：脚下前方是否有地面
            if (_navAgent == null) return false;
            var origin = (Vector2)transform.position;
            var facing = transform.localScale.x >= 0f ? Vector2.right : Vector2.left;
            var groundMask = ~0; // 检测所有层；可收窄至 Ground 层
            bool groundAhead = Physics2D.Raycast(origin + facing * 0.3f, Vector2.down, 0.5f, groundMask);
            return !groundAhead;
        }
    }
}