using System.Collections.Generic;
using UnityEngine;
using BaseGames.Combat;

namespace BaseGames.Enemies
{
    /// <summary>
    /// 飞行敌人基类。
    ///
    /// 导航由 <see cref="Navigation.FlyingDirectNavigator"/> 实现（IPathAgent），
    /// AI 行为逻辑由挂载的 Behavior Designer 树驱动。
    /// 本类仅负责：
    /// <list type="bullet">
    ///   <item>Rigidbody2D 无重力初始化</item>
    ///   <item>接触伤害（OnTriggerStay2D）</item>
    ///   <item>StopMovement / MoveInDirection 的 Rigidbody2D 快速移动重写</item>
    /// </list>
    /// </summary>
    public class FlyingEnemy : EnemyBase
    {
        [Header("飞行移动（快速覆盖速度）")]
        [SerializeField] private float _moveSpeed = 3f;

        [Header("接触伤害")]
        [SerializeField] private DamageSourceSO _contactDamageSource;
        [Tooltip("对停留在体接触范围内的同一目标重复造成伤害的间隔（秒）。")]
        [SerializeField] private float _contactInterval = 0.5f;

        private Rigidbody2D _rb;
        // 按目标节流：避免 OnTriggerStay2D 每个物理帧都造成伤害（与 HitBox.Interval 节奏一致）
        private readonly Dictionary<HurtBox, float> _contactTimers = new();

        protected override void Awake()
        {
            base.Awake();
            _rb = GetComponent<Rigidbody2D>();
            if (_rb != null)
            {
                _rb.gravityScale = 0f;
                _rb.constraints  = RigidbodyConstraints2D.FreezeRotation;
            }
        }

        public override void StopMovement()
        {
            if (_rb != null) _rb.velocity = Vector2.zero;
        }

        public override void MoveInDirection(float dir)
        {
            if (_rb != null) _rb.velocity = new Vector2(dir * _moveSpeed, 0f);
        }

        private void OnTriggerStay2D(Collider2D other)
        {
            if (_contactDamageSource == null) return;
            if (CurrentState == EnemyStateType.Dead) return;
            if (_rb == null) return;

            var hurtBox = other.GetComponent<HurtBox>();
            if (hurtBox == null) return;

            // 按目标间隔节流：停留接触时每 _contactInterval 秒最多结算一次，
            // 不再每个物理帧都调用 ReceiveDamage（命中是否生效仍由承伤方无敌帧决定）。
            float now = Time.time;
            if (_contactTimers.TryGetValue(hurtBox, out float last) && now - last < _contactInterval) return;
            _contactTimers[hurtBox] = now;

            Vector2 knockDir = ((Vector2)other.bounds.center - _rb.position).normalized;
            var info = DamageInfo.From(
                _contactDamageSource,
                knockDir,
                transform.position,
                gameObject.layer);
            hurtBox.ReceiveDamage(info);
        }
    }
}