using UnityEngine;
using BaseGames.Core;
using BaseGames.Core.Pool;

namespace BaseGames.Combat
{
    /// <summary>
    /// 抛射物基类。子类通过重写 <see cref="OnInitialized"/> 设定初速度。
    /// 依赖 <see cref="HitBox"/> 子组件进行碰撞伤害检测。
    /// </summary>
    [RequireComponent(typeof(Rigidbody2D), typeof(HitBox))]
    public abstract class Projectile : MonoBehaviour
    {
        [HideInInspector] public DamageInfo          DamageInfo;
        [HideInInspector] public Vector2             Direction;

        protected ProjectileConfigSO _config;
        protected Rigidbody2D        _rb;
        protected HitBox             _hitBox;
        protected float              _aliveTimer;

        private PooledObject _pooledObject;

        protected virtual void Awake()
        {
            _rb           = GetComponent<Rigidbody2D>();
            _hitBox       = GetComponent<HitBox>();
            _pooledObject = GetComponent<PooledObject>();
        }

        /// <summary>从对象池取出后的初始化入口。</summary>
        public virtual void Initialize(ProjectileConfigSO config, DamageInfo damageInfo, Vector2 direction, int ownerLayer = 0)
        {
            _config    = config;
            DamageInfo = damageInfo;
            Direction  = direction.normalized;
            _aliveTimer = 0f;

            SetFactionLayer(ownerLayer);
            _hitBox.Activate(config.DamageSource);
            OnInitialized();
        }

        /// <summary>根据发射方所在 Layer 切换到对应的 PlayerProjectile / EnemyProjectile 层。</summary>
        private void SetFactionLayer(int ownerLayer)
        {
            int playerLayer     = LayerMask.NameToLayer("Player");
            int playerProjLayer = LayerMask.NameToLayer("PlayerProjectile");
            int enemyProjLayer  = LayerMask.NameToLayer("EnemyProjectile");
            if (playerProjLayer < 0 || enemyProjLayer < 0) return; // Layer 尚未创建，保留现有层
            gameObject.layer = (ownerLayer == playerLayer) ? playerProjLayer : enemyProjLayer;
        }

        /// <summary>
        /// 弹反：将投射物阵营从 EnemyProjectile 切换为 PlayerProjectile。
        /// 反转飞行方向，并重置 HitBox 命中记录使其能够命中新目标（敌人）。
        /// 由 HurtBox.ReceiveDamage() 在弹反成功后调用。
        /// </summary>
        public virtual void ReflectAsPlayerProjectile()
        {
            int playerProjLayer = LayerMask.NameToLayer("PlayerProjectile");
            if (playerProjLayer < 0) return;

            gameObject.layer = playerProjLayer;
            Direction = -Direction;
            _rb.velocity = -_rb.velocity;

            // 重置 HitBox 命中记录，确保反射后可命中新目标
            _hitBox.Deactivate();
            _hitBox.Activate(_config?.DamageSource);
        }

        protected virtual void OnInitialized() { }

        protected virtual void Update()
        {
            _aliveTimer += Time.deltaTime;
            if (_config != null && _aliveTimer >= _config.Lifetime)
                ReturnToPool();
        }

        /// <summary>停用并归还对象池。</summary>
        protected void ReturnToPool()
        {
            _hitBox.Deactivate();
            gameObject.SetActive(false);
            if (_pooledObject != null && _config != null)
                ServiceLocator.GetOrDefault<IObjectPoolService>()?.Despawn(_config.PoolKey, _pooledObject);
        }

        protected virtual void OnDisable()
        {
            _aliveTimer = 0f;
        }
    }
}