using UnityEngine;

namespace IndianOceanAssets.Engine2_5D
{
    // This class makes the camera follow a target transform with a specified offset.
    public class CameraFollow : MonoBehaviour
    {
        // The target Transform that the camera will follow.
        [SerializeField] private Transform target;
        // The positional offset from the target.
        [SerializeField] private Vector3 offset;

        [Tooltip("跟随平滑度（值越大跟随越紧密，10=几乎即时跟随）")]
        [SerializeField] private float followSmoothness = 20f;

        // Called once per frame — 使用 LateUpdate 确保在 FixedUpdate 物理移动之后执行，
        // 与 LightMaskSystem 的 LateUpdate 同步，避免光照抖动
        private void LateUpdate()
        {
            // If a target is assigned, smoothly move the camera towards the target's position plus the offset.
            if (target)
                transform.position = Vector3.Lerp(transform.position, target.position + offset, Time.deltaTime * followSmoothness);
        }

        /// <summary>
        /// 动态设置跟随目标（由 GameSpawnManager 调用）。
        /// </summary>
        public void SetTarget(Transform newTarget)
        {
            target = newTarget;
            // 立即跳到目标位置，避免平滑过渡导致的初始位置偏移
            if (newTarget != null)
                transform.position = newTarget.position + offset;
        }
    }
}