using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 程序开始时创建水面效果  同时管理水边界点位 便于精确的计算物体距离水源的距离
/// </summary>
public class WaterManager : MonoBehaviour
{
    public Transform borderPointParent;//计算距离用的边界点
    public float scale;
    private List<Vector3> allPointPos = new List<Vector3>();
    GameObject water;
    // Start is called before the first frame update
    void Start()
    {
        borderPointParent = this.transform.Find("BorderPoins");
        for (int i = 0; i < borderPointParent.childCount; i++)
        {
            allPointPos.Add(borderPointParent.GetChild(i).transform.position);//获取所有的点位
        }

        water = ResourcesCreater.InstantiatePrefab("WaterPrefab", this.transform);
        water.transform.localPosition = Vector3.zero;
        SetScale(scale);
    }

    /// <summary>
    /// 改变水面大小
    /// </summary>
    /// <param name="scale"></param>
    public void SetScale(float scale)
    {
        if (scale > 0)
        {
            if (water)
                water.transform.localScale = new Vector3(scale, 1, scale);
            else
                this.scale = scale;

        }
    }

    /// <summary>
    /// 获取距离湖中心的大概距离
    /// </summary>
    /// <returns></returns>
    public float GetDistanceFromWater(Vector3 worldPos)
    {
        return Vector3.Distance(worldPos, this.transform.position);
    }

    /// <summary>
    /// 获取距离湖边界的最近距离
    /// </summary>
    /// <returns></returns>
    public float GetNearestPointDistance(Vector3 worldPos)
    {
        //float sqrdistance = float.MaxValue;
        //for (int i = 0; i < allPointPos.Count; i++)//遍历寻找距离最近的点
        //{
        //    float currentPointSqrDis = (allPointPos[i] - worldPos).sqrMagnitude;
        //    if (currentPointSqrDis < sqrdistance)
        //        sqrdistance = currentPointSqrDis;
        //}
        //Debug.Log(Mathf.Sqrt(sqrdistance));
        //return Mathf.Sqrt(sqrdistance);
        Vector3 nearPointPos = ArrayHelper.Min(allPointPos.ToArray(), (p) => (p - worldPos).sqrMagnitude);
        float nearDis = Vector3.Distance(nearPointPos, worldPos);
        Debug.Log(nearDis);
        return nearDis;
    }
}