using System.Collections.Generic;
using DG.Tweening;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// 图片飞向宝箱脚本
/// </summary>
public class FlyImage : MonoBehaviour
{
    private Vector3 endP;//终点
    private Vector3 p1;//控制点，来调节曲线效果

    private Vector3 startP;//
    private int index;
    private List<Vector3> point = new List<Vector3>();

    private RectTransform ts;
    /// <summary>
    /// Awake is called when the script instance is being loaded.
    /// </summary>
    void Awake()
    {
        tmpImage = transform.GetComponent<Image>();
        ts = transform.GetComponent<RectTransform>();
    }
    private Image tmpImage;
    /// <summary>
    /// 设置终点
    /// </summary>
    /// <param name="endP">终点</param>
    /// <param name="useBezier">是否使用贝塞尔</param>
    public void SetDestination(Sprite sp, Vector3 startP, Vector3 endP, bool useBezier)
    {
        tmpImage.sprite = sp;
        transform.position = startP;
        ts.localPosition += RandomPos();
        if (useBezier)
        {
            index = 0;
            //startP = transform.position;
            p1 = transform.position + GetOffect();

            point = new List<Vector3>();
            for (int i = 1; i < 101; i++)
            {
                Vector3 Bezierposition = BezierMath2(transform.position, p1, endP, (float)(i * 0.01));
                point.Add(Bezierposition);
            }

            Bezier_Move();
        }
        else
        {
            transform.DOMove(endP, 2f).SetEase(Ease.OutQuad).OnComplete(Close);
        }
    }

    bool isUp;
    private Vector3 RandomPos()
    {
        Vector3 tmpV = Vector3.zero;
        tmpV.x -= UnityEngine.Random.Range(10, 20);
        int a = UnityEngine.Random.Range(-20, 20);
        isUp = a > 0;
        tmpV.z += a;
        return tmpV;
    }

    private Vector3 GetOffect()
    {
        Vector3 tmpV = Vector3.zero;
        tmpV.x -= UnityEngine.Random.Range(10, 15);
        if (isUp)
        {
            tmpV.z += UnityEngine.Random.Range(20, 40);
        }
        else
        {
            tmpV.z -= UnityEngine.Random.Range(20, 40);
        }

        return tmpV;
    }

    /// <summary>
    /// 控制物体沿曲线移动
    /// </summary>
    private void Bezier_Move()
    {
        if (index + 2 >= point.Count)
        {
            //到终点了
            Close();
            return;
        }
        else
        {
            transform.DOMove(point[index], 0.01f).OnComplete(Bezier_Move);

            index += 2;
        }
    }

    private void Close()
    {
        //Debug.Log("到终点了,可以消失了");

        gameObject.SetActive(false);
    }

    /// <summary>
    /// 计算贝塞尔曲线
    /// </summary>
    /// <param name="startP">开始点</param>
    /// <param name="p1">控制点，来调节曲线效果</param>
    /// <param name="endP">终点</param>
    /// <param name="t">i * 0.01 100个点里面的比例</param>
    /// <returns></returns>
    private Vector3 BezierMath2(Vector3 startP, Vector3 p1, Vector3 endP, float t)
    {
        return (1 - t) * (1 - t) * startP + 2 * (1 - t) * t * p1 + t * t * endP;
    }

    // <summary>
    // 三次贝塞尔
    // </summary>
    public static Vector3 Bezier_3(Vector3 startP, Vector3 p1, Vector3 p2, Vector3 endP, float t)
    {
        return (1 - t) * ((1 - t) * ((1 - t) * startP + t * p1) + t * ((1 - t) * p1 + t * p2)) + t * ((1 - t) * ((1 - t) * p1 + t * p2) + t * ((1 - t) * p2 + t * endP));
    }
}